Sending json response from servlet using gson

Here we want to send json data response from servlet.
Here a link is available in jsp page on link click it is calling /jsonResponse url where JsonResponse’s doGet() method is get called.
To generate json response we are setting response.setContentType("application/json"); that is used to set response as application/json
In servlet student object is created with name gender mobile number and three subjects marks. After creating object we are converting objects to json using gson library.

Project Explorer

1284_expo

index.jsp

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>Json Example</title>
    </head>
    <body>
        <h1>Servlet Json Response Example</h1>
        <a href="jsonResponse">Get Json response from server</a>
    </body>
</html>

<%@page contentType="text/html" pageEncoding="UTF-8"%>

<!DOCTYPE html>

<html>

<head>

<title>Json Example</title>

</head>

<body>

<h1>Servlet Json Response Example</h1>

<a href="jsonResponse">Get Json response from server</a>

</body>

</html>

JsonResponse.java

package ebhor.servlet;

import com.google.gson.Gson;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashSet;
import java.util.Set;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet(urlPatterns = {"/jsonResponse"})
public class JsonResponse extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("application/json");
        response.setCharacterEncoding("utf-8");
        Student student = new Student(12, "Ram Kumar", "Male", "1234565678");
        Subject subject1 = new Subject(1, "Computer Fundamentals");
        Subject subject2 = new Subject(2, "Computer Graphics");
        Subject subject3 = new Subject(3, "Data Structures");
        Set subjects = new HashSet();
        subjects.add(subject1);
        subjects.add(subject2);
        subjects.add(subject3);
        student.setSubjects(subjects);
        Address address = new Address(1, "Street 23 NN West ", "Bhilai", "Chhattisgarh", "India");
        student.setAddress(address);
        Gson gson = new Gson();
        String jsonData = gson.toJson(student);
        PrintWriter out = response.getWriter();
        try {
            out.println(jsonData);
        } finally {
            out.close();
        }

    }
}

package ebhor.servlet;

import com.google.gson.Gson;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.HashSet;

import java.util.Set;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

@WebServlet(urlPatterns = {"/jsonResponse"})

public class JsonResponse extends HttpServlet {

@Override

protected void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

response.setContentType("application/json");

response.setCharacterEncoding("utf-8");

Student student = new Student(12, "Ram Kumar", "Male", "1234565678");

Subject subject1 = new Subject(1, "Computer Fundamentals");

Subject subject2 = new Subject(2, "Computer Graphics");

Subject subject3 = new Subject(3, "Data Structures");

Set subjects = new HashSet();

subjects.add(subject1);

subjects.add(subject2);

subjects.add(subject3);

student.setSubjects(subjects);

Address address = new Address(1, "Street 23 NN West ", "Bhilai", "Chhattisgarh", "India");

student.setAddress(address);

Gson gson = new Gson();

String jsonData = gson.toJson(student);

PrintWriter out = response.getWriter();

try {

out.println(jsonData);

} finally {

out.close();

}

Student.java

package ebhor.servlet;

import java.io.Serializable;
import java.util.Set;
import java.util.HashSet;

public class Student implements Serializable {

    private long id;
    private String name;
    private String gender;
    private Address address;
    private Set subjects = new HashSet(0);
    private String mobileNo;

    public Student() {
    }

    public Student(long id, String name, String gender, String mobileNo) {
        this.id = id;
        this.name = name;
        this.gender = gender;
        this.mobileNo = mobileNo;
    }

    public long getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public Address getAddress() {
        return address;
    }

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

    public Set getSubjects() {
        return subjects;
    }

    public void setSubjects(Set subjects) {
        this.subjects = subjects;
    }

    public String getMobileNo() {
        return mobileNo;
    }

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

}

package ebhor.servlet;

import java.io.Serializable;

import java.util.Set;

import java.util.HashSet;

public class Student implements Serializable {

private long id;

private String name;

private String gender;

private Address address;

private Set subjects = new HashSet(0);

private String mobileNo;

public Student() {

}

public Student(long id, String name, String gender, String mobileNo) {

this.id = id;

this.name = name;

this.gender = gender;

this.mobileNo = mobileNo;

}

public long getId() {

return id;

}

public void setId(long id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getGender() {

return gender;

}

public void setGender(String gender) {

this.gender = gender;

}

public Address getAddress() {

return address;

}

public void setAddress(Address address) {

this.address = address;

}

public Set getSubjects() {

return subjects;

}

public void setSubjects(Set subjects) {

this.subjects = subjects;

}

public String getMobileNo() {

return mobileNo;

}

public void setMobileNo(String mobileNo) {

this.mobileNo = mobileNo;

}

Subject.java

package ebhor.servlet;

import java.io.Serializable;

public class Subject implements Serializable {

    private long id;
    private String name;

    public Subject() {
    }

    public Subject(long id, String name) {
        this.id = id;
        this.name = name;
    }

    public long getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

}

package ebhor.servlet;

import java.io.Serializable;

public class Subject implements Serializable {

private long id;

private String name;

public Subject() {

}

public Subject(long id, String name) {

this.id = id;

this.name = name;

}

public long getId() {

return id;

}

public void setId(long id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

Address

package ebhor.servlet;

import java.io.Serializable;

public class Address implements Serializable{

    private long id;
    private String street;
    private String city;
    private String state;
    private String country;

    public Address() {
    }

    public Address(long id, String street, String city, String state, String country) {
        this.id = id;
        this.street = street;
        this.city = city;
        this.state = state;
        this.country = country;
    }

    public long getId() {
        return id;
    }

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

    public String getStreet() {
        return street;
    }

    public void setStreet(String street) {
        this.street = street;
    }

    public String getCity() {
        return city;
    }

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

    public String getState() {
        return state;
    }

    public void setState(String state) {
        this.state = state;
    }

    public String getCountry() {
        return country;
    }

    public void setCountry(String country) {
        this.country = country;
    }

}

package ebhor.servlet;

import java.io.Serializable;

public class Address implements Serializable{

private long id;

private String street;

private String city;

private String state;

private String country;

public Address() {

}

public Address(long id, String street, String city, String state, String country) {

this.id = id;

this.street = street;

this.city = city;

this.state = state;

this.country = country;

}

public long getId() {

return id;

}

public void setId(long id) {

this.id = id;

}

public String getStreet() {

return street;

}

public void setStreet(String street) {

this.street = street;

}

public String getCity() {

return city;

}

public void setCity(String city) {

this.city = city;

}

public String getState() {

return state;

}

public void setState(String state) {

this.state = state;

}

public String getCountry() {

return country;

}

public void setCountry(String country) {

this.country = country;

}

Result

1284_first

1284_second

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