java Archives - Page 3 of 12

Displaying file properties

September 19, 2023September 19, 2023 by Manish Sahu

Displaying file properties can be easily done in java

package io;

import java.io.File;
import java.io.IOException;

public class FileOrDir {

    public static void main(String[] args) {
        File f = new File("D:\\first.txt");
        File f1 = new File("D:\\second.txt");
        if (f.exists() == false) {
            System.out.println("File  or Directory does not exists");
        }
        if (f.isDirectory()) {
            System.out.println("This is a directory");
        }
        if (f.isFile()) {
            System.out.println("This is a file");
            System.out.println("File name :" + f.getName());
            System.out.println("File path :" + f.getPath());
            System.out.println("File Absolute path :" + f.getAbsolutePath());
            try {
                System.out.println("File Canonical path :" + f.getCanonicalPath());
            } catch (IOException ex) {
                System.out.println("IOException " + ex);
            }
            System.out.println("File Parent :" + f.getParent());
            System.out.println("File can execute :" + f.canExecute());
            System.out.println("File can read :" + f.canRead());
            System.out.println("File can write :" + f.canWrite());
            System.out.println("File last Modified :" + f.lastModified());
            try {

                if (f1.createNewFile()) {
                    System.out.println("File created ");
                } else {
                    if (f1.exists()) {
                        System.out.println("File already exists ");
                        f1.delete();
                        System.out.println("File is get deleted ");
                        if (f1.createNewFile()) {
                            System.out.println("now File created ");
                        }
                    }
                }
            } catch (IOException ex) {
                System.out.println("IOException " + ex);
            }
            System.out.println("Setting the file readable status :" + f1.setReadable(true));
            System.out.println("Setting the file writable status :" + f1.setWritable(false));
            System.out.println("Can we write on file :" + f1.canWrite());
        }
    }
}

package io;

import java.io.File;

import java.io.IOException;

public class FileOrDir {

public static void main(String[] args) {

File f = new File("D:\\first.txt");

File f1 = new File("D:\\second.txt");

if (f.exists() == false) {

System.out.println("File or Directory does not exists");

}

if (f.isDirectory()) {

System.out.println("This is a directory");

}

if (f.isFile()) {

System.out.println("This is a file");

System.out.println("File name :" + f.getName());

System.out.println("File path :" + f.getPath());

System.out.println("File Absolute path :" + f.getAbsolutePath());

try {

System.out.println("File Canonical path :" + f.getCanonicalPath());

} catch (IOException ex) {

System.out.println("IOException " + ex);

}

System.out.println("File Parent :" + f.getParent());

System.out.println("File can execute :" + f.canExecute());

System.out.println("File can read :" + f.canRead());

System.out.println("File can write :" + f.canWrite());

System.out.println("File last Modified :" + f.lastModified());

try {

if (f1.createNewFile()) {

System.out.println("File created ");

} else {

if (f1.exists()) {

System.out.println("File already exists ");

f1.delete();

System.out.println("File is get deleted ");

if (f1.createNewFile()) {

System.out.println("now File created ");

}

} catch (IOException ex) {

System.out.println("IOException " + ex);

}

System.out.println("Setting the file readable status :" + f1.setReadable(true));

System.out.println("Setting the file writable status :" + f1.setWritable(false));

System.out.println("Can we write on file :" + f1.canWrite());

}

Overall, this program demonstrates how to work with files and directories in Java, including checking file properties, creating and deleting files, and setting file permissions. Q: Write a Java Program to read text file

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class ReadTextFile {
    public static void main(String[] args) {
        // Specify the path to the text file you want to read
        String filePath = "C:\\example\\file.txt"; // Replace with the actual file path

        try (BufferedReader br = new BufferedReader(new FileReader(filePath))) {
            String line;

            System.out.println("Contents of the text file:");

            // Read and print each line from the file
            while ((line = br.readLine()) != null) {
                System.out.println(line);
            }
        } catch (IOException e) {
            System.err.println("Error reading the file: " + e.getMessage());
        }
    }
}

import java.io.BufferedReader;

import java.io.FileReader;

import java.io.IOException;

public class ReadTextFile {

public static void main(String[] args) {

// Specify the path to the text file you want to read

String filePath = "C:\\example\\file.txt"; // Replace with the actual file path

try (BufferedReader br = new BufferedReader(new FileReader(filePath))) {

String line;

System.out.println("Contents of the text file:");

// Read and print each line from the file

while ((line = br.readLine()) != null) {

System.out.println(line);

}

} catch (IOException e) {

System.err.println("Error reading the file: " + e.getMessage());

}

Q: Write a Java Program to Excel file To read … Read more

Reading a text file in Java

August 26, 2023August 26, 2023 by Manish Sahu

package ebhor.io;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

public class FileReading {

    public static void main(String[] args) {
        String line;
        BufferedReader br=null;
        try {
            FileReader fr = new FileReader("D:\\first.txt");
            br = new BufferedReader(fr);
            while ((line = br.readLine()) != null) {
                System.out.println(line);
            }
        } catch (FileNotFoundException e) {
            System.out.println("File not found " + e);
        } catch (IOException e) {
            System.out.println("IO Error " + e);
        } finally {
            if (br != null) {
                try {
                    br.close();
                } catch (IOException ex) {
                    System.out.println("File not closed " + ex);
                }
            }
        }
    }

package ebhor.io;

import java.io.BufferedReader;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.IOException;

public class FileReading {

public static void main(String[] args) {

String line;

BufferedReader br=null;

try {

FileReader fr = new FileReader("D:\\first.txt");

br = new BufferedReader(fr);

while ((line = br.readLine()) != null) {

System.out.println(line);

}

} catch (FileNotFoundException e) {

System.out.println("File not found " + e);

} catch (IOException e) {

System.out.println("IO Error " + e);

} finally {

if (br != null) {

try {

br.close();

} catch (IOException ex) {

System.out.println("File not closed " + ex);

}

For reading a file we have to create a FileReader object. Then we create BufferedReader object of FileReader. If file not found FileReader constructor throws FileNotFoundException. If br.readLine() is not able to read source file it throws IOException.

Break Statement in Java

August 26, 2023August 26, 2023 by manish

Break statement can use in looping statement (for,while,do while) and also in switch case. Break statement is used to terminate the execution of the current loop or current switch. Break statement is also used to the execution of label. Break statement is used in two variation 1. Break 2. Break label 1. Break Example

public class LoopBreaker {
    public static void main(String[] s) {
        for (int i = 1; i &lt;= 10; i++) {
            System.out.println("value of i=" + i);
            if (i == 5) {
                 System.out.println("breaking this look for i=" + i);
                break;
            }
        }
        System.out.println("outside loop");
    }

}

public class LoopBreaker {

public static void main(String[] s) {

for (int i = 1; i <= 10; i++) {

System.out.println("value of i=" + i);

if (i == 5) {

System.out.println("breaking this look for i=" + i);

break;

}

System.out.println("outside loop");

}

Continue Statement in Java

August 26, 2023August 26, 2023 by manish

Continue statement can used with iteration statement (for,while,do while). In for statement continue transfer the control to updation of loop variable. In while and do while statement continue transfer control to condition of the loop. Example

public class ContinueStatement {

    public static void main(String[] s) {

        for (int i = 1; i &lt;= 10; i++) {

            if (i == 5) {
                continue;
            }
            System.out.println("value of i= " + i);
        }
        System.out.println("outside loop");
    }
}

public class ContinueStatement {

public static void main(String[] s) {

for (int i = 1; i <= 10; i++) {

if (i == 5) {

continue;

}

System.out.println("value of i= " + i);

}

System.out.println("outside loop");

}

When value of i is 5 then continue statement is executed and control is transferred to beginning of … Read more

How to remove special characters from a string in java

August 13, 2023August 13, 2023 by manish

Here we will see How to remove special characters from a string in java. Special characters are like & $ % @ ! < > etc that may occurs in string. To remove this we see programs how to remove special characters in java In Java String is a class that provides different constructors and … Read more

Login page in awt applet Java

August 13, 2023August 13, 2023 by manish

Creating Login page in awt applet is easy. Here we are not using any layout. Login page contains two label, one textfield , one password field and two buttons. Steps by step process to develop this program is as below Declare Label, JTextField, JPasswordField and Button Inside init() create object for JLabel, JTextField and JPasswordField … Read more

Method Overloading with examples in Java

July 22, 2023 by manish

what is method overloading in java? In Java programming, Defining two or more methods with the same name with different parameter list are called Method Overloading in Java. Like void add(int a,int b);void add(double a, double b);void add(String a,String b);int add(int a,int b,int c); In method overloading, the method return type may be different. The … Read more

What is Java Pi | Pi in Java | Math.PI Java Value and Example

July 22, 2023 by manish

Pi (π) is a well-known mathematical constant whose value is 22/7 or 3.14159265359. Programming languages also use this constant for mathematical calculation. Here we discuss PI with respect to the Java programming language. In Java PI is defined as a field in java.lang.Math class. It is defined as static double PI and described as The double value … Read more

JLabel in Java Swing with Method Constructors and Examples

July 22, 2023 by manish

JLabel in Java Swing is an object that is used to display text and images in a Frame. Jlabel uses to display information, show different messages, and make the frame interactive and readable. JLabel class declaration

public class JLabel
extends JComponent
implements SwingConstants, Accessible

public class JLabel

extends JComponent

implements SwingConstants, Accessible

JLabel extends JComponent and implements SwingConstants and Accessible Interfaces. JLabel Constructors Sr No Constructor and Description 1 JLabel() … Read more

Applet Life Cycle in Java with Example

July 22, 2023July 22, 2023 by manish

Applet in Java Applet in Java is a special Java program that are primarily used in a internet programming. Applet Life Cycle is very important to know in Java Applet Programming. As we have already seen how to run program from command prompt, but there were no GUI. To provide Graphical user interface(GUI) Java Applet … Read more