Android JSON Example

In this post, you an learn how to decode the JSON data which is in encoded format in Android using few source code examples. Here we are going to see an example of JSON reading in android.

Let us have a simple PHP web service which encodes the string array into JSON format. I'm going to access that web service using Android http client and then it decodes the JSON data.

Consider a simple web service in PHP which encodes the string array in JSON format.

<?php

$data = array('name' => 'android', 'version' => 'Android 2.3'); 

print (json_encode($data)); 

?>

Now consider the following activity_main.xml

<?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>

Add Uses permission to the android manifest xml file.

<?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>

Now activitymain.java

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://udhayacode.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;

       }

}