Generating a JSON array

Using Google GSON, it's quite simple:

JSONObject result = new JSONObject();
result.put("columnHeadersKeys", JSONObject.NULL);

JSONArray headers = new JSONArray();

JSONObject obj = new JSONObject();
obj.put("id", 1);
obj.put("name", "abcd");
headers.put(obj);

obj = new JSONObject();
obj.put("id", 2);
obj.put("name", "xyz");
headers.put(obj);

result.put("rowHeaders", headers);

JSONArray data = new JSONArray();

obj = new JSONObject();
obj.put("id", 1);
obj.put("rowId", "R1");
obj.put("status", "PASSED");
data.put(obj);

obj = new JSONObject();
obj.put("id", 2);
obj.put("rowId", "R2");
obj.put("status", "PASSED");
data.put(obj);

result.put("data", data);

String output = result.toString();

Note that the entire creation of the object can be chained in one statement - however I find it easier to read when it's split out.

Use the Jackson library.

A sample code from the tutorial:

ObjectMapper mapper = new ObjectMapper();

Map<String,Object> userData = new HashMap<String,Object>();
Map<String,String> nameStruct = new HashMap<String,String>();
nameStruct.put("first", "Joe");
nameStruct.put("last", "Sixpack");
userData.put("name", nameStruct);
userData.put("gender", "MALE");
userData.put("verified", Boolean.FALSE);
userData.put("userImage", "Rm9vYmFyIQ==");

mapper.writeValue(new File("user-modified.json"), userData);

You can do like this It works perfectly for me with this line Log.i("MainJSON", MainJSON.toString()); I have printed Created JSONObject

try{
        JSONObject jo1=new JSONObject();
        jo1.put("id",001);
        jo1.put("name","abcd");

        JSONObject jo2=new JSONObject();
        jo2.put("id",002);
        jo2.put("name","xyz");

        JSONArray jarr1=new JSONArray();
        jarr1.put(0, jo1);
        jarr1.put(1, jo2);

        JSONObject jo3=new JSONObject();
        jo3.put("id",0001);
        jo3.put("rowId","R1");
        jo3.put("status","PASSED");

        JSONObject jo4=new JSONObject();
        jo4.put("id",0002);
        jo4.put("rowId","R2");
        jo4.put("status","PASSED");

        JSONArray jarr2=new JSONArray();
        jarr2.put(0, jo3);
        jarr2.put(1, jo4);

        JSONObject MainDataObj=new JSONObject();
        MainDataObj.put("rowHeaders", jarr1);
        MainDataObj.put("data", jarr2);
        MainDataObj.put("columnHeaderKeys", "null");

        JSONObject MainJSON=new JSONObject();
        MainJSON.put("MainData", MainDataObj);

        Log.i("MainJSON", MainJSON.toString());
        }catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }

Take a look here. You will find many projects that will help you.

I would try JSONObject.java from Crockford's JSON for Java Github repository.

Simple usage :

JSONObject obj = new JSONObject()
    .put("MainData", new JSONObject()
        .put("columnHeaderKeys", null)
        .put("rowHeaders", new JSONArray()
            .put(new JSONObject()
                .put("id", "001")
                .put("name", "abc")
            )
            .put(new JSONObject()
                .put("id", "002")
                .put("rowId", "R1")
            // ...
        )
    );

Output string with :

String jsonString = obj.toString();

or write directly to file :

obj.write(new FileWriter(new File("/path/to/destination/file")));