Android : JSONParser class with simple JSON parsing example

Step 1  : Simple JSON format :

{

  "contacts": [
        {
                "id": "c200",
                "name": "Ravi Tamada",
                "email": "umesh@gmail.com",
                "address": "xx-xx-xxxx,x - street, x - country",
                "gender" : "male",
                "phone": {
                    "mobile": "+91 0000000000",
                    "home": "00 000000",
                    "office": "00 000000"
                }
        },
        {
                "id": "c201",
                "name": "Johnny Depp",
                "email": "suryawanshi@gmail.com",
                "address": "xx-xx-xxxx,x - street, x - country",
                "gender" : "male",
                "phone": {
                    "mobile": "+91 0000000000",
                    "home": "00 000000",
                    "office": "00 000000"
                }
        },
/
/
/
/
so on...

Step 2 : Hello guys, this is comman JSONParser class.  Use this code and parse any    JSON.  Just put this java file in your package.

package com.umesh.jsonparse;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 {

    static InputStream is = null;
    static JSONObject jObj = null;
    static String json = "";

    // constructor
    public JSONParser() {

    }

    public JSONObject getJSONFromUrl(String url) {

        // Making HTTP request
        try {
            // defaultHttpClient
            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);
            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("Buffer Error", "Error converting result " + e.toString());
        }

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

        // return JSON String        return jObj;

    }
}

Step 3 : This is simple  class which parse JSON and show values in listiview.

Main.java :

import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.os.Bundle;
import android.app.Activity;
import android.app.ListActivity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.view.Menu;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;

public class Main extends ListActivity {
 private static String url="http://api.androidhive.info/contacts/";
 ArrayList<HashMap<String, String>> contactList;
 JSONArray contacts=null;

 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);

  //setContentView(R.layout.main);

  contactList=new ArrayList<HashMap<String,String>>();
  JSONParser jparse=new JSONParser();
  JSONObject jobject=jparse.getJSONFromUrl(url);

  try
  {
   contacts=jobject.getJSONArray("contacts");
 
   for(int i=0;i<contacts.length();i++)
   {
    HashMap<String,String> map=new HashMap<String, String>();
  
    JSONObject c=contacts.getJSONObject(i);
  
    map.put("id",c.getString("id"));
    map.put("name",c.getString("name"));
    map.put("email",c.getString("email"));
  
    JSONObject phone=c.getJSONObject("phone");
    map.put("phone",phone.getString("mobile"));
    contactList.add(map);
  
  
   }
  }
  catch(Exception e)
  {
   e.printStackTrace();
  }

  ListAdapter adapter=new SimpleAdapter(this,contactList,R.layout.listitems,new String[]{"name","email","phone"},new int []{R.id.tv_name,R.id.tv_email,R.id.tv_mobile});
  setListAdapter(adapter);

 }
}

Step 4 : As we are extending ListActivity, no need to use main layout with list view. Just define listitems. Following is the simple listitem layout

listitems.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="match_parent"
    tools:context=".Main" >
    <TextView
        android:id="@+id/tv_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Name"
        android:textSize="16dp"
        android:textAppearance="?android:attr/textAppearanceLarge" />
    <TextView
        android:id="@+id/tv_email"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/tv_name"
        android:text="email id"
        android:textSize="14dp"
        android:textAppearance="?android:attr/textAppearanceMedium" />
    <TextView
        android:id="@+id/tv_mobile"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/tv_email"
        android:text="Mobile : "
        android:textSize="14dp"
        android:textAppearance="?android:attr/textAppearanceMedium" />
    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/tv_mobile"
        android:src="@drawable/ic_launcher" />
</RelativeLayout>