Maven dependency -
<!-- 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>
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c:/Ankit/myJson.json >
{"empId":11,"name":"ankit","address":["Paris","London"],"birthDate":"Sep 2, 2018 12:59:30 PM"}
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Convert - JSON string to java object or JSON to java string
package com.ankit.json;
import java.io.FileReader;
import com.google.gson.Gson;
import com.google.gson.JsonElement;
public class ConvertJsonToJavaObject {
public static void main(String[] args) {
try {
Gson gson = new Gson();
// 1 - Convert JSON to JsonElement
JsonElement jsonElement = gson.fromJson(
"{\"empId\":11,\"name\":\"ankit\",\"address\":[\"Paris\",\"London\"],\"birthDate\":\"Sep 2, 2018 12:59:30 PM\"}",
JsonElement.class);
String jsonInString = gson.toJson(jsonElement); // Convert JsonElement to String
System.out.println("jsonInString = " + jsonInString);
//2 - JSON to java object
FileReader fileReader = new FileReader("c:/Ankit/myJson.json");
Employee emp = gson.fromJson(fileReader, Employee.class);
System.out.println("emp = "+emp);
} catch (Exception e) {
e.printStackTrace();
}
}
}
//output
/*
jsonInString = {"empId":11,"name":"ankit","address":["Paris","London"],"birthDate":"Sep 2, 2018 12:59:30 PM"}
emp = Employee [empId=11, name=ankit, address=[Paris, London], birthDate=Sun Sep 02 12:59:30 IST 2018]
*/
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Employee class
package com.ankit.json;
import java.util.Date;
import java.util.List;
public class Employee {
//Fields
private int empId;
private String name;
private List<String> address;
private Date birthDate;
public Employee() {
super();
}
public Employee(int empId, String name, List<String> address, Date birthDate) {
super();
this.empId = empId;
this.name = name;
this.address = address;
this.birthDate=birthDate;
}
@Override
public String toString() {
return "Employee [empId=" + empId + ", name=" + name + ", address=" + address + ", birthDate=" + birthDate + "]";
}
//Setter and getters
public int getEmpId() {
return empId;
}
public void setEmpId(int empId) {
this.empId = empId;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public List<String> getAddress() {
return address;
}
public void setAddress(List<String> address) {
this.address = address;
}
public Date getBirthDate() {
return birthDate;
}
public void setBirthDate(Date birthDate) {
this.birthDate = birthDate;
}
}
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Related links >
1. Jackson JSON -
We can use Jackson api for for processing JSON in java.
Jackson JSON examples
2. Java provides API (JSR 353) for Processing JSON (JSR 353).
It provides -
- Object Model API
- Streaming API
Java API for JSON processing examples >