Restful Webservice Call And Get And Parse JSON Data- Android Example

In This example calling restful webservice to get json data and parse that json data.

Steps :

   1. Call php file (php) from server and create JSON data in php.

   2. Consume JSON data by android and show on activity.

   3. Parse JSON data and Show parsed data on screen(activity).

Project Structure :

File : src/RestFulWebservice.java

This file contain Asyncronous server request, got JSON response and parse JSON and show on screen.

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;
import org.apache.http.client.HttpClient;
import org.apache.http.impl.client.DefaultHttpClient;
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.app.ProgressDialog;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class RestFulWebservice extends Activity {

	
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
     
        super.onCreate(savedInstanceState);
        setContentView(R.layout.rest_ful_webservice);  
        
        final Button GetServerData = (Button) findViewById(R.id.GetServerData);
         
        GetServerData.setOnClickListener(new OnClickListener() {
            
			@Override
			public void onClick(View arg0) {
				
				// WebServer Request URL
				String serverURL = "/media/webservice/JsonReturn.php";
				
				// Use AsyncTask execute Method To Prevent ANR Problem
		        new LongOperation().execute(serverURL);
			}
        });    
         
    }
     
     
    // Class with extends AsyncTask class
    
    private class LongOperation  extends AsyncTask<String, Void, Void> {
         
    	// Required initialization
    	
        private final HttpClient Client = new DefaultHttpClient();
        private String Content;
        private String Error = null;
        private ProgressDialog Dialog = new ProgressDialog(RestFulWebservice.this);
        String data =""; 
        TextView uiUpdate = (TextView) findViewById(R.id.output);
        TextView jsonParsed = (TextView) findViewById(R.id.jsonParsed);
        int sizeData = 0;  
        EditText serverText = (EditText) findViewById(R.id.serverText);
        
        
        protected void onPreExecute() {
            // NOTE: You can call UI Element here.
             
            //Start Progress Dialog (Message)
           
            Dialog.setMessage("Please wait..");
            Dialog.show();
            
            try{
            	// Set Request parameter
                data +="&" + URLEncoder.encode("data", "UTF-8") + "="+serverText.getText();
	            	
            } catch (UnsupportedEncodingException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} 
            
        }
 
        // Call after onPreExecute method
        protected Void doInBackground(String... urls) {
        	
        	/************ Make Post Call To Web Server ***********/
        	BufferedReader reader=null;
   
	             // Send data 
	            try
	            { 
	              
	               // Defined URL  where to send data
	               URL url = new URL(urls[0]);
	                 
	              // Send POST data request
	   
	              URLConnection conn = url.openConnection(); 
	              conn.setDoOutput(true); 
	              OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream()); 
	              wr.write( data ); 
	              wr.flush(); 
	          
	              // Get the server response 
	               
	              reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
	              StringBuilder sb = new StringBuilder();
	              String line = null;
	            
		            // Read Server Response
		            while((line = reader.readLine()) != null)
		                {
		                       // Append server response in string
		                       sb.append(line + "
");
		                }
	                
	                // Append Server Response To Content String 
	               Content = sb.toString();
	            }
	            catch(Exception ex)
	            {
	            	Error = ex.getMessage();
	            }
	            finally
	            {
	                try
	                {
	     
	                    reader.close();
	                }
	   
	                catch(Exception ex) {}
	            }
        	
            /*****************************************************/
            return null;
        }
         
        protected void onPostExecute(Void unused) {
            // NOTE: You can call UI Element here.
             
            // Close progress dialog
            Dialog.dismiss();
             
            if (Error != null) {
                 
                uiUpdate.setText("Output : "+Error);
                 
            } else {
              
            	// Show Response Json On Screen (activity)
            	uiUpdate.setText( Content );
            	
             /****************** Start Parse Response JSON Data *************/
            	
            	String OutputData = "";
                JSONObject jsonResponse;
                      
                try {
                      
                     /****** Creates a new JSONObject with name/value mappings from the JSON string. ********/
                     jsonResponse = new JSONObject(Content);
                      
                     /***** Returns the value mapped by name if it exists and is a JSONArray. ***/
                     /*******  Returns null otherwise.  *******/
                     JSONArray jsonMainNode = jsonResponse.optJSONArray("Android");
                      
                     /*********** Process each JSON Node ************/
  
                     int lengthJsonArr = jsonMainNode.length();  
  
                     for(int i=0; i < lengthJsonArr; i++) 
                     {
                         /****** Get Object for each JSON node.***********/
                         JSONObject jsonChildNode = jsonMainNode.getJSONObject(i);
                          
                         /******* Fetch node values **********/
                         String name       = jsonChildNode.optString("name").toString();
                         String number     = jsonChildNode.optString("number").toString();
                         String date_added = jsonChildNode.optString("date_added").toString();
                          
                        
                         OutputData += " Name 		    : "+ name +" 
 "
                                     + "Number 		: "+ number +" 
 "
                                     + "Time 				: "+ date_added +" 
 " 
                                     +"--------------------------------------------------
";
                        
                         
                    }
                 /****************** End Parse Response JSON Data *************/     
                     
                     //Show Parsed Output on screen (activity)
                     jsonParsed.setText( OutputData );
                     
                      
                 } catch (JSONException e) {
          
                     e.printStackTrace();
                 }
  
                 
             }
        }
         
    }
	
}

File : rest_ful_webservice.xml

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
  android:fillViewport="true"
  android:background="#FFFFFF"
  android:layout_width="fill_parent" 
  android:layout_height="fill_parent" >
  
<LinearLayout 
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
    <EditText
        android:paddingTop="20px"
        android:id="@+id/serverText"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="" />
    <Button 
        android:paddingTop="10px"
        android:id="@+id/GetServerData" 
    	android:text="Restful Webservice Call" 
    	android:cursorVisible="true"
    	android:clickable="true"
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"  
		android:layout_gravity="center_horizontal"
    /> 
    <TextView
        android:paddingTop="20px"
        android:textStyle="bold"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Server Response (JSON): " />
    <TextView
        android:paddingTop="16px"
        android:id="@+id/output"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Output : Click on button to get server data." />
    
    <TextView
        android:paddingTop="20px"
        android:textStyle="bold"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Parsed JSON : " />
    <TextView
        android:paddingTop="16px"
        android:id="@+id/jsonParsed"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
       />

</LinearLayout>
</ScrollView>

File : AndroidMainifest.xml

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

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="8" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.androidexample.restfulwebservice.RestFulWebservice"
            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>
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
</manifest>

Server file : /media/webservice/JsonReturn.php

Create Json data on server

<?php 

    // Get Post Data
    $data = urldecode($_POST['data']);
      
	$jsonData      = array();
	$jsonTempData  = array();
	 
	 for($i=1;$i<4; $i++)
	   {
		  $jsonTempData = array();
		  $jsonTempData['name'] 		= $data.$i;
		  $jsonTempData['number'] 		= $data.$i;
		  $jsonTempData['date_added'] 	= $data.$i;
		  
		  $jsonData[] = $jsonTempData;
	   }
    
	 $outputArr = array();
	 $outputArr['Android'] = $jsonData;
	 
     // Encode Array To JSON Data
	 print_r( json_encode($outputArr));
	 

 ?>