How to iterate or loop through JSON array in Java
In this tutorial, we will learn how to iterate a JSON array in Java with the code and Explanation using json-simple-1.1.1.jar.
What is a JSON array?
- It represents a list of ordered values.
- Stores several values separated with commas (,).
- It stores the number, string, boolean, or object.
- [] (square bracket) represents JSON Array.
Prerequisite
You have to download json-simple-1.1.1.jar Version 1.1.1 from here.
Click here to directly download json-simple-1.1.1.jar
After download, the json-simple-1.1.1.jar add the .jar file to your IDE. Example NetBeans, etc.
A simple JSON file as an example
Here we already have a Detail.json file that contains an array of names.
Detail.json
{ "Names": [ "Aman", "Namita", "Piyush", "Priyansh", "kartik", "Adarsh" ] }
Java program to iterate or loop through JSON array
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 IterateJsonExample { public static void main(String[] args) { JSONParser jsonParserObj = new JSONParser(); try { JSONObject jsonObj = (JSONObject) jsonParserObj.parse(new FileReader("E://Detail.json")); System.out.println("Names are : "); JSONArray jsonArrObj = (JSONArray) jsonObj.get("Names"); Iterator<String> iteratorObj = jsonArrObj.iterator(); while (iteratorObj.hasNext()) { System.out.println(iteratorObj.next()); } } catch (FileNotFoundException ex) { ex.printStackTrace(); } catch (IOException ex) { ex.printStackTrace(); } catch (ParseException ex) { ex.printStackTrace(); } } }
Output:
Names are : Aman Namita Piyush Priyansh kartik Adarsh
Explanation
- Line 13: Here we created an object named jsonParserObj of JSONParser class to read the JSON file.
- Line 15: In try block,we using the jsonParserObj.parse() method and the FileReader class we read the JSON file and store it in jsonObj of the JSONObject.
- Line 18: Using the jsonObj.get() method, we get our array of names and stores in the JSONArray object known as jsonArrObj.
- Line 20 – 23: By using the jsonArrObj.iterator() method we store the values of jsonArrObj and in a while loop using the iteratorObj.next() that returns the value and simply we print that values.
That’s enough for an overview of how to iterate or loop through JSON array.
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