Gson is a Java library that can be used to convert a JSON string to an equivalent Java object. Gson can work with arbitrary Java objects including pre-existing objects whose source code we don’t have. It provides the support to transfer data in between different programming languages modules.
JSON String Representation: The string must be in JSON format which is the name pair value.
jsonString = "{ gfgId : 10001, username : 'Jack jon', gender : 'M' }";
Conversion of JSON String into JSON Object
To convert the above JSON string into an object user must-have class with the same property (same name).
// creating object of Gson Gson gson = new Gson(); // calling method fromJson and passing JSON string into object // The first parameter is JSON string // The second parameter is the Java class to parse the JSON into an instance of. object = gson.fromJson(jsonString,GFG.class);
For more clarification follow the below example, to convert JSON String into JSON Object.
Example:
Java
// Java Program to demonstrate the // conversion of String to JSON object import com.google.gson.*; class GFG { int gfgId; String username; char gender; public GFG() { this.gfgId = 0; this.username = ""; this.gender = ' '; }} public class GFGMain { public static void main(String arg[]) { GFG gfg = null; // creating JSON String of GFG class object String jsonString; jsonString = "{"; jsonString += "gfgId : 10001,"; jsonString += "username : 'Jack jon',"; jsonString += "gender : 'M'"; jsonString += "}"; // creating object of gson Gson gson = new Gson(); // converting jsonStrig into object gfg = gson.fromJson(jsonString, GFG.class); System.out.println("GFG id of User : " + gfg.gfgId); System.out.println("Username : " + gfg.username); System.out.println("Gender : " + gfg.gender); }} |
Output:
