Json Parser in java

This is an sime JSON parser that can be easily used and modified to your project.

JsonParser.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;

public class JsonParser {
    final String TAG = "JsonParser";
    static InputStream is = null;
    static JSONObject jObj = null;
    static String json = "";

    public JSONObject getJSONFromUrl(String url) {
        // make HTTP request
        try {
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(url);
            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();
            is = httpEntity.getContent();           
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        try {
            //BufferedReader reader = new BufferedReader(new InputStreamReader(is, "iso-8859-1"), 8);
            BufferedReader reader = new BufferedReader(new InputStreamReader(is, "UTF-8"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;

            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }

            is.close();
            json = sb.toString();

        } catch (Exception e) {
            Log.e(TAG, "Error converting result " + e.toString());
        }

        // try parse the string to a JSON object
        try {
            jObj = new JSONObject(json);
        } catch (JSONException e) {
            Log.e(TAG, "Error parsing data " + e.toString());
        }

        // return JSON String
        return jObj;
    }
}

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.util.Log;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // we will using AsyncTask during parsing 
        new AsyncTaskParseJson().execute();
    }

    // you can make this class as another java file so it will be separated from your main activity.
    public class AsyncTaskParseJson extends AsyncTask<String, String, String> {
        final String TAG = "AsyncTaskParseJson";

        // set your json string url here

        String yourJsonStringUrl = "http://mytest.com";

        // contacts JSONArray
        JSONArray dataJsonArr = null;

        @Override
        protected void onPreExecute() {}

        @Override
        protected String doInBackground(String... arg0) {
            try {
                // instantiate our json parser
                JsonParser jParser = new JsonParser();

                // get json string from url
                JSONObject json = jParser.getJSONFromUrl(yourJsonStringUrl);

                // get the array of users
                dataJsonArr = json.getJSONArray("Users");

                // loop through all users
                for (int i = 0; i < dataJsonArr.length(); i++) {
                    JSONObject c = dataJsonArr.getJSONObject(i);
                    // Storing each json item in variable
                    String firstname = c.getString("firstname");
                    String lastname = c.getString("lastname");
                    String username = c.getString("username");

                    // show the values in our logcat
                    Log.e(TAG, "firstname: " + firstname 
                            + ", lastname: " + lastname
                            + ", username: " + username);
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }
            return null;
        }

        @Override
        protected void onPostExecute(String strFromDoInBg) {}
    }
}

JSON using Thread

 /**
  * GetJsonFromUrlTask Class
  * @author user
  *
  */

 private static class GetJsonFromUrlTask extends AsyncTask<String, Void, String> {
     @Override
     protected String doInBackground(String... params) {
         String url = params[0];
         InputStream is = null;
         String json = "";

      // make HTTP request
         try {
             DefaultHttpClient httpClient = new DefaultHttpClient();
             HttpPost httpPost = new HttpPost(url);
             HttpResponse httpResponse = httpClient.execute(httpPost);
             HttpEntity httpEntity = httpResponse.getEntity();

             is = httpEntity.getContent();           
         } catch (UnsupportedEncodingException e) {
             e.printStackTrace();
             return null;
         } catch (ClientProtocolException e) {
             e.printStackTrace();
             return null;
         } catch (IOException e) {
             e.printStackTrace();
             return null;
         }

         try {
 
              //BufferedReader reader = new BufferedReader(new InputStreamReader(is, "iso-8859-1"), 8);
              BufferedReader reader = new BufferedReader(new InputStreamReader(is, "UTF-8"), 8);

             StringBuilder sb = new StringBuilder();
             String line = null;
             while ((line = reader.readLine()) != null) {
                 sb.append(line + "\n");
             }
             is.close();
             json = sb.toString();
         } catch (Exception e) {
             Log.e(TAG, "Error converting result " + e.toString());
         }
         return json;
     }
 }

 /**
  * ParseJsonTask Class
  * @author user
  *
  */

 private static class ParseJsonTask extends AsyncTask<String, Void, JSONObject> {

  public static JSONObject jObj = null;

     @Override
     protected JSONObject doInBackground(String... params) {

      String json = params[0];
         // try parse the string to a JSON object
         try {
             jObj = new JSONObject(json);
         } catch (JSONException e) {
             Log.e(TAG, "Error parsing data " + e.toString());
         }
         return jObj;
     }
 }