JAVA JSONObject在数组（JSONArray）中添加新元素

Question

I need add an element into JSONArray, but the method “append” creates multiples arrays instead add one element.

What would be the simplest way ?

I created the following sample code with JUnit just for isolate my issue.

import org.codehaus.jettison.json.JSONArray;
import org.codehaus.jettison.json.JSONException;
import org.codehaus.jettison.json.JSONObject;
import org.junit.Before;
import org.junit.Test;

public class JettisonJSONOperations {

   JSONObject jsonObject = new JSONObject();

   @Before
   public void preCreateJsonObject (){

       try {

           jsonObject.put("groupName","administrators");

           JSONArray members = new JSONArray();
           members.put("edward");
           members.put("richard");
           members.put("john");

           jsonObject.put("members", members);

       } catch (JSONException e) {
           e.printStackTrace();
       }

       System.out.println(jsonObject.toString());
   }

   @Test
   public void addingElementToJSONArray (){

       try {

           jsonObject.append("members", "batman");

       } catch (JSONException e) {
           e.printStackTrace();
       }

       System.out.println(jsonObject.toString());
   }
}

Output:

{"groupName":"administrators","members":["edward","richard","john"]}
{"groupName":"administrators","members":[["edward","richard","john"],"batman"]}

Process finished with exit code 0

Answer 1

After reading a lot of comments about jettison issues, I decided to change Jettison JSONObject library to org.json.

From:

   <dependency>
        <groupId>org.codehaus.jettison</groupId>
        <artifactId>jettison</artifactId>
        <version>1.3.4</version>
    </dependency>

To:

    <dependency>
        <groupId>org.json</groupId>
        <artifactId>json</artifactId>
        <version>20131018</version>
    </dependency>

And good news it works perfectly :)

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.junit.Before;
import org.junit.Test;

public class ORGJSONOperations {

    JSONObject jsonObject = new JSONObject();

    @Before
    public void preCreateJsonObject (){

        try {

            jsonObject.put("groupName","administrators");

            JSONArray members = new JSONArray();
            members.put("edward");
            members.put("richard");
            members.put("john");

            jsonObject.put("members", members);

        } catch (JSONException e) {
            e.printStackTrace();
        }

        System.out.println(jsonObject.toString());
    }

    @Test
    public void addingElementToJSONArray (){

        try {

            jsonObject.append("members", "batman");

        } catch (JSONException e) {
            e.printStackTrace();
        }

        System.out.println(jsonObject.toString());
    }
}

Output:

{"groupName":"administrators","members":["edward","richard","john"]}
{"groupName":"administrators","members":["edward","richard","john","batman"]}

Process finished with exit code 0