java Archives - Ebhor.com

Static keyword in Java

Static keyword can be used with

Variables
Methods
Blocks
Static inner class

lets see them one by one

Static Variable

Static variable can be create by adding static keyword in front of variable.

below count is static variable.

A static variable is shared among all objects of class.

Each class have their own instance variable but they all share static variables.

Static variable is also know as class variable because it belongs to class not specific to any object.

class Test {
    int a, b; //instance variable
    static int count; //class variable
    Test(int a, int b) {
        this.a = a; //a & b are local variables
        this.b = b;
        count++;
    }
    public void show() {
        System.out.println("a=" + a + " b=" + b + " count=" + count);
    }
}

public class StaticExample1 {
    public static void main(String[] s) {
        Test t = new Test(4, 5);
        t.show();

        Test t1 = new Test(6, 4);
        t1.show();
    }
}

class Test {

int a, b; //instance variable

static int count; //class variable

Test(int a, int b) {

this.a = a; //a & b are local variables

this.b = b;

count++;

}

public void show() {

System.out.println("a=" + a + " b=" + b + " count=" + count);

}

public class StaticExample1 {

public static void main(String[] s) {

Test t = new Test(4, 5);

t.show();

Test t1 = new Test(6, 4);

t1.show();

}

In diagram memory allocation for different variables are shown.

It also represents static variables are stored in MetaSpace( Java8 Onward ) from where all objects are sharing it.

Why Static variable required?

A static variable is shared amount all objects of class. So to share information amount objects static variable can used.

2. Static Method

To create a method static add static keyword before to method.

<access-specifier> static <return-type> <method-name>{
statements;
}

A static method can access only static fields and member functions.

class Test1 {
    int a, b;
    static int count;
    Test1(int a, int b) {
        this.a = a;
        this.b = b;
        count++;
    }
    public void show() {
        System.out.println("a=" + a + " b=" + b);
    }
    public static void test() {
        System.out.println("count is " + count);
     }
}
public class StaticExample2 {
    public static void main(String[] s) {

        Test1 t = new Test1(4, 5);
        t.show();
        Test1.test();

        Test1 t1 = new Test1(6, 4);
        t1.show();
        Test1.test();
    }
}

class Test1 {

int a, b;

static int count;

Test1(int a, int b) {

this.a = a;

this.b = b;

count++;

}

public void show() {

System.out.println("a=" + a + " b=" + b);

}

public static void test() {

System.out.println("count is " + count);

}

public class StaticExample2 {

public static void main(String[] s) {

Test1 t = new Test1(4, 5);

t.show();

Test1.test();

Test1 t1 = new Test1(6, 4);

t1.show();

Test1.test();

}

It can not access not static fields and methods.

Why Static method can not access not static variables?

Static variable initialize when a class in loaded in JVM

Instance variable is initialized when object is created.

At the time when static method called Instance variables they are not created. Thats why static method can not access instance variable.

3. Static Block

A block is set of statements inside opening closing brackets {….}.

A static block is a block which contains static in front.

public class StaticExample3{
        static{
	          System.out.println("Inside static");
			  }
	 public static void main(String[] s){
              System.out.println("Inside main");
	   }
}

public class StaticExample3{

static{

System.out.println("Inside static");

}

public static void main(String[] s){

System.out.println("Inside main");

}

Why Static block is needed?

A static block can be used to initialize some values that a program required during load time or in throughout the program.

4. Static Inner class

A class inside a class in called nested class java supports both static and non static nested classes.

A static nested class is nested class with preceded static keyword.

class Outer{
     void show(){
	 System.out.println("Inside show() in Outer class");
	 }
	 public static class StaticInner{
		void display(){
	 System.out.println("Inside display() in Inner class");
	 } 
	 }
}

public class TestMain{
	public static void main(String[] s){
		Outer outer=new Outer();
		outer.show();
		Outer.StaticInner staticInner=new Outer.StaticInner();
		staticInner.display();
	}
}

class Outer{

void show(){

System.out.println("Inside show() in Outer class");

}

public static class StaticInner{

void display(){

System.out.println("Inside display() in Inner class");

}

public class TestMain{

public static void main(String[] s){

Outer outer=new Outer();

outer.show();

Outer.StaticInner staticInner=new Outer.StaticInner();

staticInner.display();

}

Output

Inside show() in Outer class
Inside display() in Inner class

1 2	Inside show() in Outer class Inside display() in Inner class

Java code for inserting data into database

Java code for inserting data into database is done using Jdbc(Java Database connectivity).

Jdbc is a API to connect java program to various databases like MySql, Oracle, MSAccess etc.

Here Step by step tutorial to insert data from java to database.

Here MySql or MariaDB database is used for this purpose.

So to insert data in database we need to set in two end

Create Database and table
Write Java (JDBC) code

Lets see them one by one

Create Database and table

Open phpMyAdmin click on home icon or left side

Click to SQL on middle menu.

Write create query given below

CREATE USER 'ebhor_user'@'localhost' IDENTIFIED BY '21V6';
GRANT ALL ON *.* TO 'ebhor_user'@'localhost';

create database ebhor;
use ebhor;
create table student(
id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
roll_no bigint(20) unsigned NOT NULL,
name varchar(100) NOT NULL,
branch varchar(25) NOT NULL,
section varchar(3),
email_id varchar(100),
dob date,
mobile_no varchar(12),
add_date timestamp DEFAULT CURRENT_TIMESTAMP,
primary key(id),
unique key(mobile_no),
unique key(email_id)
)ENGINE=InnoDB DEFAULT CHARSET=utf8;

CREATE USER 'ebhor_user'@'localhost' IDENTIFIED BY '21V6';

GRANT ALL ON *.* TO 'ebhor_user'@'localhost';

create database ebhor;

use ebhor;

create table student(

id bigint(20) unsigned NOT NULL AUTO_INCREMENT,

roll_no bigint(20) unsigned NOT NULL,

name varchar(100) NOT NULL,

branch varchar(25) NOT NULL,

section varchar(3),

email_id varchar(100),

dob date,

mobile_no varchar(12),

add_date timestamp DEFAULT CURRENT_TIMESTAMP,

primary key(id),

unique key(mobile_no),

unique key(email_id)

)ENGINE=InnoDB DEFAULT CHARSET=utf8;

Copy and insert above code in SQL query box

After click on go button it will show below box if query is successfully executed.

You can see structure of table. which show below output.

Now table is created.

Write JDBC Code

Steps for JDBC is as below

import JDBC classes
Load and register JDBC Driver
Open Database connection
Create Statement object to pass query
Execute Statement
Get the result
Close connections

File Structure of Program

Importing JDBC classes

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Connection;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.SQLException;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.SQLException;

import java.sql.Connection;

import java.sql.Date;

import java.sql.PreparedStatement;

import java.sql.SQLException;

Load and register JDBC Driver

Here Class.forName() is used to load and register driver

import java.sql.Connection;
Class.forName("com.mysql.jdbc.Driver");

1 2	import java.sql.Connection; Class.forName("com.mysql.jdbc.Driver");

Open Database connection

DriverManager.getConnection("jdbc:mysql://localhost:3306/ebhor?useUnicode=true&characterEncoding=UTF-8", "ebhor_user", "21V6");

1	DriverManager.getConnection("jdbc:mysql://localhost:3306/ebhor?useUnicode=true&characterEncoding=UTF-8", "ebhor_user", "21V6");

Create Statement object to pass query

PreparedStatement ps=con.prepareStatement(query);

1	PreparedStatement ps=con.prepareStatement(query);

Execute Statement and get result

Here ps.executeUpdate() execute query and get no of row affected.

int st=ps.executeUpdate();

1	int st=ps.executeUpdate();

Close connections

pre class=”theme:eclipse font:verdana toolbar:2 show-plain:3 lang:java decode:true”> con.close();

Insert a Student Object into database

Before proceeding add mysql-connector-java-5.1.14-bin.jar to your class path.

All file details are as below.

Student.java

Student object that contains basic properties of students like id, rollNo, name, branch,section, emailId,dob, mobileNo, addDate.

package com.ebhor.model;
import java.io.Serializable;
import java.sql.Date;
import java.sql.Timestamp;

public class Student implements Serializable {
    long id;
    long rollNo;
    String name;
    String branch;
    String section;
    String emailId;
    Date dob;
    String mobileNo;
    Timestamp addDate;

    public Student() {

    }

    public Student(long rollNo, String name, String branch, String section, String emailId, Date dob, String mobileNo) {
        this.rollNo = rollNo;
        this.name = name;
        this.branch = branch;
        this.section = section;
        this.emailId = emailId;
        this.dob = dob;
        this.mobileNo = mobileNo;
    }

    public Student(long id, long rollNo, String name, String branch, String section, String emailId, Date dob, String mobileNo, Timestamp addDate) {
        this.id = id;
        this.rollNo = rollNo;
        this.name = name;
        this.branch = branch;
        this.section = section;
        this.emailId = emailId;
        this.dob = dob;
        this.mobileNo = mobileNo;
        this.addDate = addDate;
    }
@Override
    public String toString() {
        return "Student{" + "id=" + id + ", rollNo=" + rollNo + ", name=" + name + ", branch=" + branch + ", section=" + section + ", emailId=" + emailId + ", dob=" + dob + ", mobileNo=" + mobileNo + ", addDate=" + addDate + '}';
    }

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }
    public long getRollNo() {
        return rollNo;
    }

    public void setRollNo(long rollNo) {
        this.rollNo = rollNo;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getBranch() {
        return branch;
    }

    public void setBranch(String branch) {
        this.branch = branch;
    }

    public String getSection() {
        return section;
    }

    public void setSection(String section) {
        this.section = section;
    }

    public String getEmailId() {
        return emailId;
    }

    public void setEmailId(String emailId) {
        this.emailId = emailId;
    }

    public Date getDob() {
        return dob;
    }

    public void setDob(Date dob) {
        this.dob = dob;
    }

    public String getMobileNo() {
        return mobileNo;
    }

    public void setMobileNo(String mobileNo) {
        this.mobileNo = mobileNo;
    }

    public Timestamp getAddDate() {
        return addDate;
    }

    public void setAddDate(Timestamp addDate) {
        this.addDate = addDate;
    }

}

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

package com.ebhor.model;

import java.io.Serializable;

import java.sql.Date;

import java.sql.Timestamp;

public class Student implements Serializable {

long id;

long rollNo;

String name;

String branch;

String section;

String emailId;

Date dob;

String mobileNo;

Timestamp addDate;

public Student() {

}

public Student(long rollNo, String name, String branch, String section, String emailId, Date dob, String mobileNo) {

this.rollNo = rollNo;

this.name = name;

this.branch = branch;

this.section = section;

this.emailId = emailId;

this.dob = dob;

this.mobileNo = mobileNo;

}

public Student(long id, long rollNo, String name, String branch, String section, String emailId, Date dob, String mobileNo, Timestamp addDate) {

this.id = id;

this.rollNo = rollNo;

this.name = name;

this.branch = branch;

this.section = section;

this.emailId = emailId;

this.dob = dob;

this.mobileNo = mobileNo;

this.addDate = addDate;

}

@Override

public String toString() {

return "Student{" + "id=" + id + ", rollNo=" + rollNo + ", name=" + name + ", branch=" + branch + ", section=" + section + ", emailId=" + emailId + ", dob=" + dob + ", mobileNo=" + mobileNo + ", addDate=" + addDate + '}';

}

public long getId() {

return id;

}

public void setId(long id) {

this.id = id;

}

public long getRollNo() {

return rollNo;

}

public void setRollNo(long rollNo) {

this.rollNo = rollNo;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getBranch() {

return branch;

}

public void setBranch(String branch) {

this.branch = branch;

}

public String getSection() {

return section;

}

public void setSection(String section) {

this.section = section;

}

public String getEmailId() {

return emailId;

}

public void setEmailId(String emailId) {

this.emailId = emailId;

}

public Date getDob() {

return dob;

}

public void setDob(Date dob) {

this.dob = dob;

}

public String getMobileNo() {

return mobileNo;

}

public void setMobileNo(String mobileNo) {

this.mobileNo = mobileNo;

}

public Timestamp getAddDate() {

return addDate;

}

public void setAddDate(Timestamp addDate) {

this.addDate = addDate;

}

ConnectionFactory .java

This file is responsible to connect with MySql database, after getting connection this will return connection object

package com.ebhor.dababase;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class ConnectionFactory {

    public static Connection getConnection() {
        Connection c = null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            c = DriverManager.getConnection("jdbc:mysql://localhost:3306/ebhor?useUnicode=true&characterEncoding=UTF-8", "ebhor_user", "21V6");
        } catch (ClassNotFoundException e) {
            System.out.println("ClassNotFoundException " + e);
        } catch (SQLException e) {
            System.out.println("SQLException " + e);
        }
        return c;
    }
}

package com.ebhor.dababase;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.SQLException;

public class ConnectionFactory {

public static Connection getConnection() {

Connection c = null;

try {

Class.forName("com.mysql.jdbc.Driver");

c = DriverManager.getConnection("jdbc:mysql://localhost:3306/ebhor?useUnicode=true&characterEncoding=UTF-8", "ebhor_user", "21V6");

} catch (ClassNotFoundException e) {

System.out.println("ClassNotFoundException " + e);

} catch (SQLException e) {

System.out.println("SQLException " + e);

}

return c;

}

StudentJDBCInsert.java

This class will get connection from ConnectionFactory and insert data in database and return no of rows inserted in database.

package com.ebhor.dababase;


import com.ebhor.model.Student;
import com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException;
import java.sql.Connection;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class StudentJDBCInsert {

    public static void main(String[] args) {
        Connection con = ConnectionFactory.getConnection();
        con = ConnectionFactory.getConnection();
        PreparedStatement ps = null;
        int st = 0;
        Student student = new Student(1, "Ram", "CSE", "A", "ram@ebhor.com", Date.valueOf("2020-02-04"), "1234567891");
        try {
            String query = "insert into student(roll_no,name,branch,section,email_id,dob,mobile_no) "
                    + "values(?,?,?,?,?,?,?)";
            ps = con.prepareStatement(query);
            ps.setLong(1, student.getRollNo());
            ps.setString(2, student.getName());
            ps.setString(3, student.getBranch());
            ps.setString(4, student.getSection());
            ps.setString(5, student.getEmailId());
            ps.setDate(6, student.getDob());
            ps.setString(7, student.getMobileNo());
            st = ps.executeUpdate();
            System.out.println("inserted student " + st);
        } catch (MySQLIntegrityConstraintViolationException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                con.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }

    }
}

package com.ebhor.dababase;

import com.ebhor.model.Student;

import com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException;

import java.sql.Connection;

import java.sql.Date;

import java.sql.PreparedStatement;

import java.sql.SQLException;

public class StudentJDBCInsert {

public static void main(String[] args) {

Connection con = ConnectionFactory.getConnection();

con = ConnectionFactory.getConnection();

PreparedStatement ps = null;

int st = 0;

Student student = new Student(1, "Ram", "CSE", "A", "[email protected]", Date.valueOf("2020-02-04"), "1234567891");

try {

String query = "insert into student(roll_no,name,branch,section,email_id,dob,mobile_no) "

+ "values(?,?,?,?,?,?,?)";

ps = con.prepareStatement(query);

ps.setLong(1, student.getRollNo());

ps.setString(2, student.getName());

ps.setString(3, student.getBranch());

ps.setString(4, student.getSection());

ps.setString(5, student.getEmailId());

ps.setDate(6, student.getDob());

ps.setString(7, student.getMobileNo());

st = ps.executeUpdate();

System.out.println("inserted student " + st);

} catch (MySQLIntegrityConstraintViolationException e) {

e.printStackTrace();

} catch (Exception e) {

e.printStackTrace();

} finally {

try {

con.close();

} catch (SQLException ex) {

ex.printStackTrace();

}

Output

inserted student 1

1	inserted student 1

Insert multiple Student Objects into database

efficient way to insert multiple records in database is using batch processing

Steps to store multiple records in database

Create multiple objects
Add all to a List
Add list item to batch
executeBatch()

StudnetJDBCBatchInsert.java

this program will insert batch data to MySql database

package com.ebhor.dababase;

import com.ebhor.model.Student;
import com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException;
import java.sql.Connection;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

public class StudentJDBCBatchInsert {

    public static void main(String[] args) {
        Connection con = ConnectionFactory.getConnection();
        con = ConnectionFactory.getConnection();
        PreparedStatement ps = null;
        int batchSize = 50;
        int st[];
        Student student1 = new Student(2, "Sohan", "CSE", "A", "sohan@ebhor.com", Date.valueOf("2001-01-05"), "17666567591");
        Student student2 = new Student(3, "Rohan", "Mech", "A", "rohan@ebhor.com", Date.valueOf("2001-02-03"), "1434667591");
        Student student3 = new Student(4, "Nita", "Mech", "A", "nita@ebhor.com", Date.valueOf("2001-04-03"), "1434517591");
        Student student4 = new Student(5, "Rita", "Civil", "A", "rita@ebhor.com", Date.valueOf("2002-01-02"), "1434563591");
        Student student5 = new Student(6, "Mona", "Mech", "A", "mona@ebhor.com", Date.valueOf("2002-03-01"), "1434514621");
        List<Student> studentArray = new ArrayList<Student>();
        studentArray.add(student1);
        studentArray.add(student2);
        studentArray.add(student3);
        studentArray.add(student4);
        studentArray.add(student5);

        try {
            String query = "insert into student(roll_no,name,branch,section,email_id,dob,mobile_no) "
                    + "values(?,?,?,?,?,?,?)";
            con.setAutoCommit(false);
            ps = con.prepareStatement(query);
            for (Student student : studentArray) {
                ps.setLong(1, student.getRollNo());
                ps.setString(2, student.getName());
                ps.setString(3, student.getBranch());
                ps.setString(4, student.getSection());
                ps.setString(5, student.getEmailId());
                ps.setDate(6, student.getDob());
                ps.setString(7, student.getMobileNo());
                ps.addBatch();
            }
            st = ps.executeBatch();
            con.commit();
            for (int i : st) {
                System.out.println("inserted student " + i);
            }
        } catch (MySQLIntegrityConstraintViolationException e) {
            try {
                con.rollback();
            } catch (SQLException ex) {
                Logger.getLogger(StudentJDBCBatchInsert.class.getName()).log(Level.SEVERE, null, ex);
            }
            e.printStackTrace();
        } catch (Exception e) {
            try {
                con.rollback();
            } catch (SQLException ex) {
                Logger.getLogger(StudentJDBCBatchInsert.class.getName()).log(Level.SEVERE, null, ex);
            }
            e.printStackTrace();
        } finally {
            try {
                con.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }

    }
}

package com.ebhor.dababase;

import com.ebhor.model.Student;

import com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException;

import java.sql.Connection;

import java.sql.Date;

import java.sql.PreparedStatement;

import java.sql.SQLException;

import java.util.ArrayList;

import java.util.List;

import java.util.logging.Level;

import java.util.logging.Logger;

public class StudentJDBCBatchInsert {

public static void main(String[] args) {

Connection con = ConnectionFactory.getConnection();

con = ConnectionFactory.getConnection();

PreparedStatement ps = null;

int batchSize = 50;

int st[];

Student student1 = new Student(2, "Sohan", "CSE", "A", "[email protected]", Date.valueOf("2001-01-05"), "17666567591");

Student student2 = new Student(3, "Rohan", "Mech", "A", "[email protected]", Date.valueOf("2001-02-03"), "1434667591");

Student student3 = new Student(4, "Nita", "Mech", "A", "[email protected]", Date.valueOf("2001-04-03"), "1434517591");

Student student4 = new Student(5, "Rita", "Civil", "A", "[email protected]", Date.valueOf("2002-01-02"), "1434563591");

Student student5 = new Student(6, "Mona", "Mech", "A", "[email protected]", Date.valueOf("2002-03-01"), "1434514621");

List<Student> studentArray = new ArrayList<Student>();

studentArray.add(student1);

studentArray.add(student2);

studentArray.add(student3);

studentArray.add(student4);

studentArray.add(student5);

try {

String query = "insert into student(roll_no,name,branch,section,email_id,dob,mobile_no) "

+ "values(?,?,?,?,?,?,?)";

con.setAutoCommit(false);

ps = con.prepareStatement(query);

for (Student student : studentArray) {

ps.setLong(1, student.getRollNo());

ps.setString(2, student.getName());

ps.setString(3, student.getBranch());

ps.setString(4, student.getSection());

ps.setString(5, student.getEmailId());

ps.setDate(6, student.getDob());

ps.setString(7, student.getMobileNo());

ps.addBatch();

}

st = ps.executeBatch();

con.commit();

for (int i : st) {

System.out.println("inserted student " + i);

}

} catch (MySQLIntegrityConstraintViolationException e) {

try {

con.rollback();

} catch (SQLException ex) {

Logger.getLogger(StudentJDBCBatchInsert.class.getName()).log(Level.SEVERE, null, ex);

}

e.printStackTrace();

} catch (Exception e) {

try {

con.rollback();

} catch (SQLException ex) {

Logger.getLogger(StudentJDBCBatchInsert.class.getName()).log(Level.SEVERE, null, ex);

}

e.printStackTrace();

} finally {

try {

con.close();

} catch (SQLException ex) {

ex.printStackTrace();

}

Output

<pre class="theme:eclipse font:verdana toolbar:2
 show-plain:3 lang:default decode:true">
inserted student 1
inserted student 1
inserted student 1
inserted student 1
inserted student 1

<pre class="theme:eclipse font:verdana toolbar:2

show-plain:3 lang:default decode:true">

inserted student 1

MySql Admin view

Reading Data using JDBC

StudentJDBCRead .java

This program read student records from database table and show in java console.

package com.ebhor.dababase;

import com.ebhor.model.Student;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class StudentJDBCRead {

    public static void main(String[] args) {

        Connection con = ConnectionFactory.getConnection();
        con = ConnectionFactory.getConnection();
        PreparedStatement ps = null;
        List<Student> studentList = new ArrayList<Student>();
        try {
            String query = "select * from student";
            ps = con.prepareStatement(query);
            ResultSet rs = ps.executeQuery();
            while (rs.next()) {
                Student student = new Student();
                student.setId(rs.getLong("id"));
                student.setRollNo(rs.getLong("roll_no"));
                student.setName(rs.getString("name"));
                student.setBranch(rs.getString("branch"));
                student.setSection(rs.getString("section"));
                student.setEmailId(rs.getString("email_id"));
                student.setDob(rs.getDate("dob"));
                student.setMobileNo(rs.getString("mobile_no"));
                student.setAddDate(rs.getTimestamp("add_date"));
                studentList.add(student);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                con.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }

        System.out.println("Student details are");
        for (Student student : studentList) {
            System.out.println(student);
        }
    }

}

package com.ebhor.dababase;

import com.ebhor.model.Student;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.util.ArrayList;

import java.util.List;

public class StudentJDBCRead {

public static void main(String[] args) {

Connection con = ConnectionFactory.getConnection();

con = ConnectionFactory.getConnection();

PreparedStatement ps = null;

List<Student> studentList = new ArrayList<Student>();

try {

String query = "select * from student";

ps = con.prepareStatement(query);

ResultSet rs = ps.executeQuery();

while (rs.next()) {

Student student = new Student();

student.setId(rs.getLong("id"));

student.setRollNo(rs.getLong("roll_no"));

student.setName(rs.getString("name"));

student.setBranch(rs.getString("branch"));

student.setSection(rs.getString("section"));

student.setEmailId(rs.getString("email_id"));

student.setDob(rs.getDate("dob"));

student.setMobileNo(rs.getString("mobile_no"));

student.setAddDate(rs.getTimestamp("add_date"));

studentList.add(student);

}

} catch (Exception e) {

e.printStackTrace();

} finally {

try {

con.close();

} catch (SQLException ex) {

ex.printStackTrace();

}

System.out.println("Student details are");

for (Student student : studentList) {

System.out.println(student);

}

Output

Student details are
Student{id=22, rollNo=1, name=Ram, branch=CSE, section=A, emailId=ram@ebhor.com, dob=2020-02-04, mobileNo=1234567891, addDate=2020-08-07 16:38:11.0}
Student{id=23, rollNo=2, name=Sohan, branch=CSE, section=A, emailId=sohan@ebhor.com, dob=2001-01-05, mobileNo=17666567591, addDate=2020-08-07 16:38:50.0}
Student{id=24, rollNo=3, name=Rohan, branch=Mech, section=A, emailId=rohan@ebhor.com, dob=2001-02-03, mobileNo=1434667591, addDate=2020-08-07 16:38:50.0}
Student{id=25, rollNo=4, name=Nita, branch=Mech, section=A, emailId=nita@ebhor.com, dob=2001-04-03, mobileNo=1434517591, addDate=2020-08-07 16:38:50.0}
Student{id=26, rollNo=5, name=Rita, branch=Civil, section=A, emailId=rita@ebhor.com, dob=2002-01-02, mobileNo=1434563591, addDate=2020-08-07 16:38:50.0}
Student{id=27, rollNo=6, name=Mona, branch=Mech, section=A, emailId=mona@ebhor.com, dob=2002-03-01, mobileNo=1434514621, addDate=2020-08-07 16:38:50.0}

Student details are

Student{id=22, rollNo=1, name=Ram, branch=CSE, section=A, emailId=ram@ebhor.com, dob=2020-02-04, mobileNo=1234567891, addDate=2020-08-07 16:38:11.0}

Student{id=23, rollNo=2, name=Sohan, branch=CSE, section=A, emailId=sohan@ebhor.com, dob=2001-01-05, mobileNo=17666567591, addDate=2020-08-07 16:38:50.0}

Student{id=24, rollNo=3, name=Rohan, branch=Mech, section=A, emailId=rohan@ebhor.com, dob=2001-02-03, mobileNo=1434667591, addDate=2020-08-07 16:38:50.0}

Student{id=25, rollNo=4, name=Nita, branch=Mech, section=A, emailId=nita@ebhor.com, dob=2001-04-03, mobileNo=1434517591, addDate=2020-08-07 16:38:50.0}

Student{id=26, rollNo=5, name=Rita, branch=Civil, section=A, emailId=rita@ebhor.com, dob=2002-01-02, mobileNo=1434563591, addDate=2020-08-07 16:38:50.0}

Student{id=27, rollNo=6, name=Mona, branch=Mech, section=A, emailId=mona@ebhor.com, dob=2002-03-01, mobileNo=1434514621, addDate=2020-08-07 16:38:50.0}

Download above code fron github

Employee details program in java

Employee detail program in java as as below.

Here two classes are created

Employee class
EmployeeMain class

Details of these two classes are as below

Employee.java

This class contains various field of employees like id, fname, lname, address etc.

Its corresponding getter and setter method is created in program.

Employee.java is a java bean and it good example of java encapsulation.

fields of Employee object can not be directly accessible outside the class to access this we need getter and setter methods.

Default and parameterized constructor are created to initialize employee object.

toString() of Object class is overridden to convert object to String.

Some fields like hra, providentFund and grossSalary are calculated from basicSalary.

So user provides only basicSalary value and other derived values are calculated based on it.

Two different methods are used to initialize values(Parameterised constructor and setter methods).

So calculation of derived values are done inside constructor and in setter method.

Providing addDate value is optional for user it user does not provide this value constructor or setter method does this.

import java.math.BigDecimal;
import java.sql.Date;
import java.sql.Timestamp;
import java.io.Serializable;

public class Employee implements Serializable{

    private long id;
    private String fname;
    private String lname;
    private String address;
    private String mobileNo;
    private String mailId;
    private String city;
    private String designation;
    private Date dob;
    private Date doj;
    private BigDecimal basicSalary;
    private BigDecimal hra; //40 % of basic
    private BigDecimal providentFund;// 12% of basic
    private BigDecimal grossSalary;//sum of basic+allowance(hra+providentFund)
    private Timestamp addDate;

    public Employee() {
    }

    public Employee(String fname, String lname, String address, String mobileNo, String mailId, String city, String designation, Date dob, Date doj, BigDecimal basicSalary) {

        this.fname = fname;
        this.lname = lname;
        this.address = address;
        this.mobileNo = mobileNo;
        this.mailId = mailId;
        this.city = city;
        this.designation = designation;
        this.dob = dob;
        this.doj = doj;
        this.basicSalary = basicSalary;
        hra = basicSalary.multiply(new BigDecimal(0.12).setScale(2, BigDecimal.ROUND_UP));
        providentFund = basicSalary.multiply(new BigDecimal(0.40).setScale(2, BigDecimal.ROUND_UP));
        grossSalary = basicSalary.add(hra).add(providentFund).setScale(2, BigDecimal.ROUND_UP);
        if (addDate == null) {
            this.addDate = new Timestamp(System.currentTimeMillis());
        } else {
            this.addDate = addDate;
        }
    }

    public Employee(long id, String fname, String lname, String address, String mobileNo, String mailId, String city, String designation, Date dob, Date doj, BigDecimal basicSalary, Timestamp addDate) {
        this.id = id;
        this.fname = fname;
        this.lname = lname;
        this.address = address;
        this.mobileNo = mobileNo;
        this.mailId = mailId;
        this.city = city;
        this.designation = designation;
        this.dob = dob;
        this.doj = doj;
        this.basicSalary = basicSalary;
        hra = basicSalary.multiply(new BigDecimal(0.12).setScale(2, BigDecimal.ROUND_UP));
        providentFund = basicSalary.multiply(new BigDecimal(0.40).setScale(2, BigDecimal.ROUND_UP));
        grossSalary = basicSalary.add(hra).add(providentFund).setScale(2, BigDecimal.ROUND_UP);
        if (addDate == null) {
            this.addDate = new Timestamp(System.currentTimeMillis());
        } else {
            this.addDate = addDate;
        }
    }

    @Override
    public String toString() {
        return "Employee{" + "id=" + id + ", fname=" + fname + ", lname=" + lname + ", address=" + address + ", mobileNo=" + mobileNo + ", mailId=" + mailId + ", city=" + city + ", designation=" + designation + ", dob=" + dob + ", doj=" + doj + ", basicSalary=" + basicSalary + ", hra=" + hra + ", providentFund=" + providentFund + ", grossSalary=" + grossSalary + ", addDate=" + addDate + '}';
    }

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

    public String getFname() {
        return fname;
    }

    public void setFname(String fname) {
        this.fname = fname;
    }

    public String getLname() {
        return lname;
    }

    public void setLname(String lname) {
        this.lname = lname;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getMobileNo() {
        return mobileNo;
    }

    public void setMobileNo(String mobileNo) {
        this.mobileNo = mobileNo;
    }

    public String getMailId() {
        return mailId;
    }

    public void setMailId(String mailId) {
        this.mailId = mailId;
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public Timestamp getAddDate() {
        return addDate;
    }

    public void setAddDate(Timestamp addDate) {
    }

    public String getDesignation() {
        return designation;
    }

    public void setDesignation(String designation) {
        this.designation = designation;
    }

    public Date getDob() {
        return dob;
    }

    public void setDob(Date dob) {
        this.dob = dob;
    }

    public Date getDoj() {
        return doj;
    }

    public void setDoj(Date doj) {
        this.doj = doj;
    }

    public BigDecimal getBasicSalary() {
        return basicSalary;
    }

    public void setBasicSalary(BigDecimal basicSalary) {
        this.basicSalary = basicSalary;
        //calculating hra and PF
        setHra(basicSalary.multiply(new BigDecimal("0.40")));
        setProvidentFund(basicSalary.multiply(new BigDecimal("0.12")));
        setGrossSalary(basicSalary.add(getHra().add(getProvidentFund())));
        if (addDate == null) {
            this.addDate = new Timestamp(System.currentTimeMillis());
        } else {
            this.addDate = addDate;
        }
    }

    public BigDecimal getHra() {
        return hra;
    }

    public void setHra(BigDecimal hra) {
        this.hra = hra;
    }

    public BigDecimal getProvidentFund() {
        return providentFund;
    }

    public void setProvidentFund(BigDecimal providentFund) {
        this.providentFund = providentFund;
    }

    public BigDecimal getGrossSalary() {
        return grossSalary;
    }

    public void setGrossSalary(BigDecimal grossSalary) {
        this.grossSalary = grossSalary;
    }

}

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

import java.math.BigDecimal;

import java.sql.Date;

import java.sql.Timestamp;

import java.io.Serializable;

public class Employee implements Serializable{

private long id;

private String fname;

private String lname;

private String address;

private String mobileNo;

private String mailId;

private String city;

private String designation;

private Date dob;

private Date doj;

private BigDecimal basicSalary;

private BigDecimal hra; //40 % of basic

private BigDecimal providentFund;// 12% of basic

private BigDecimal grossSalary;//sum of basic+allowance(hra+providentFund)

private Timestamp addDate;

public Employee() {

}

public Employee(String fname, String lname, String address, String mobileNo, String mailId, String city, String designation, Date dob, Date doj, BigDecimal basicSalary) {

this.fname = fname;

this.lname = lname;

this.address = address;

this.mobileNo = mobileNo;

this.mailId = mailId;

this.city = city;

this.designation = designation;

this.dob = dob;

this.doj = doj;

this.basicSalary = basicSalary;

hra = basicSalary.multiply(new BigDecimal(0.12).setScale(2, BigDecimal.ROUND_UP));

providentFund = basicSalary.multiply(new BigDecimal(0.40).setScale(2, BigDecimal.ROUND_UP));

grossSalary = basicSalary.add(hra).add(providentFund).setScale(2, BigDecimal.ROUND_UP);

if (addDate == null) {

this.addDate = new Timestamp(System.currentTimeMillis());

} else {

this.addDate = addDate;

}

public Employee(long id, String fname, String lname, String address, String mobileNo, String mailId, String city, String designation, Date dob, Date doj, BigDecimal basicSalary, Timestamp addDate) {

this.id = id;

this.fname = fname;

this.lname = lname;

this.address = address;

this.mobileNo = mobileNo;

this.mailId = mailId;

this.city = city;

this.designation = designation;

this.dob = dob;

this.doj = doj;

this.basicSalary = basicSalary;

hra = basicSalary.multiply(new BigDecimal(0.12).setScale(2, BigDecimal.ROUND_UP));

providentFund = basicSalary.multiply(new BigDecimal(0.40).setScale(2, BigDecimal.ROUND_UP));

grossSalary = basicSalary.add(hra).add(providentFund).setScale(2, BigDecimal.ROUND_UP);

if (addDate == null) {

this.addDate = new Timestamp(System.currentTimeMillis());

} else {

this.addDate = addDate;

}

@Override

public String toString() {

return "Employee{" + "id=" + id + ", fname=" + fname + ", lname=" + lname + ", address=" + address + ", mobileNo=" + mobileNo + ", mailId=" + mailId + ", city=" + city + ", designation=" + designation + ", dob=" + dob + ", doj=" + doj + ", basicSalary=" + basicSalary + ", hra=" + hra + ", providentFund=" + providentFund + ", grossSalary=" + grossSalary + ", addDate=" + addDate + '}';

}

public long getId() {

return id;

}

public void setId(long id) {

this.id = id;

}

public String getFname() {

return fname;

}

public void setFname(String fname) {

this.fname = fname;

}

public String getLname() {

return lname;

}

public void setLname(String lname) {

this.lname = lname;

}

public String getAddress() {

return address;

}

public void setAddress(String address) {

this.address = address;

}

public String getMobileNo() {

return mobileNo;

}

public void setMobileNo(String mobileNo) {

this.mobileNo = mobileNo;

}

public String getMailId() {

return mailId;

}

public void setMailId(String mailId) {

this.mailId = mailId;

}

public String getCity() {

return city;

}

public void setCity(String city) {

this.city = city;

}

public Timestamp getAddDate() {

return addDate;

}

public void setAddDate(Timestamp addDate) {

}

public String getDesignation() {

return designation;

}

public void setDesignation(String designation) {

this.designation = designation;

}

public Date getDob() {

return dob;

}

public void setDob(Date dob) {

this.dob = dob;

}

public Date getDoj() {

return doj;

}

public void setDoj(Date doj) {

this.doj = doj;

}

public BigDecimal getBasicSalary() {

return basicSalary;

}

public void setBasicSalary(BigDecimal basicSalary) {

this.basicSalary = basicSalary;

//calculating hra and PF

setHra(basicSalary.multiply(new BigDecimal("0.40")));

setProvidentFund(basicSalary.multiply(new BigDecimal("0.12")));

setGrossSalary(basicSalary.add(getHra().add(getProvidentFund())));

if (addDate == null) {

this.addDate = new Timestamp(System.currentTimeMillis());

} else {

this.addDate = addDate;

}

public BigDecimal getHra() {

return hra;

}

public void setHra(BigDecimal hra) {

this.hra = hra;

}

public BigDecimal getProvidentFund() {

return providentFund;

}

public void setProvidentFund(BigDecimal providentFund) {

this.providentFund = providentFund;

}

public BigDecimal getGrossSalary() {

return grossSalary;

}

public void setGrossSalary(BigDecimal grossSalary) {

this.grossSalary = grossSalary;

}

EmployeeMain.java

This class contain public static void main() (java main method) inside main tho objects of Employee class is created.

First object is created using parameterized constructor and object’s value is printer by overriding the toString() of Object class.

Second object is created using default constructor of employee and values are assigned using setter methods of class.

To print value of object getter method is used. Insted of using getter method toString() can also be used.

import java.math.BigDecimal;
import java.sql.Date;
import java.sql.Timestamp;

public class EmployeeMain {

    public static void main(String[] args) {
        /*initializing using constructor*/
        Employee employee = new Employee(1, "Ram", "Kumar", "Sector 5 bhilai", "345345345", "ram@test.com", "Bhilai", "Developer", Date.valueOf("1992-05-07"), Date.valueOf("2018-03-04"), new BigDecimal(450000), new Timestamp(System.currentTimeMillis()));
        System.out.println("Detail of employee");
        //printing employee using to string method of employee
        System.out.println(employee);
        //putting value using to getter of employee class
        Employee employee1 = new Employee();
        employee1.setId(2);
        employee1.setFname("Mohan");
        employee1.setLname("Singh");
        employee1.setAddress("Bhopal");
        employee1.setMobileNo("6523985623");
        employee1.setMailId("mohansingh@test.com");
        employee1.setCity("Bhopal");
        employee1.setDesignation("DBA");
        employee1.setDob(Date.valueOf("1992-03-01"));
        employee1.setDoj(Date.valueOf("2018-02-01"));
        employee1.setBasicSalary(new BigDecimal(40000));

        //shoing employee1 value using getter method
        System.out.println("Detail of employee1");
        System.out.println("id " + employee1.getId() + " fname " + employee1.getFname() + " lname " + employee1.getLname()
                + " address " + employee1.getAddress() + " mobileNo " + employee1.getMobileNo() + " mailId " + employee1.getMailId()
                + " city " + employee1.getCity() + " designation " + employee1.getDesignation() + " dob " + employee1.getDob()
                + " doj " + employee1.getDoj() + " salary " + employee1.getBasicSalary() + " hra " + employee1.getHra()
                + " PF " + employee1.getProvidentFund() + " Gross Salary " + employee1.getGrossSalary() + " addDate " + employee1.getAddDate());
    }

}

import java.math.BigDecimal;

import java.sql.Date;

import java.sql.Timestamp;

public class EmployeeMain {

public static void main(String[] args) {

/*initializing using constructor*/

Employee employee = new Employee(1, "Ram", "Kumar", "Sector 5 bhilai", "345345345", "[email protected]", "Bhilai", "Developer", Date.valueOf("1992-05-07"), Date.valueOf("2018-03-04"), new BigDecimal(450000), new Timestamp(System.currentTimeMillis()));

System.out.println("Detail of employee");

//printing employee using to string method of employee

System.out.println(employee);

//putting value using to getter of employee class

Employee employee1 = new Employee();

employee1.setId(2);

employee1.setFname("Mohan");

employee1.setLname("Singh");

employee1.setAddress("Bhopal");

employee1.setMobileNo("6523985623");

employee1.setMailId("[email protected]");

employee1.setCity("Bhopal");

employee1.setDesignation("DBA");

employee1.setDob(Date.valueOf("1992-03-01"));

employee1.setDoj(Date.valueOf("2018-02-01"));

employee1.setBasicSalary(new BigDecimal(40000));

//shoing employee1 value using getter method

System.out.println("Detail of employee1");

System.out.println("id " + employee1.getId() + " fname " + employee1.getFname() + " lname " + employee1.getLname()

+ " address " + employee1.getAddress() + " mobileNo " + employee1.getMobileNo() + " mailId " + employee1.getMailId()

+ " city " + employee1.getCity() + " designation " + employee1.getDesignation() + " dob " + employee1.getDob()

+ " doj " + employee1.getDoj() + " salary " + employee1.getBasicSalary() + " hra " + employee1.getHra()

+ " PF " + employee1.getProvidentFund() + " Gross Salary " + employee1.getGrossSalary() + " addDate " + employee1.getAddDate());

}

Its up to used which method he wants to use to set values in object.

Result of above program is

 Detail of employee
Employee{id=1, fname=Ram, lname=Kumar, address=Sector 5 bhilai, mobileNo=345345345, mailId=ram@test.com, city=Bhilai, designation=Developer, dob=1992-05-07, doj=2018-03-04, basicSalary=450000, hra=54000.00, providentFund=184500.00, grossSalary=688500.00, addDate=2020-08-03 15:58:37.466}
Detail of employee1
id 2 fname Mohan lname Singh address Bhopal mobileNo 6523985623 mailId mohansingh@test.com city Bhopal designation DBA dob 1992-03-01 doj 2018-02-01 salary 40000 hra 16000.00 PF 4800.00 Gross Salary 60800.00 addDate 2020-08-03 15:58:37.466

Detail of employee

Employee{id=1, fname=Ram, lname=Kumar, address=Sector 5 bhilai, mobileNo=345345345, mailId=ram@test.com, city=Bhilai, designation=Developer, dob=1992-05-07, doj=2018-03-04, basicSalary=450000, hra=54000.00, providentFund=184500.00, grossSalary=688500.00, addDate=2020-08-03 15:58:37.466}

Detail of employee1

id 2 fname Mohan lname Singh address Bhopal mobileNo 6523985623 mailId mohansingh@test.com city Bhopal designation DBA dob 1992-03-01 doj 2018-02-01 salary 40000 hra 16000.00 PF 4800.00 Gross Salary 60800.00 addDate 2020-08-03 15:58:37.466

If any one want to change value of any field then appropriate setter method needs to called

like want to update lname of employee object then use

employee.setLname("Verma");

this will assign new value to lname.

Learn database operations with employee details

Java program to swap two numbers

1 Swapping two numbers using third variable

public class SwapExample {
    public static void main(String[] args) {
        int a = 5, b = 7;
        int c;
        System.out.println("a= " + a + " b=" + b);
        c = a;
        a = b;
        b = c;
        System.out.println("a= " + a + " b=" + b);
   }
}

public class SwapExample {

public static void main(String[] args) {

int a = 5, b = 7;

int c;

System.out.println("a= " + a + " b=" + b);

c = a;

a = b;

b = c;

System.out.println("a= " + a + " b=" + b);

}

Output

a= 5 b=7
a= 7 b=5

1 2	a= 5 b=7 a= 7 b=5

2. Swapping two numbers without using third variable

public class SwapExample1 {
    public static void main(String[] args) {
        int a = 5, b = 7;
        int c;
        System.out.println("a= " + a + " b=" + b);
        a = a + b;
        b = a-b;
        a=a-b;
        System.out.println("a= " + a + " b=" + b);
    }
}

public class SwapExample1 {

public static void main(String[] args) {

int a = 5, b = 7;

int c;

System.out.println("a= " + a + " b=" + b);

a = a + b;

b = a-b;

a=a-b;

System.out.println("a= " + a + " b=" + b);

}

Output

a= 5 b=7
a= 7 b=5

1 2	a= 5 b=7 a= 7 b=5

3. Swapping two numbers in a single line using addition and subtraction

public class SwapExample1 {
    public static void main(String[] args) {
        int a = 5, b = 7;
        int c;
        System.out.println("a= " + a + " b=" + b);
        b = (a + b) - (a = b);
        System.out.println("a= " + a + " b=" + b);
    }
}

public class SwapExample1 {

public static void main(String[] args) {

int a = 5, b = 7;

int c;

System.out.println("a= " + a + " b=" + b);

b = (a + b) - (a = b);

System.out.println("a= " + a + " b=" + b);

}

Output

a= 5 b=7
a= 7 b=5

1 2	a= 5 b=7 a= 7 b=5

4. Swapping two numbers in a single line using multiplication and division

public class SwapExample1 {
    public static void main(String[] args) {
        int a = 5, b = 7;
        int c;
        System.out.println("a= " + a + " b=" + b);
         a = (a * b) / (b = a);
        System.out.println("a= " + a + " b=" + b);

    }
}

public class SwapExample1 {

public static void main(String[] args) {

int a = 5, b = 7;

int c;

System.out.println("a= " + a + " b=" + b);

a = (a * b) / (b = a);

System.out.println("a= " + a + " b=" + b);

}

Output

a= 5 b=7
a= 7 b=5

1 2	a= 5 b=7 a= 7 b=5

5. Swapping two numbers using multiplication and division

Here numbers must be non zero

public class SwapExample1 {
    public static void main(String[] args) {
        int a = 5, b = 7;
        int c;
        System.out.println("a= " + a + " b=" + b);
        a = a * b;
        b = a / b;
        a = a / b;
        System.out.println("a= " + a + " b=" + b);
    }
}

public class SwapExample1 {

public static void main(String[] args) {

int a = 5, b = 7;

int c;

System.out.println("a= " + a + " b=" + b);

a = a * b;

b = a / b;

a = a / b;

System.out.println("a= " + a + " b=" + b);

}

Output

a= 5 b=7
a= 7 b=5

1 2	a= 5 b=7 a= 7 b=5

6. Swapping two numbers using XOR operator

public class SwapExample1 {

    public static void main(String[] args) {
        int a = 5, b = 7;
        int c;
        System.out.println("a= " + a + " b=" + b);
        a = a ^ b;
        b = a ^ b;
        a = a ^ b;
        System.out.println("a= " + a + " b=" + b);

    }
}

public class SwapExample1 {

public static void main(String[] args) {

int a = 5, b = 7;

int c;

System.out.println("a= " + a + " b=" + b);

a = a ^ b;

b = a ^ b;

a = a ^ b;

System.out.println("a= " + a + " b=" + b);

}

above operation can also be written as

Output

        a ^= b;
        b ^= a;
        a ^= b;

a ^= b;

b ^= a;

a ^= b;

Output

a= 5 b=7
a= 7 b=5

1 2	a= 5 b=7 a= 7 b=5

Write a java program to reverse a string

Using StringBuffer or StringBuilder class

import java.util.Scanner;
public class ReverseString {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("Enter a String");
        String string = scanner.next();
        StringBuilder sb = new StringBuilder(string);
        String reverseString = sb.reverse().toString();
        System.out.println("Your String is " + string);
        System.out.println("Reverse String is " + reverseString);
    }
}

import java.util.Scanner;

public class ReverseString {

public static void main(String[] args) {

Scanner scanner = new Scanner(System.in);

System.out.println("Enter a String");

String string = scanner.next();

StringBuilder sb = new StringBuilder(string);

String reverseString = sb.reverse().toString();

System.out.println("Your String is " + string);

System.out.println("Reverse String is " + reverseString);

}

Output

Enter a String
Programming
Your String is Programming
Reverse String is gnimmargorP

Enter a String

Programming

Your String is Programming

Reverse String is gnimmargorP

Using Loops(Iteration)

Copy and reverse the string

import java.util.Scanner;
public class ReverseStringExample {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("Enter a String");
        String string = scanner.next();
        char[] c = string.toCharArray();
        char[] r = new char[c.length];
        int i = c.length - 1;
        int j = 0;
        while (i >= 0) {
            r[j] = c[i];
            i--;
            j++;
        }
        String reverseString = new String(r);
        System.out.println("String is " + string);
        System.out.println("Reverse string is " + reverseString);
    }
}

import java.util.Scanner;

public class ReverseStringExample {

public static void main(String[] args) {

Scanner scanner = new Scanner(System.in);

System.out.println("Enter a String");

String string = scanner.next();

char[] c = string.toCharArray();

char[] r = new char[c.length];

int i = c.length - 1;

int j = 0;

while (i >= 0) {

r[j] = c[i];

i--;

j++;

}

String reverseString = new String(r);

System.out.println("String is " + string);

System.out.println("Reverse string is " + reverseString);

}

Here getting input from user

converted into character array using toCharArray() of String

Initialize the other character array with same length as c character array.

Loop char array c in reverse order and r in forward order.

this will copy character array c in reverse order to r.

converted char array r to String

print both character array

Output

Enter a String
Java
String is Java
Reverse string is avaJ

Enter a String

Java

String is Java

Reverse string is avaJ

Even or odd program in java

The number which is divisible by 2 is known as even number and the number which is not divisible by 2 is odd number.

in programming we use % operator to check divisibility.

The % operator returns the remainder of division. If a number is completely divisible its remainder is 0.

So any number is completely divisible by 2 then its remainder is zero.

4%2,20%2,60%2 all return zero.

5%2,45%2,51%2 its remainder is non zero.

Even or odd number program in java using if else

public class EvenOdd {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("Enter a number");
        int number = scanner.nextInt();
        if (number % 2 == 0) {
            System.out.println(number + " is a even number");
        } else {
            System.out.println(number + " is a odd number");
        }
    }
}

public class EvenOdd {

public static void main(String[] args) {

Scanner scanner = new Scanner(System.in);

System.out.println("Enter a number");

int number = scanner.nextInt();

if (number % 2 == 0) {

System.out.println(number + " is a even number");

} else {

System.out.println(number + " is a odd number");

}

Scanner class is used to take input from standard input stream that is keyboard.

Then perform modulo operation with 2 if remainder is 0 than a even number else number is odd.

Output

Enter a number
10
10 is a even number

Enter a number

10 is a even number

Even or odd number program in java using switch case

import java.util.Scanner;

public class EvenOddSwitch {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("Enter a number");
        int number = scanner.nextInt();
        switch (number % 2) {
            case 0:
                System.out.println(number + " is a even number");
                break;
            default:
                System.out.println(number + " is a odd number");
        }
    }
}

import java.util.Scanner;

public class EvenOddSwitch {

public static void main(String[] args) {

Scanner scanner = new Scanner(System.in);

System.out.println("Enter a number");

int number = scanner.nextInt();

switch (number % 2) {

case 0:

System.out.println(number + " is a even number");

break;

default:

System.out.println(number + " is a odd number");

}

switch(number%2) returns 0 or non zero value. So there should be two case statement case 0 for even numbers and default for non zero numbers.

Output

Enter a number
15
15 is a odd number

Enter a number

15 is a odd number

Even or odd number program in java using ternary operator

import java.util.Scanner;

public class EvenOddTernaryOperator {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("Enter a number");
        int number = scanner.nextInt();
        String type=(number % 2==0) ? "even" : "odd";
        System.out.println(number+" is a "+type +" number");
    }
}

import java.util.Scanner;

public class EvenOddTernaryOperator {

public static void main(String[] args) {

Scanner scanner = new Scanner(System.in);

System.out.println("Enter a number");

int number = scanner.nextInt();

String type=(number % 2==0) ? "even" : "odd";

System.out.println(number+" is a "+type +" number");

}

Output

Enter a number
24
24 is a even number

Enter a number

24 is a even number

String reverse program in java

String Reverse using StringBuilder

public class MyClass {
    public static void main(String args[]) {
      StringBuilder sb=new StringBuilder("Hello");
       System.out.println("String is  " + sb);
      sb=sb.reverse();
      System.out.println("Reverse String is  " + sb);
    }
}

public class MyClass {

public static void main(String args[]) {

StringBuilder sb=new StringBuilder("Hello");

System.out.println("String is " + sb);

sb=sb.reverse();

System.out.println("Reverse String is " + sb);

}

Leap Year Program in Java

A Leap Year is a year which has 366 days. This year February is of 29 days. Leap years occurs in every four years.

A leap year has following constraints.

We can check in programming as below

A year is divisible by 400 then it is a leap year
A year is divisible by 4 and not divisible by 100 then the year is leap year

import java.util.Scanner;
public class MyClass {
    public static void main(String args[]) {
        System.out.println("Enter the year to check it is prime or not");
        Scanner scanner = new Scanner(System.in);
        int year = scanner.nextInt();
        if (year % 4 == 0) {
            if (year % 100 == 0) {
                if (year % 400 == 0) {
                    System.out.println("Year " + year + " is a leap year");
                } else {
                    System.out.println("Year " + year + " is not a leap year");
                }
            } else {
                System.out.println("Year " + year + " is a leap year");
            }
        } else {
            System.out.println("Year " + year + " is not a leap year");
        }
    }
}

import java.util.Scanner;

public class MyClass {

public static void main(String args[]) {

System.out.println("Enter the year to check it is prime or not");

Scanner scanner = new Scanner(System.in);

int year = scanner.nextInt();

if (year % 4 == 0) {

if (year % 100 == 0) {

if (year % 400 == 0) {

System.out.println("Year " + year + " is a leap year");

} else {

System.out.println("Year " + year + " is not a leap year");

}

} else {

System.out.println("Year " + year + " is a leap year");

}

} else {

System.out.println("Year " + year + " is not a leap year");

}

Enter the year to check it is prime or not
2020
Year 2020 is a leap year

Enter the year to check it is prime or not

2020

Year 2020 is a leap year

See another program

import java.util.Scanner;
public class LeapYearTest {
    public static void main(String args[]) {
        System.out.println("Enter the year to check it is prime or not");
        Scanner scanner = new Scanner(System.in);
        int year = scanner.nextInt();
        
        if ((year % 400 == 0) || ( ( year % 100 != 0) && (year % 4 == 0 ))){
             System.out.println("Year " + year + " is a leap year");
        }
       else {
            System.out.println("Year " + year + " is not a leap year");
        }
    }
}

import java.util.Scanner;

public class LeapYearTest {

public static void main(String args[]) {

System.out.println("Enter the year to check it is prime or not");

Scanner scanner = new Scanner(System.in);

int year = scanner.nextInt();

if ((year % 400 == 0) || ( ( year % 100 != 0) && (year % 4 == 0 ))){

System.out.println("Year " + year + " is a leap year");

}

else {

System.out.println("Year " + year + " is not a leap year");

}

Enter the year to check it is prime or not
2000
Year 2000 is a leap year

Enter the year to check it is prime or not

2000

Year 2000 is a leap year

MySql Jdbc Operations for beginner

Database connection with java is one of the essential feature of java, In java to connect with database we use java database connectivity(JDBC) programs.

JDBC is an Application Program Interface(API) that is used to interact with database and java program in database independent way.

So JDBC (full form Java Database Connectivity) code to interact with mysql, oracle database and with other database.

Here we used jdbc with mysql to connect it we need a mysql jdbc driver to connect mysql with java.

Here we will see a java jdbc project to perform all basic operations involved in Database interaction.

Using Employee details program in java using jdbc opetations.

Setting Up Project

JDBC project setup is in two part

create database
Write Java, Jdbc codes

Creating database

Create a database user name with password.
given all privileges to user.
created database and table for employee.

Above all details are set in following script.

Run this script before running java jdbc program

create table employee(
id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
fname varchar(100),
lname varchar(30),
address varchar(80),
mobile_no varchar(12),
email_id varchar(100),
city varchar(50),
designation varchar(20),
dob date,
doj date,
salary decimal(10,2),
add_date timestamp DEFAULT CURRENT_TIMESTAMP,
primary key(id),
unique key(mobile_no),
unique key(email_id)
)ENGINE=InnoDB DEFAULT CHARSET=utf8;

create table employee(

id bigint(20) unsigned NOT NULL AUTO_INCREMENT,

fname varchar(100),

lname varchar(30),

address varchar(80),

mobile_no varchar(12),

email_id varchar(100),

city varchar(50),

designation varchar(20),

dob date,

doj date,

salary decimal(10,2),

add_date timestamp DEFAULT CURRENT_TIMESTAMP,

primary key(id),

unique key(mobile_no),

unique key(email_id)

)ENGINE=InnoDB DEFAULT CHARSET=utf8;

Writing Java Jdbc Code

Create Java Bean
Creating Main class (Execution starts from here)
Create Action class
Create DAO class

Java Bean

A Java Bean is a simple java class, that holds all properties, getter setter methods and constructors of the class.

Java Bean for Employee class is given below

/* This class contains getter setter and constructor of class
 */
package pojo;

import java.sql.Timestamp;

/**
 *
 * @author Manish Sahu
 */
public class Employee {

    private long id;
    private String fname;
    private String lname;
    private String address;
    private String mobileNo;
    private String mailId;
    private String city;
    private Timestamp addDate;

    public Employee() {
    }

    public Employee(String fname, String lname, String address, String mobileNo, String mailId, String city) {
        this.fname = fname;
        this.lname = lname;
        this.address = address;
        this.mobileNo = mobileNo;
        this.mailId = mailId;
        this.city = city;
    }

    public Employee(long id, String fname, String lname, String address, String mobileNo, String mailId, String city) {
        this.id = id;
        this.fname = fname;
        this.lname = lname;
        this.address = address;
        this.mobileNo = mobileNo;
        this.mailId = mailId;
        this.city = city;
    }

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

    public String getFname() {
        return fname;
    }

    public void setFname(String fname) {
        this.fname = fname;
    }

    public String getLname() {
        return lname;
    }

    public void setLname(String lname) {
        this.lname = lname;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getMobileNo() {
        return mobileNo;
    }

    public void setMobileNo(String mobileNo) {
        this.mobileNo = mobileNo;
    }

    public String getMailId() {
        return mailId;
    }

    public void setMailId(String mailId) {
        this.mailId = mailId;
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public Timestamp getAddDate() {
        return addDate;
    }

    public void setAddDate(Timestamp addDate) {
        this.addDate = addDate;
    }

    @Override
    public String toString() {
        return "Employee{" + "id=" + id + ", fname=" + fname + ", lname=" + lname + ", address=" + address + ", mobileNo=" + mobileNo + ", mailId=" + mailId + ", city=" + city + ", addDate=" + addDate + '}';
    }

}

100

101

102

103

104

105

106

107

108

109

110

111

112

113

/* This class contains getter setter and constructor of class

package pojo;

import java.sql.Timestamp;

/**

* @author Manish Sahu

public class Employee {

private long id;

private String fname;

private String lname;

private String address;

private String mobileNo;

private String mailId;

private String city;

private Timestamp addDate;

public Employee() {

}

public Employee(String fname, String lname, String address, String mobileNo, String mailId, String city) {

this.fname = fname;

this.lname = lname;

this.address = address;

this.mobileNo = mobileNo;

this.mailId = mailId;

this.city = city;

}

public Employee(long id, String fname, String lname, String address, String mobileNo, String mailId, String city) {

this.id = id;

this.fname = fname;

this.lname = lname;

this.address = address;

this.mobileNo = mobileNo;

this.mailId = mailId;

this.city = city;

}

public long getId() {

return id;

}

public void setId(long id) {

this.id = id;

}

public String getFname() {

return fname;

}

public void setFname(String fname) {

this.fname = fname;

}

public String getLname() {

return lname;

}

public void setLname(String lname) {

this.lname = lname;

}

public String getAddress() {

return address;

}

public void setAddress(String address) {

this.address = address;

}

public String getMobileNo() {

return mobileNo;

}

public void setMobileNo(String mobileNo) {

this.mobileNo = mobileNo;

}

public String getMailId() {

return mailId;

}

public void setMailId(String mailId) {

this.mailId = mailId;

}

public String getCity() {

return city;

}

public void setCity(String city) {

this.city = city;

}

public Timestamp getAddDate() {

return addDate;

}

public void setAddDate(Timestamp addDate) {

this.addDate = addDate;

}

@Override

public String toString() {

return "Employee{" + "id=" + id + ", fname=" + fname + ", lname=" + lname + ", address=" + address + ", mobileNo=" + mobileNo + ", mailId=" + mailId + ", city=" + city + ", addDate=" + addDate + '}';

}

Create Main Class

Below is main class for running all java jdbc examples

Here you find various examples like to insert in table, to update table ,delete a recored from mysql table and select a specific or all record from table.

To run below code see all actions and operations in below table

Sr No	Operation and code	Action
1	ADD (1)	Add Employee records in database should be initialize only once. First time after creating database
2	UPDATE (2)	Update a record in table, based on primary key id
3	DELETE (3)	Insert a new record to table and delete it from database
4	FETCH BY ID (4)	Fetch a record from table based on id
5	FETCH BY EMAIL (5)	Fetch a record from table based on email
6	FETCH BY MOBILE NO (6)	Fetch a record from table based on mobile number
7	SEARCH BY NAME (7)	Fetch records from table based on Name
8	FETCH BY CITY (8)	Fetch records from table based on city name
9	FETCH BY SALARY RANGE (9)	Fetch records from table based on Salary Range
10	FETCH BY DOB (10)	Fetch records from table based on date of birth
11	FETCH BY DOJ RANGE (11)	Fetch records from table based on Date of Joining Range
12	FETCH ALL (12)	Fetch all records from table
13	EXIT (0)	EXIT FROM ALL OPERATION

package ebhor.start;

import com.sun.jndi.url.dns.dnsURLContext;
import ebhor.action.EmployeeAction;
import ebhor.model.Employee;
import java.math.BigDecimal;
import java.sql.Date;
import java.util.Scanner;

/**
 *
 * @author Manish Sahu
 */
public class MainClass {

    EmployeeAction action = new EmployeeAction();

    public static void main(String[] args) {
        String DbOperation = "EXIT(0), ADD(1), UPDATE(2), DELETE(3), FETCHBYID(4), FETCHBYEMAIL(5), FETCHBYMOBNO(6), FETCHBYNAME(7),"
                + "FETCHBYCITY(8), FETCHBYSALRANGE(9), FETCHBYDOB(10), FETCHBYDOJRANGE(11), FETCHALL(12)";

        MainClass mainclass = new MainClass();
        int value = 0;
        do {
            System.out.println("valid operations are");

            System.out.println(DbOperation);
            System.out.println("Enter valid operation number 0-12");
            Scanner scanner = new Scanner(System.in);
            value = scanner.nextInt();

            switch (value) {
                case 1:
                    mainclass.addEmployee();
                    mainclass.fetchAllEmployee();
                    break;
                case 2:
                    mainclass.updateEmployee();
                    mainclass.fetchAllEmployee();
                    break;
                case 3:
                    mainclass.deleteEmployee();
                    break;
                case 4:
                    mainclass.fetchEmployeeById();
                    break;
                case 5:
                    mainclass.fetchEmployeeByEmail();
                    break;
                case 6:
                    mainclass.fetchEmployeeByMobileNo();
                    break;
                case 7:
                    mainclass.searchEmployeeByName();
                    break;
                case 8:
                    mainclass.fetchEmployeeByCity();
                    break;
                case 9:
                    mainclass.fetchEmployeeBySalaryRange();
                    break;
                case 10:
                    mainclass.fetchEmployeeByDob();
                    break;
                case 11:
                    mainclass.fetchEmployeeByDOjRange();
                    break;
                case 12:
                    mainclass.fetchAllEmployee();
                    break;
                case 0:
                    System.out.println("Exiting code");
                    break;
                default:
                    System.out.println("Not a valid entry");
            }
        } while (value != 0);

    }

    public void addEmployee() {
        Employee employee1 = new Employee("Ram", "Kumar", "Street no 5 sector 5", "123456789", "te@gmail.com", "Bhilai", "CEO", Date.valueOf("1988-03-22"), Date.valueOf("2015-05-05"), new BigDecimal(150000));
        Employee employee2 = new Employee("Mohan", "Lal", "Near Super market", "234567891", "mohallal@gmail.com", "Indore", "Manager", Date.valueOf("1988-05-20"), Date.valueOf("2015-05-15"), new BigDecimal(130000));
        Employee employee3 = new Employee("Shyam", "Bajpayee", "Shanti Nagar", "345678912", "bajpayee.shyam@gmail.com", "Pune", "Manager", Date.valueOf("1989-06-10"), Date.valueOf("2016-06-22"), new BigDecimal(130000));
        Employee employee4 = new Employee("Rita", "Kapoor", "Near HAL Layout", "456789123", "ritakapoor@gmail.com", "Bangalore", "Analyst", Date.valueOf("1989-06-12"), Date.valueOf("2016-06-06"), new BigDecimal(120000));
        Employee employee5 = new Employee("Nita", "Rai", "Sundar Nagar", "567891234", "nitarai@gmail.com", "Raipur", "Analyst", Date.valueOf("1988-03-22"), Date.valueOf("2015-05-05"), new BigDecimal(120000));
        action.insert(employee1);
        action.insert(employee2);
        action.insert(employee3);
        action.insert(employee4);
        action.insert(employee5);
    }

    public void updateEmployee() {
        Employee employee1 = new Employee(1l, "Rameshwar", "Kumar", "Street no 5 sector 6", "4564563442", "test@gmail.com", "Bhilai", "CEO", Date.valueOf("1988-03-22"), Date.valueOf("2015-05-05"), new BigDecimal(150000));
        action.update(employee1);
    }

    public void deleteEmployee() {
        Employee employee6 = new Employee("Ramesh", "Kumar", "Sadar market", "345234237", "rameshkumar1@gmail.com", "Bhopal", "Manager", Date.valueOf("1989-12-20"), Date.valueOf("2015-05-15"), new BigDecimal(100000));
        action.insert(employee6);
        action.delete(6l);
    }

    public void fetchEmployeeById() {
        action.fetchById(2l);
    }

    public void fetchEmployeeByEmail() {
        action.fetchByEmailId("bajpayee.shyam@gmail.com");
    }

    public void fetchEmployeeByMobileNo() {
        action.fetchByMobileNo("6538659801");
    }

    public void searchEmployeeByName() {
        action.searchByName("Ram");
    }

    public void fetchEmployeeByCity() {
        action.fetchByCity("Pune");
    }

    public void fetchEmployeeBySalaryRange() {
        action.fetchBySalaryRange(new BigDecimal(100000), new BigDecimal(130000));
    }

    public void fetchEmployeeByDob() {
        action.fetchByDob(Date.valueOf("1988-03-22"));
    }

    public void fetchEmployeeByDOjRange() {
        action.fetchByRangeDoj(Date.valueOf("2015-05-05"), Date.valueOf("2016-06-06"));
    }

    public void fetchAllEmployee() {
        action.fetchAll();
    }

}

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

package ebhor.start;

import com.sun.jndi.url.dns.dnsURLContext;

import ebhor.action.EmployeeAction;

import ebhor.model.Employee;

import java.math.BigDecimal;

import java.sql.Date;

import java.util.Scanner;

/**

* @author Manish Sahu

public class MainClass {

EmployeeAction action = new EmployeeAction();

public static void main(String[] args) {

String DbOperation = "EXIT(0), ADD(1), UPDATE(2), DELETE(3), FETCHBYID(4), FETCHBYEMAIL(5), FETCHBYMOBNO(6), FETCHBYNAME(7),"

+ "FETCHBYCITY(8), FETCHBYSALRANGE(9), FETCHBYDOB(10), FETCHBYDOJRANGE(11), FETCHALL(12)";

MainClass mainclass = new MainClass();

int value = 0;

do {

System.out.println("valid operations are");

System.out.println(DbOperation);

System.out.println("Enter valid operation number 0-12");

Scanner scanner = new Scanner(System.in);

value = scanner.nextInt();

switch (value) {

case 1:

mainclass.addEmployee();

mainclass.fetchAllEmployee();

break;

case 2:

mainclass.updateEmployee();

mainclass.fetchAllEmployee();

break;

case 3:

mainclass.deleteEmployee();

break;

case 4:

mainclass.fetchEmployeeById();

break;

case 5:

mainclass.fetchEmployeeByEmail();

break;

case 6:

mainclass.fetchEmployeeByMobileNo();

break;

case 7:

mainclass.searchEmployeeByName();

break;

case 8:

mainclass.fetchEmployeeByCity();

break;

case 9:

mainclass.fetchEmployeeBySalaryRange();

break;

case 10:

mainclass.fetchEmployeeByDob();

break;

case 11:

mainclass.fetchEmployeeByDOjRange();

break;

case 12:

mainclass.fetchAllEmployee();

break;

case 0:

System.out.println("Exiting code");

break;

default:

System.out.println("Not a valid entry");

}

} while (value != 0);

}

public void addEmployee() {

Employee employee1 = new Employee("Ram", "Kumar", "Street no 5 sector 5", "123456789", "[email protected]", "Bhilai", "CEO", Date.valueOf("1988-03-22"), Date.valueOf("2015-05-05"), new BigDecimal(150000));

Employee employee2 = new Employee("Mohan", "Lal", "Near Super market", "234567891", "[email protected]", "Indore", "Manager", Date.valueOf("1988-05-20"), Date.valueOf("2015-05-15"), new BigDecimal(130000));

Employee employee3 = new Employee("Shyam", "Bajpayee", "Shanti Nagar", "345678912", "[email protected]", "Pune", "Manager", Date.valueOf("1989-06-10"), Date.valueOf("2016-06-22"), new BigDecimal(130000));

Employee employee4 = new Employee("Rita", "Kapoor", "Near HAL Layout", "456789123", "[email protected]", "Bangalore", "Analyst", Date.valueOf("1989-06-12"), Date.valueOf("2016-06-06"), new BigDecimal(120000));

Employee employee5 = new Employee("Nita", "Rai", "Sundar Nagar", "567891234", "[email protected]", "Raipur", "Analyst", Date.valueOf("1988-03-22"), Date.valueOf("2015-05-05"), new BigDecimal(120000));

action.insert(employee1);

action.insert(employee2);

action.insert(employee3);

action.insert(employee4);

action.insert(employee5);

}

public void updateEmployee() {

Employee employee1 = new Employee(1l, "Rameshwar", "Kumar", "Street no 5 sector 6", "4564563442", "[email protected]", "Bhilai", "CEO", Date.valueOf("1988-03-22"), Date.valueOf("2015-05-05"), new BigDecimal(150000));

action.update(employee1);

}

public void deleteEmployee() {

Employee employee6 = new Employee("Ramesh", "Kumar", "Sadar market", "345234237", "[email protected]", "Bhopal", "Manager", Date.valueOf("1989-12-20"), Date.valueOf("2015-05-15"), new BigDecimal(100000));

action.insert(employee6);

action.delete(6l);

}

public void fetchEmployeeById() {

action.fetchById(2l);

}

public void fetchEmployeeByEmail() {

action.fetchByEmailId("[email protected]");

}

public void fetchEmployeeByMobileNo() {

action.fetchByMobileNo("6538659801");

}

public void searchEmployeeByName() {

action.searchByName("Ram");

}

public void fetchEmployeeByCity() {

action.fetchByCity("Pune");

}

public void fetchEmployeeBySalaryRange() {

action.fetchBySalaryRange(new BigDecimal(100000), new BigDecimal(130000));

}

public void fetchEmployeeByDob() {

action.fetchByDob(Date.valueOf("1988-03-22"));

}

public void fetchEmployeeByDOjRange() {

action.fetchByRangeDoj(Date.valueOf("2015-05-05"), Date.valueOf("2016-06-06"));

}

public void fetchAllEmployee() {

action.fetchAll();

}

Create Action Class

Above class will call method of below action class

package ebhor.action;

import ebhor.dao.EmployeeDao;
import java.util.List;
import ebhor.model.Employee;
import java.math.BigDecimal;
import java.sql.Date;

/**
 * All data accept and manipulation should be done here
 *
 * @author Manish Sahu
 */
public class EmployeeAction {

    EmployeeDao dao = new EmployeeDao();
    int st;

    public void insert(Employee employee) {
        st = dao.insert(employee);
        if (st == 1) {
            System.out.println("Employee Inserted Successfully");
        } else if (st == -1) {
            System.out.println("Employee Already exists");
        } else {
            System.out.println("Unable to Insert Employee");
        }
    }

    public void update(Employee employee) {
        st = dao.update(employee);
        if (st == 1) {
            System.out.println("Employee Updated Successfully");
        } else {
            System.out.println("Unable to update Employee");
        }
    }

    public void delete(Long id) {
        st = dao.delete(id);
        if (st == 1) {
            System.out.println("Employee Deleted Successfully");
        } else {
            System.out.println("Unable to Delete Employee");
        }
    }

    public void fetchById(Long id) {
        Employee employee = dao.fetchById(id);
        System.out.println("Employee Details are :");
        System.out.println(employee);
    }

    public void fetchByEmailId(String emailId) {
        Employee employee = dao.fetchByEmailId(emailId);
        System.out.println("Employee Details are :");
        System.out.println(employee);
    }

    public void fetchByMobileNo(String mobileNo) {
        Employee employee = dao.fetchByMobileNo(mobileNo);
        System.out.println("Employee Details are :");
        System.out.println(employee);
    }

    public void searchByName(String name) {
        List<Employee> employeeList = dao.searchByName(name);
        System.out.println("Employee Details are :");
        for (Employee employee : employeeList) {
            System.out.println(employee);
        }
    }

    public void fetchByCity(String city) {
        List<Employee> employeeList = dao.fetchByCity(city);
        System.out.println("Employee Details are :");
        for (Employee employee : employeeList) {
            System.out.println(employee);
        }
    }

    public void fetchBySalaryRange(BigDecimal lowerSalary, BigDecimal higherSalary) {
        List<Employee> employeeList = dao.fetchBySalaryRange(lowerSalary, higherSalary);
        System.out.println("Employee Details are :");
        for (Employee employee : employeeList) {
            System.out.println(employee);
        }
    }

    public void fetchByDob(Date dob) {
        List<Employee> employeeList = dao.fetchByDob(dob);
        System.out.println("Employee Details are :");
        for (Employee employee : employeeList) {
            System.out.println(employee);
        }
    }

    public void fetchByRangeDoj(Date startDate, Date endDate) {
        List<Employee> employeeList = dao.fetchByRangeDoj(startDate,endDate);
        System.out.println("Employee Details are :");
        for (Employee employee : employeeList) {
            System.out.println(employee);
        }
    }

    public void fetchAll() {
        List<Employee> employeeList = dao.fetchAll();
        System.out.println("Employee Details are :");
        for (Employee employee : employeeList) {
            System.out.println(employee);
        }
    }

}

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

package ebhor.action;

import ebhor.dao.EmployeeDao;

import java.util.List;

import ebhor.model.Employee;

import java.math.BigDecimal;

import java.sql.Date;

/**

* All data accept and manipulation should be done here

* @author Manish Sahu

public class EmployeeAction {

EmployeeDao dao = new EmployeeDao();

int st;

public void insert(Employee employee) {

st = dao.insert(employee);

if (st == 1) {

System.out.println("Employee Inserted Successfully");

} else if (st == -1) {

System.out.println("Employee Already exists");

} else {

System.out.println("Unable to Insert Employee");

}

public void update(Employee employee) {

st = dao.update(employee);

if (st == 1) {

System.out.println("Employee Updated Successfully");

} else {

System.out.println("Unable to update Employee");

}

public void delete(Long id) {

st = dao.delete(id);

if (st == 1) {

System.out.println("Employee Deleted Successfully");

} else {

System.out.println("Unable to Delete Employee");

}

public void fetchById(Long id) {

Employee employee = dao.fetchById(id);

System.out.println("Employee Details are :");

System.out.println(employee);

}

public void fetchByEmailId(String emailId) {

Employee employee = dao.fetchByEmailId(emailId);

System.out.println("Employee Details are :");

System.out.println(employee);

}

public void fetchByMobileNo(String mobileNo) {

Employee employee = dao.fetchByMobileNo(mobileNo);

System.out.println("Employee Details are :");

System.out.println(employee);

}

public void searchByName(String name) {

List<Employee> employeeList = dao.searchByName(name);

System.out.println("Employee Details are :");

for (Employee employee : employeeList) {

System.out.println(employee);

}

public void fetchByCity(String city) {

List<Employee> employeeList = dao.fetchByCity(city);

System.out.println("Employee Details are :");

for (Employee employee : employeeList) {

System.out.println(employee);

}

public void fetchBySalaryRange(BigDecimal lowerSalary, BigDecimal higherSalary) {

List<Employee> employeeList = dao.fetchBySalaryRange(lowerSalary, higherSalary);

System.out.println("Employee Details are :");

for (Employee employee : employeeList) {

System.out.println(employee);

}

public void fetchByDob(Date dob) {

List<Employee> employeeList = dao.fetchByDob(dob);

System.out.println("Employee Details are :");

for (Employee employee : employeeList) {

System.out.println(employee);

}

public void fetchByRangeDoj(Date startDate, Date endDate) {

List<Employee> employeeList = dao.fetchByRangeDoj(startDate,endDate);

System.out.println("Employee Details are :");

for (Employee employee : employeeList) {

System.out.println(employee);

}

public void fetchAll() {

List<Employee> employeeList = dao.fetchAll();

System.out.println("Employee Details are :");

for (Employee employee : employeeList) {

System.out.println(employee);

}

Create DAO class

The above action class will call to below DAO class method

Here All JDBC Prepared statement are used to interact with mysql

Various JDBC operations used here are

Insert
Update
Delete
FetchById
FetchByEmailId
FetchByMobileNo
SearchByName
FetchByCity
FetchBySalaryRange
FetchByDob
FetchByDojRange
FetchAll

/*
 * All database operation create update delete and select 
 * of employee should be done here
 *
 */
package ebhor.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import ebhor.model.Employee;
import com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException;
import java.math.BigDecimal;
import java.sql.Date;

public class EmployeeDao {
    
    Connection con = null;
    PreparedStatement ps = null;
    ResultSet rs = null;
    int st;//status

     /*JDBC Insert method*/
    public int insert(Employee employee) {
        con = ConnectionFactory.getConnection();
        try {
            String query = "insert into employee(fname,lname,address,mobile_no,email_id,city,designation,dob,doj,salary) "
                    + "values(?,?,?,?,?,?,?,?,?,?)";
            ps = con.prepareStatement(query);
            ps.setString(1, employee.getFname());
            ps.setString(2, employee.getLname());
            ps.setString(3, employee.getAddress());
            ps.setString(4, employee.getMobileNo());
            ps.setString(5, employee.getMailId());
            ps.setString(6, employee.getCity());
            ps.setString(7, employee.getDesignation());
            ps.setDate(8, employee.getDob());
            ps.setDate(9, employee.getDoj());
            ps.setBigDecimal(10, employee.getSalary());
            st = ps.executeUpdate();
            System.out.println("inserted employee " + st);
        } catch (MySQLIntegrityConstraintViolationException e) {
            st = -1;
            e.printStackTrace();
        } catch (Exception e) {
            st = -2;
            e.printStackTrace();
        } finally {
            try {
                con.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
        return st;
    }
    
    /*JDBC Update method*/
     public int update(Employee employee) {
        con = ConnectionFactory.getConnection();
        try {
            String query = "update employee set fname=?,lname=?,address=?,mobile_no=?,email_id=?,city=?, "
                    + "designation=?,dob=?,doj=?,salary=? "
                    + "where id=? ";
            ps = con.prepareStatement(query);
            ps.setString(1, employee.getFname());
            ps.setString(2, employee.getLname());
            ps.setString(3, employee.getAddress());
            ps.setString(4, employee.getMobileNo());
            ps.setString(5, employee.getMailId());
            ps.setString(6, employee.getCity());
            ps.setString(7, employee.getDesignation());
            ps.setDate(8, employee.getDob());
            ps.setDate(9, employee.getDoj());
            ps.setBigDecimal(10, employee.getSalary());
            ps.setLong(11, employee.getId());
            st = ps.executeUpdate();
            System.out.println("updated employee " + st);
        } catch (Exception e) {
            st = -2;
            e.printStackTrace();
        } finally {
            try {
                con.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
        return st;
    }
    
   /*JDBC delete method*/
     public int delete(long id) {
        con = ConnectionFactory.getConnection();
        try {
            String query = "delete from employee where id=? ";
            ps = con.prepareStatement(query);
            ps.setLong(1, id);
            st = ps.executeUpdate();
            System.out.println("deleted employee " + st);
        } catch (Exception e) {
            st = -2;
            e.printStackTrace();
        } finally {
            try {
                con.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
        return st;
    }
    
   /*JDBC fetchById method*/
     public Employee fetchById(long id) {
        Employee employee = new Employee();
        con = ConnectionFactory.getConnection();
        try {
            String query = "select * from employee where id=?";
            ps = con.prepareStatement(query);
            ps.setLong(1, id);
            rs = ps.executeQuery();
            while (rs.next()) {
                employee.setId(rs.getLong("id"));
                employee.setFname(rs.getString("fname"));
                employee.setLname(rs.getString("lname"));
                employee.setAddress(rs.getString("address"));
                employee.setMobileNo(rs.getString("mobile_no"));
                employee.setMailId(rs.getString("email_id"));
                employee.setCity(rs.getString("city"));
                employee.setDesignation(rs.getString("designation"));
                employee.setDob(rs.getDate("dob"));
                employee.setDoj(rs.getDate("doj"));
                employee.setSalary(rs.getBigDecimal("salary"));
                employee.setAddDate(rs.getTimestamp("add_date"));
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                con.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
        return employee;
    }
    
    /*JDBC fetchByEmailId method*/
    public Employee fetchByEmailId(String emailId) {
        Employee employee = new Employee();
        con = ConnectionFactory.getConnection();
        try {
            String query = "select * from employee where email_id=?";
            ps = con.prepareStatement(query);
            ps.setString(1, emailId);
            rs = ps.executeQuery();
            while (rs.next()) {
                employee.setId(rs.getLong("id"));
                employee.setFname(rs.getString("fname"));
                employee.setLname(rs.getString("lname"));
                employee.setAddress(rs.getString("address"));
                employee.setMobileNo(rs.getString("mobile_no"));
                employee.setMailId(rs.getString("email_id"));
                employee.setCity(rs.getString("city"));
                employee.setDesignation(rs.getString("designation"));
                employee.setDob(rs.getDate("dob"));
                employee.setDoj(rs.getDate("doj"));
                employee.setSalary(rs.getBigDecimal("salary"));
                employee.setAddDate(rs.getTimestamp("add_date"));
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                con.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
        return employee;
    }
    
    /*JDBC fetchByMobileNo method*/
    public Employee fetchByMobileNo(String mobileNo) {
        Employee employee = new Employee();
        con = ConnectionFactory.getConnection();
        try {
            String query = "select * from employee where mobile_no=?";
            ps = con.prepareStatement(query);
            ps.setString(1, mobileNo);
            rs = ps.executeQuery();
            while (rs.next()) {
                employee.setId(rs.getLong("id"));
                employee.setFname(rs.getString("fname"));
                employee.setLname(rs.getString("lname"));
                employee.setAddress(rs.getString("address"));
                employee.setMobileNo(rs.getString("mobile_no"));
                employee.setMailId(rs.getString("email_id"));
                employee.setCity(rs.getString("city"));
                employee.setDesignation(rs.getString("designation"));
                employee.setDob(rs.getDate("dob"));
                employee.setDoj(rs.getDate("doj"));
                employee.setSalary(rs.getBigDecimal("salary"));
                employee.setAddDate(rs.getTimestamp("add_date"));
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                con.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
        return employee;
    }
    
      /*JDBC searchByName method*/
     public List<Employee> searchByName(String name) {
        List<Employee> employeeList = new ArrayList<Employee>();
        
        con = ConnectionFactory.getConnection();
        try {
            String query = "select * from employee where fname like ? or lname like ?";
            ps = con.prepareStatement(query);
            ps.setString(1, "%" + name + "%");
            ps.setString(2, "%" + name + "%");
            rs = ps.executeQuery();
            while (rs.next()) {
                Employee employee = new Employee();
                employee.setId(rs.getLong("id"));
                employee.setFname(rs.getString("fname"));
                employee.setLname(rs.getString("lname"));
                employee.setAddress(rs.getString("address"));
                employee.setMobileNo(rs.getString("mobile_no"));
                employee.setMailId(rs.getString("email_id"));
                employee.setCity(rs.getString("city"));
                employee.setDesignation(rs.getString("designation"));
                employee.setDob(rs.getDate("dob"));
                employee.setDoj(rs.getDate("doj"));
                employee.setSalary(rs.getBigDecimal("salary"));
                employee.setAddDate(rs.getTimestamp("add_date"));
                employeeList.add(employee);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                con.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
        return employeeList;
    }
    
    /*JDBC fetchByCity method*/
   public List<Employee> fetchByCity(String city) {
        List<Employee> employeeList = new ArrayList<Employee>();
        
        con = ConnectionFactory.getConnection();
        try {
            String query = "select * from employee where  city=?";
            ps = con.prepareStatement(query);
            ps.setString(1, city);
            rs = ps.executeQuery();
            while (rs.next()) {
                Employee employee = new Employee();
                employee.setId(rs.getLong("id"));
                employee.setFname(rs.getString("fname"));
                employee.setLname(rs.getString("lname"));
                employee.setAddress(rs.getString("address"));
                employee.setMobileNo(rs.getString("mobile_no"));
                employee.setMailId(rs.getString("email_id"));
                employee.setCity(rs.getString("city"));
                employee.setDesignation(rs.getString("designation"));
                employee.setDob(rs.getDate("dob"));
                employee.setDoj(rs.getDate("doj"));
                employee.setSalary(rs.getBigDecimal("salary"));
                employee.setAddDate(rs.getTimestamp("add_date"));
                employeeList.add(employee);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                con.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
        return employeeList;
    }
    
     /*JDBC fetchBySalaryRange method*/
      public List<Employee> fetchBySalaryRange(BigDecimal lowerSalary, BigDecimal higherSalary) {
        List<Employee> employeeList = new ArrayList<Employee>();
        
        con = ConnectionFactory.getConnection();
        try {
            String query = "select * from employee where salary between ? and ?";
            ps = con.prepareStatement(query);
            ps.setBigDecimal(1, lowerSalary);
            ps.setBigDecimal(2, higherSalary);
            rs = ps.executeQuery();
            while (rs.next()) {
                Employee employee = new Employee();
                employee.setId(rs.getLong("id"));
                employee.setFname(rs.getString("fname"));
                employee.setLname(rs.getString("lname"));
                employee.setAddress(rs.getString("address"));
                employee.setMobileNo(rs.getString("mobile_no"));
                employee.setMailId(rs.getString("email_id"));
                employee.setCity(rs.getString("city"));
                employee.setDesignation(rs.getString("designation"));
                employee.setDob(rs.getDate("dob"));
                employee.setDoj(rs.getDate("doj"));
                employee.setSalary(rs.getBigDecimal("salary"));
                employee.setAddDate(rs.getTimestamp("add_date"));
                employeeList.add(employee);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                con.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
        return employeeList;
    }
    
    /*JDBC fetchByDob method*/
    public List<Employee> fetchByDob(Date dob) {
        List<Employee> employeeList = new ArrayList<Employee>();
        
        con = ConnectionFactory.getConnection();
        try {
            String query = "select * from employee where dob=?";
            ps = con.prepareStatement(query);
            ps.setDate(1, dob);
            rs = ps.executeQuery();
            while (rs.next()) {
                Employee employee = new Employee();
                employee.setId(rs.getLong("id"));
                employee.setFname(rs.getString("fname"));
                employee.setLname(rs.getString("lname"));
                employee.setAddress(rs.getString("address"));
                employee.setMobileNo(rs.getString("mobile_no"));
                employee.setMailId(rs.getString("email_id"));
                employee.setCity(rs.getString("city"));
                employee.setDesignation(rs.getString("designation"));
                employee.setDob(rs.getDate("dob"));
                employee.setDoj(rs.getDate("doj"));
                employee.setSalary(rs.getBigDecimal("salary"));
                employee.setAddDate(rs.getTimestamp("add_date"));
                employeeList.add(employee);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                con.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
        return employeeList;
    }
    
      /*JDBC fetchByRangeDoj method*/
     public List<Employee> fetchByRangeDoj(Date startDate, Date endDate) {
        List<Employee> employeeList = new ArrayList<Employee>();
        
        con = ConnectionFactory.getConnection();
        try {
            String query = "select * from employee where doj between ? and ?";
            ps = con.prepareStatement(query);
            ps.setDate(1, startDate);
            ps.setDate(2, endDate);
            rs = ps.executeQuery();
            while (rs.next()) {
                Employee employee = new Employee();
                employee.setId(rs.getLong("id"));
                employee.setFname(rs.getString("fname"));
                employee.setLname(rs.getString("lname"));
                employee.setAddress(rs.getString("address"));
                employee.setMobileNo(rs.getString("mobile_no"));
                employee.setMailId(rs.getString("email_id"));
                employee.setCity(rs.getString("city"));
                employee.setDesignation(rs.getString("designation"));
                employee.setDob(rs.getDate("dob"));
                employee.setDoj(rs.getDate("doj"));
                employee.setSalary(rs.getBigDecimal("salary"));
                employee.setAddDate(rs.getTimestamp("add_date"));
                employeeList.add(employee);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                con.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
        return employeeList;
    }
    
     /*JDBC fetchAll method*/
        public List<Employee> fetchAll() {
        List<Employee> employeeList = new ArrayList<Employee>();
        
        con = ConnectionFactory.getConnection();
        try {
            String query = "select * from employee";
            ps = con.prepareStatement(query);
            rs = ps.executeQuery();
            while (rs.next()) {
                Employee employee = new Employee();
                employee.setId(rs.getLong("id"));
                employee.setFname(rs.getString("fname"));
                employee.setLname(rs.getString("lname"));
                employee.setAddress(rs.getString("address"));
                employee.setMobileNo(rs.getString("mobile_no"));
                employee.setMailId(rs.getString("email_id"));
                employee.setCity(rs.getString("city"));
                employee.setDesignation(rs.getString("designation"));
                employee.setDob(rs.getDate("dob"));
                employee.setDoj(rs.getDate("doj"));
                employee.setSalary(rs.getBigDecimal("salary"));
                employee.setAddDate(rs.getTimestamp("add_date"));
                employeeList.add(employee);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                con.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
        return employeeList;
    }
}

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

418

419

420

421

422

423

424

425

426

427

428

429

430

431

432

433

434

435

436

437

438

439

440

441

442

443

444

445

446

447

448

449

450

451

* All database operation create update delete and select

* of employee should be done here

package ebhor.dao;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.util.ArrayList;

import java.util.List;

import ebhor.model.Employee;

import com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException;

import java.math.BigDecimal;

import java.sql.Date;

public class EmployeeDao {

Connection con = null;

PreparedStatement ps = null;

ResultSet rs = null;

int st;//status

/*JDBC Insert method*/

public int insert(Employee employee) {

con = ConnectionFactory.getConnection();

try {

String query = "insert into employee(fname,lname,address,mobile_no,email_id,city,designation,dob,doj,salary) "

+ "values(?,?,?,?,?,?,?,?,?,?)";

ps = con.prepareStatement(query);

ps.setString(1, employee.getFname());

ps.setString(2, employee.getLname());

ps.setString(3, employee.getAddress());

ps.setString(4, employee.getMobileNo());

ps.setString(5, employee.getMailId());

ps.setString(6, employee.getCity());

ps.setString(7, employee.getDesignation());

ps.setDate(8, employee.getDob());

ps.setDate(9, employee.getDoj());

ps.setBigDecimal(10, employee.getSalary());

st = ps.executeUpdate();

System.out.println("inserted employee " + st);

} catch (MySQLIntegrityConstraintViolationException e) {

st = -1;

e.printStackTrace();

} catch (Exception e) {

st = -2;

e.printStackTrace();

} finally {

try {

con.close();

} catch (SQLException ex) {

ex.printStackTrace();

}

return st;

}

/*JDBC Update method*/

public int update(Employee employee) {

con = ConnectionFactory.getConnection();

try {

String query = "update employee set fname=?,lname=?,address=?,mobile_no=?,email_id=?,city=?, "

+ "designation=?,dob=?,doj=?,salary=? "

+ "where id=? ";

ps = con.prepareStatement(query);

ps.setString(1, employee.getFname());

ps.setString(2, employee.getLname());

ps.setString(3, employee.getAddress());

ps.setString(4, employee.getMobileNo());

ps.setString(5, employee.getMailId());

ps.setString(6, employee.getCity());

ps.setString(7, employee.getDesignation());

ps.setDate(8, employee.getDob());

ps.setDate(9, employee.getDoj());

ps.setBigDecimal(10, employee.getSalary());

ps.setLong(11, employee.getId());

st = ps.executeUpdate();

System.out.println("updated employee " + st);

} catch (Exception e) {

st = -2;

e.printStackTrace();

} finally {

try {

con.close();

} catch (SQLException ex) {

ex.printStackTrace();

}

return st;

}

/*JDBC delete method*/

public int delete(long id) {

con = ConnectionFactory.getConnection();

try {

String query = "delete from employee where id=? ";

ps = con.prepareStatement(query);

ps.setLong(1, id);

st = ps.executeUpdate();

System.out.println("deleted employee " + st);

} catch (Exception e) {

st = -2;

e.printStackTrace();

} finally {

try {

con.close();

} catch (SQLException ex) {

ex.printStackTrace();

}

return st;

}

/*JDBC fetchById method*/

public Employee fetchById(long id) {

Employee employee = new Employee();

con = ConnectionFactory.getConnection();

try {

String query = "select * from employee where id=?";

ps = con.prepareStatement(query);

ps.setLong(1, id);

rs = ps.executeQuery();

while (rs.next()) {

employee.setId(rs.getLong("id"));

employee.setFname(rs.getString("fname"));

employee.setLname(rs.getString("lname"));

employee.setAddress(rs.getString("address"));

employee.setMobileNo(rs.getString("mobile_no"));

employee.setMailId(rs.getString("email_id"));

employee.setCity(rs.getString("city"));

employee.setDesignation(rs.getString("designation"));

employee.setDob(rs.getDate("dob"));

employee.setDoj(rs.getDate("doj"));

employee.setSalary(rs.getBigDecimal("salary"));

employee.setAddDate(rs.getTimestamp("add_date"));

}

} catch (Exception e) {

e.printStackTrace();

} finally {

try {

con.close();

} catch (SQLException ex) {

ex.printStackTrace();

}

return employee;

}

/*JDBC fetchByEmailId method*/

public Employee fetchByEmailId(String emailId) {

Employee employee = new Employee();

con = ConnectionFactory.getConnection();

try {

String query = "select * from employee where email_id=?";

ps = con.prepareStatement(query);

ps.setString(1, emailId);

rs = ps.executeQuery();

while (rs.next()) {

employee.setId(rs.getLong("id"));

employee.setFname(rs.getString("fname"));

employee.setLname(rs.getString("lname"));

employee.setAddress(rs.getString("address"));

employee.setMobileNo(rs.getString("mobile_no"));

employee.setMailId(rs.getString("email_id"));

employee.setCity(rs.getString("city"));

employee.setDesignation(rs.getString("designation"));

employee.setDob(rs.getDate("dob"));

employee.setDoj(rs.getDate("doj"));

employee.setSalary(rs.getBigDecimal("salary"));

employee.setAddDate(rs.getTimestamp("add_date"));

}

} catch (Exception e) {

e.printStackTrace();

} finally {

try {

con.close();

} catch (SQLException ex) {

ex.printStackTrace();

}

return employee;

}

/*JDBC fetchByMobileNo method*/

public Employee fetchByMobileNo(String mobileNo) {

Employee employee = new Employee();

con = ConnectionFactory.getConnection();

try {

String query = "select * from employee where mobile_no=?";

ps = con.prepareStatement(query);

ps.setString(1, mobileNo);

rs = ps.executeQuery();

while (rs.next()) {

employee.setId(rs.getLong("id"));

employee.setFname(rs.getString("fname"));

employee.setLname(rs.getString("lname"));

employee.setAddress(rs.getString("address"));

employee.setMobileNo(rs.getString("mobile_no"));

employee.setMailId(rs.getString("email_id"));

employee.setCity(rs.getString("city"));

employee.setDesignation(rs.getString("designation"));

employee.setDob(rs.getDate("dob"));

employee.setDoj(rs.getDate("doj"));

employee.setSalary(rs.getBigDecimal("salary"));

employee.setAddDate(rs.getTimestamp("add_date"));

}

} catch (Exception e) {

e.printStackTrace();

} finally {

try {

con.close();

} catch (SQLException ex) {

ex.printStackTrace();

}

return employee;

}

/*JDBC searchByName method*/

public List<Employee> searchByName(String name) {

List<Employee> employeeList = new ArrayList<Employee>();

con = ConnectionFactory.getConnection();

try {

String query = "select * from employee where fname like ? or lname like ?";

ps = con.prepareStatement(query);

ps.setString(1, "%" + name + "%");

ps.setString(2, "%" + name + "%");

rs = ps.executeQuery();

while (rs.next()) {

Employee employee = new Employee();

employee.setId(rs.getLong("id"));

employee.setFname(rs.getString("fname"));

employee.setLname(rs.getString("lname"));

employee.setAddress(rs.getString("address"));

employee.setMobileNo(rs.getString("mobile_no"));

employee.setMailId(rs.getString("email_id"));

employee.setCity(rs.getString("city"));

employee.setDesignation(rs.getString("designation"));

employee.setDob(rs.getDate("dob"));

employee.setDoj(rs.getDate("doj"));

employee.setSalary(rs.getBigDecimal("salary"));

employee.setAddDate(rs.getTimestamp("add_date"));

employeeList.add(employee);

}

} catch (Exception e) {

e.printStackTrace();

} finally {

try {

con.close();

} catch (SQLException ex) {

ex.printStackTrace();

}

return employeeList;

}

/*JDBC fetchByCity method*/

public List<Employee> fetchByCity(String city) {

List<Employee> employeeList = new ArrayList<Employee>();

con = ConnectionFactory.getConnection();

try {

String query = "select * from employee where city=?";

ps = con.prepareStatement(query);

ps.setString(1, city);

rs = ps.executeQuery();

while (rs.next()) {

Employee employee = new Employee();

employee.setId(rs.getLong("id"));

employee.setFname(rs.getString("fname"));

employee.setLname(rs.getString("lname"));

employee.setAddress(rs.getString("address"));

employee.setMobileNo(rs.getString("mobile_no"));

employee.setMailId(rs.getString("email_id"));

employee.setCity(rs.getString("city"));

employee.setDesignation(rs.getString("designation"));

employee.setDob(rs.getDate("dob"));

employee.setDoj(rs.getDate("doj"));

employee.setSalary(rs.getBigDecimal("salary"));

employee.setAddDate(rs.getTimestamp("add_date"));

employeeList.add(employee);

}

} catch (Exception e) {

e.printStackTrace();

} finally {

try {

con.close();

} catch (SQLException ex) {

ex.printStackTrace();

}

return employeeList;

}

/*JDBC fetchBySalaryRange method*/

public List<Employee> fetchBySalaryRange(BigDecimal lowerSalary, BigDecimal higherSalary) {

List<Employee> employeeList = new ArrayList<Employee>();

con = ConnectionFactory.getConnection();

try {

String query = "select * from employee where salary between ? and ?";

ps = con.prepareStatement(query);

ps.setBigDecimal(1, lowerSalary);

ps.setBigDecimal(2, higherSalary);

rs = ps.executeQuery();

while (rs.next()) {

Employee employee = new Employee();

employee.setId(rs.getLong("id"));

employee.setFname(rs.getString("fname"));

employee.setLname(rs.getString("lname"));

employee.setAddress(rs.getString("address"));

employee.setMobileNo(rs.getString("mobile_no"));

employee.setMailId(rs.getString("email_id"));

employee.setCity(rs.getString("city"));

employee.setDesignation(rs.getString("designation"));

employee.setDob(rs.getDate("dob"));

employee.setDoj(rs.getDate("doj"));

employee.setSalary(rs.getBigDecimal("salary"));

employee.setAddDate(rs.getTimestamp("add_date"));

employeeList.add(employee);

}

} catch (Exception e) {

e.printStackTrace();

} finally {

try {

con.close();

} catch (SQLException ex) {

ex.printStackTrace();

}

return employeeList;

}

/*JDBC fetchByDob method*/

public List<Employee> fetchByDob(Date dob) {

List<Employee> employeeList = new ArrayList<Employee>();

con = ConnectionFactory.getConnection();

try {

String query = "select * from employee where dob=?";

ps = con.prepareStatement(query);

ps.setDate(1, dob);

rs = ps.executeQuery();

while (rs.next()) {

Employee employee = new Employee();

employee.setId(rs.getLong("id"));

employee.setFname(rs.getString("fname"));

employee.setLname(rs.getString("lname"));

employee.setAddress(rs.getString("address"));

employee.setMobileNo(rs.getString("mobile_no"));

employee.setMailId(rs.getString("email_id"));

employee.setCity(rs.getString("city"));

employee.setDesignation(rs.getString("designation"));

employee.setDob(rs.getDate("dob"));

employee.setDoj(rs.getDate("doj"));

employee.setSalary(rs.getBigDecimal("salary"));

employee.setAddDate(rs.getTimestamp("add_date"));

employeeList.add(employee);

}

} catch (Exception e) {

e.printStackTrace();

} finally {

try {

con.close();

} catch (SQLException ex) {

ex.printStackTrace();

}

return employeeList;

}

/*JDBC fetchByRangeDoj method*/

public List<Employee> fetchByRangeDoj(Date startDate, Date endDate) {

List<Employee> employeeList = new ArrayList<Employee>();

con = ConnectionFactory.getConnection();

try {

String query = "select * from employee where doj between ? and ?";

ps = con.prepareStatement(query);

ps.setDate(1, startDate);

ps.setDate(2, endDate);

rs = ps.executeQuery();

while (rs.next()) {

Employee employee = new Employee();

employee.setId(rs.getLong("id"));

employee.setFname(rs.getString("fname"));

employee.setLname(rs.getString("lname"));

employee.setAddress(rs.getString("address"));

employee.setMobileNo(rs.getString("mobile_no"));

employee.setMailId(rs.getString("email_id"));

employee.setCity(rs.getString("city"));

employee.setDesignation(rs.getString("designation"));

employee.setDob(rs.getDate("dob"));

employee.setDoj(rs.getDate("doj"));

employee.setSalary(rs.getBigDecimal("salary"));

employee.setAddDate(rs.getTimestamp("add_date"));

employeeList.add(employee);

}

} catch (Exception e) {

e.printStackTrace();

} finally {

try {

con.close();

} catch (SQLException ex) {

ex.printStackTrace();

}

return employeeList;

}

/*JDBC fetchAll method*/

public List<Employee> fetchAll() {

List<Employee> employeeList = new ArrayList<Employee>();

con = ConnectionFactory.getConnection();

try {

String query = "select * from employee";

ps = con.prepareStatement(query);

rs = ps.executeQuery();

while (rs.next()) {

Employee employee = new Employee();

employee.setId(rs.getLong("id"));

employee.setFname(rs.getString("fname"));

employee.setLname(rs.getString("lname"));

employee.setAddress(rs.getString("address"));

employee.setMobileNo(rs.getString("mobile_no"));

employee.setMailId(rs.getString("email_id"));

employee.setCity(rs.getString("city"));

employee.setDesignation(rs.getString("designation"));

employee.setDob(rs.getDate("dob"));

employee.setDoj(rs.getDate("doj"));

employee.setSalary(rs.getBigDecimal("salary"));

employee.setAddDate(rs.getTimestamp("add_date"));

employeeList.add(employee);

}

} catch (Exception e) {

e.printStackTrace();

} finally {

try {

con.close();

} catch (SQLException ex) {

ex.printStackTrace();

}

return employeeList;

}

Download this Java Project with source code for github

How to Convert Java Object to/from JSON using GSON

Gson is Java JSON library that is used to convert Java object to/from JSON

GSON is developed by google.

GSON Maven dependency is as below

<!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->
<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>2.8.5</version>
</dependency>

<groupId>com.google.code.gson</groupId>

</dependency>

You can also download Gson Jar from here

Gson jar contains API to work with JSON

GOal of GSON is provide simple methods to convert and receive JSON, Provides extensive support for Generics, support complex objects

GSON provides simple functions to convert in to JSON it has toJSON() and from JSON to Java Object it has fromJSON()

Creating JSON Object

1. Gson gson=new Gson();
2. GsonBuilder gsonBuilder = new GsonBuilder();
Gson gson1 = gsonBuilder.create();

Here Gson() is no argument constructor that will create Gson object.

Using GsonBuilder by calling create() we get Gson object

Converting Java to JSON value

package jsonpkg;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

public class GsonExample {

    public static void main(String[] args) {
        int a = 5;
        double d = 45.44;
        String name = "Rama";
        int[] age = {23, 22, 25, 26, 27, 30};
        double[] price = {34.33, 55.43, 51.33, 54.22, 77.00};
        List<String> names = new ArrayList<String>();
        names.add("Ram");
        names.add("Mohan");
        names.add("Sohan");

        Set<String> branch = new HashSet<String>();
        branch.add("Computer Science");
        branch.add("Electronics and TeleCommunications");
        branch.add("Civil Engg");
        Map map = new HashMap();
        map.put(1, "Computer");
        map.put(2, "Printer");
        map.put(3, "Scanner");

        Gson gson = new Gson();
        System.out.println("JSON of a =" + gson.toJson(a));
        System.out.println("JSON of d =" + gson.toJson(d));
        System.out.println("JSON of name =" + gson.toJson(name));
        System.out.println("JSON of age =" + gson.toJson(age));
        System.out.println("JSON of price =" + gson.toJson(price));
        GsonBuilder gsonBuilder = new GsonBuilder();
        Gson gson1 = gsonBuilder.create();
        System.out.println("JSON of names =" + gson1.toJson(names));
        System.out.println("JSON of branch =" + gson1.toJson(branch));

        System.out.println("JSON of map =" + gson1.toJson(map));
    }

}

package jsonpkg;

import com.google.gson.Gson;

import com.google.gson.GsonBuilder;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.HashSet;

import java.util.List;

import java.util.Map;

import java.util.Set;

public class GsonExample {

public static void main(String[] args) {

int a = 5;

double d = 45.44;

String name = "Rama";

int[] age = {23, 22, 25, 2