How can I iterate JSON objects in Java programming language?

If you need to iterate over JSON objects in Java, you can do it using libraries like orgjson or Jackson. Here is how you can achieve it

1 Using orgjson Library

The orgjson library provides a simple way to work with JSON in Java

Example

import org.json.JSONObject;

public class JSONIterationExample {

    public static void main(String[] args) {

        String jsonString = "{"name":"John", "age":30, "city":"New York"}";

        JSONObject jsonObject = new JSONObject(jsonString);

        for (String key : jsonObject.keySet()) {

            System.out.println(key + ": " + jsonObject.get(key));

        }

    }

}

This method iterates over all keys in the JSON object

It prints both the key and its corresponding value

2 Using Jackson Library

The Jackson library is more powerful and widely used for JSON processing

Example

import com.fasterxml.jackson.databind.JsonNode;

import com.fasterxml.jackson.databind.ObjectMapper;

import java.util.Iterator;

public class JacksonJSONIteration {

    public static void main(String[] args) throws Exception {

        String jsonString = "{"name":"John", "age":30, "city":"New York"}";

        ObjectMapper objectMapper = new ObjectMapper();

        JsonNode jsonNode = objectMapper.readTree(jsonString);

        Iterator fieldNames = jsonNode.fieldNames();

        while (fieldNames.hasNext()) {

            String field = fieldNames.next();

            System.out.println(field + ": " + jsonNode.get(field));

        }

    }

}

This approach works well for complex JSON structures

ObjectMapper converts JSON into a tree model, making it easier to navigate

3 Final Thoughts

• Use orgjson for small and simple JSON parsing
  
• Use Jackson for large or complex JSON structures
  
• Always handle exceptions to avoid crashes