How to parse nested JSON object in Java

By Atul Rai | Last Updated: July 14, 2020 Previous       Next

In this Java tutorial, we are going to parse or read the nested JSON object using the library JSON.simple. To parse the Nested Object, we need to create the object of parent object first.

{
  "name": "Mukul Sharma",
  "website": "www.websparrow.org",
  "technology": {
    "java": 8
  },
  "compose": {
    "total": 1,   
    "soundex": [
      {  
        "info": {
          "date_of_birth": "22-10-2016",
          "name_id": "ttr876"                   
        }
      }
    ]
  }
}

Above JSON file simply explain that there an object inside an object.

Check the full example

package org.websparrow;

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.Iterator;

import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

public class JsonNestedParseExample {

	public static void main(String[] args) {

		JSONParser jsonParser = new JSONParser();
		Object object;

		try {

			object = jsonParser.parse(new FileReader("nestedobjects.json"));
			JSONObject jsonObject = (JSONObject) object;

			String name = (String) jsonObject.get("name");
			System.out.println("Name: " + name);

			String website = (String) jsonObject.get("website");
			System.out.println("Website: " + website);

			JSONObject technology = (JSONObject) jsonObject.get("technology");
			System.out.println("Technology: " + technology);
			long java = (Long) technology.get("java");
			System.out.println("\tjava: " + java);

			JSONObject compose = (JSONObject) jsonObject.get("compose");
			System.out.println("compose: " + compose);
			long total = (Long) compose.get("total");
			System.out.println("\ttotal: " + total);
			JSONArray soundex = (JSONArray) compose.get("soundex");
			System.out.println("\tsoundex: " + soundex);

			Object composeObj = jsonObject.get("compose");
			JSONObject jsonObject1 = (JSONObject) composeObj;
			Iterator itr = soundex.iterator();

			while (itr.hasNext()) {

				Object slide = itr.next();
				JSONObject jsonObject2 = (JSONObject) slide;
				JSONObject info = (JSONObject) jsonObject2.get("info");

				String date_of_birth = (String) info.get("date_of_birth");
				String name_id = (String) info.get("name_id");

				System.out.println("\t\tDate of Birth: " + date_of_birth);
				System.out.println("\t\tName Id: " + name_id);
			}
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} catch (ParseException e) {
			e.printStackTrace();
		}
	}
}

Output:

Name: Mukul Sharma
Website: www.websparrow.org
Technology: {"java":8}
	java: 8
compose: {"total":1,"soundex":[{"info":{"date_of_birth":"22-10-2016","name_id":"ttr876"}}]}
	total: 1
	soundex: [{"info":{"date_of_birth":"22-10-2016","name_id":"ttr876"}}]
		Date of Birth: 22-10-2016
		Name Id: ttr876