Iterate Array of JSON objects

Question

I am using org.json.simple library to construct JSONArray of JSONObject. So my structure looks like

c= [
  {
    "name":"test",
    "age":1
  },
  {
   "name":"test",
   "age":1
   }
]

To iterate the array in java, I tried

for (int i = 0; i < c.size(); i++) {
    JSONObject obj = (JSONObject) c.get(i);
    System.out.println(obj.get("name"));        
}

It printed null, but when tried to print the obj.toString, it prints the JSON string as expected.

I am using org.json.simple jar, so cannot use the methods defined org.json.JSONArray or org.json.JSONObject.

Any ideas to get the values from the object with their key?

Answer 1

Your code is absolutely correct, it works fine with org.json.simple:

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

public class JsonTest {
    public static void main(String[] args) throws ParseException {
        JSONArray c = (JSONArray) new JSONParser()
                .parse("[ { \"name\":\"test\", \"age\":1 }, "
                        + "{ \"name\":\"test\", \"age\":1 } ]");
        for (int i = 0; i < c.size(); i++) {
            JSONObject obj = (JSONObject) c.get(i);
            System.out.println(obj.get("name"));        
        }
    }
}

It outputs:

test
test

Check how input JSONArray was created. It's possible that there's something different inside it. For example, it's possible that you have non-printable character in key name, so you don't see it when using c.toString(), but obj.get("name") fails.