Android PHP JSON tutorial

Here I'm going to demonstrate how we can decode JSON encoded data in Android using very simple example. I used Android 2.2 for this.

First here is some extra information about JSON:

1. What is JSON

• JSON stands for JavaScript Object Notation
• JSON is lightweight text-data interchange format
• JSON is language independent 
• JSON is "self-describing" and easy to understand
                                                         (from w3schools)  

2. Click here to know benefits of JSON over XML

Now let's see simple example of JSON reading in Android.
In my project there is a PHP web service which encodes a string array in to JSON format. I'm going to access that web service using Android http client and then it decodes json data. I have tested this on Android 2.2

1. Here is the code for PHP

<?php
$data = array('name' => 'Froyo', 'version' => 'Android 2.2'); 
print (json_encode($data)); 
?> 

2. Contents of Android Layout Manifest and Activity files
 main.xml file

<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="216dp"
        android:layout_height="36dp"
        android:layout_weight="1"
        android:layout_x="66dp"
        android:layout_y="192dp"
        android:textAppearance="?android:attr/textAppearanceMedium" />

</AbsoluteLayout>

manifest.xml 
You need to add internet permissions 
 

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.json.php"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="8" />
    <uses-permission android:name="android.permission.INTERNET"/>

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:name=".JSONExampleActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Android activity 

package com.json.php;

import android.app.Activity;
import android.os.Bundle;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import android.widget.TextView;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;


public class JSONExampleActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://codeincloud.tk/json_android_example.php");
        TextView textView = (TextView)findViewById(R.id.textView1);
  try {
   
   HttpResponse response = httpclient.execute(httppost);
   String jsonResult = inputStreamToString(response.getEntity().getContent()).toString();
   JSONObject object = new JSONObject(jsonResult);

   String name = object.getString("name");
      String verion = object.getString("version");
      textView.setText(name + " - " + verion);
      
  } 
  catch (JSONException e) {
   e.printStackTrace();
  } 
  catch (ClientProtocolException e) {
   e.printStackTrace();
  } 
  catch (IOException e) {
   e.printStackTrace();
  }


       }
    private StringBuilder inputStreamToString(InputStream is) {
        String rLine = "";
        StringBuilder answer = new StringBuilder();
        BufferedReader rd = new BufferedReader(new InputStreamReader(is));
         
        try {
         while ((rLine = rd.readLine()) != null) {
          answer.append(rLine);
           }
        }
         
        catch (IOException e) {
            e.printStackTrace();
         }
        return answer;
       }
}

 Result

Click here to download the Android project.

That's it
 Happy coding! :)