Sending and Parsing JSON Objects in Android [closed]

Answer 1

There are different open source libraries, which you can use for parsing json.

org.json :- If you want to read or write json then you can use this library. First create JsonObject :-

JSONObject jsonObj = new JSONObject(<jsonStr>);

Now, use this object to get your values :-

String id = jsonObj.getString("id");

You can see complete example here

Jackson databind :- If you want to bind and parse your json to particular POJO class, then you can use jackson-databind library, this will bind your json to POJO class :-

ObjectMapper mapper = new ObjectMapper();
post= mapper.readValue(json, Post.class);

You can see complete example here

Answer 2

you just need to import this

   import org.json.JSONObject;


  constructing the String that you want to send

 JSONObject param=new JSONObject();
 JSONObject post=new JSONObject();

im using two object because you can have an jsonObject within another

post.put("username(here i write the key)","someusername"(here i put the value);
post.put("message","this is a sweet message");
post.put("image","http://localhost/someimage.jpg");
post.put("time":  "present time");

then i put the post json inside another like this

  param.put("post",post);

this is the method that i use to make a request

 makeRequest(param.toString());

public JSONObject makeRequest(String param)
{
    try
    {

setting the connection

        urlConnection = new URL("your url");
        connection = (HttpURLConnection) urlConnection.openConnection();
        connection.setDoOutput(true);
        connection.setRequestMethod("POST");
        connection.setRequestProperty("Content-type", "application/json;charset=UTF-8");
        connection.setReadTimeout(60000);
        connection.setConnectTimeout(60000);
        connection.connect();

setting the outputstream

        dataOutputStream = new DataOutputStream(connection.getOutputStream());

i use this to see in the logcat what i am sending

        Log.d("OUTPUT STREAM  " ,param);
        dataOutputStream.writeBytes(param);
        dataOutputStream.flush();
        dataOutputStream.close();

        InputStream in = new BufferedInputStream(connection.getInputStream());
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));
        result = new StringBuilder();
        String line;

here the string is constructed

        while ((line = reader.readLine()) != null)
        {
            result.append(line);
        }

i use this log to see what its comming in the response

         Log.d("INPUTSTREAM: ",result.toString());

instancing a json with the String that contains the server response

        jResponse=new JSONObject(result.toString());

    }
    catch (IOException e) {
        e.printStackTrace();
        return jResponse=null;
    } catch (JSONException e)
    {
        e.printStackTrace();
        return jResponse=null;
    }
    connection.disconnect();
    return jResponse;
}

Answer 3

I am surprised these have not been mentioned: but instead of using bare-bones rather manual process with json.org's little package, GSon and Jackson are much more convenient to use. So:

• GSON
• Jackson

So you can actually bind to your own POJOs, not some half-assed tree nodes or Lists and Maps. (and at least Jackson allows binding to such things too (perhaps GSON as well, not sure), JsonNode, Map, List, if you really want these instead of 'real' objects)

EDIT 19-MAR-2014:

Another new contender is Jackson jr library: it uses same fast Streaming parser/generator as Jackson (jackson-core), but data-binding part is tiny (50kB). Functionality is more limited (no annotations, just regular Java Beans), but performance-wise should be fast, and initialization (first-call) overhead very low as well. So it just might be good choice, especially for smaller apps.

Answer 4

if your are looking for fast json parsing in android than i suggest you a tool which is freely available.

JSON Class Creator tool

It's free to use and it's create your all json parsing class within a one-two seconds.. :D

Answer 5

There's not really anything to JSON. Curly brackets are for "objects" (associative arrays) and square brackets are for arrays without keys (numerically indexed). As far as working with it in Android, there are ready made classes for that included in the sdk (no download required).

Check out these classes: http://developer.android.com/reference/org/json/package-summary.html

Answer 6

Although there are already excellent answers are provided by users such as encouraging use of GSON etc. I would like to suggest use of org.json. It includes most of GSON functionalities. It also allows you to pass json string as an argument to it's JSONObject and it will take care of rest e.g:

JSONObject json = new JSONObject("some random json string");

This functionality make it my personal favorite.