Android Login Screen Using HttpClient

I have updated this code to use web service and open new screen if the login is successful in my post Android Web Service Access Tutorial.

In Android we can use HTTP POST request with org.apache.http.client.HttpClient to post data to a URL. This sample project illustrate how we can post data to a URL and get the response.

package com.sencide;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class AndroidLogin extends Activity implements OnClickListener {
 
 Button ok,back,exit;
 TextView result;
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        // Login button clicked
        ok = (Button)findViewById(R.id.btn_login);
        ok.setOnClickListener(this);
        
        result = (TextView)findViewById(R.id.lbl_result);
        
    }
    
    public void postLoginData() {
        // Create a new HttpClient and Post Header
        HttpClient httpclient = new DefaultHttpClient();
        
        /* login.php returns true if username and password is equal to saranga */
        HttpPost httppost = new HttpPost("http://www.sencide.com/blog/login.php");

        try {
            // Add user name and password
         EditText uname = (EditText)findViewById(R.id.txt_username);
         String username = uname.getText().toString();

         EditText pword = (EditText)findViewById(R.id.txt_password);
         String password = pword.getText().toString();
         
            List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
            nameValuePairs.add(new BasicNameValuePair("username", username));
            nameValuePairs.add(new BasicNameValuePair("password", password));
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

            // Execute HTTP Post Request
            Log.w("SENCIDE", "Execute HTTP Post Request");
            HttpResponse response = httpclient.execute(httppost);
            
            String str = inputStreamToString(response.getEntity().getContent()).toString();
            Log.w("SENCIDE", str);
            
            if(str.toString().equalsIgnoreCase("true"))
            {
             Log.w("SENCIDE", "TRUE");
             result.setText("Login successful");   
            }else
            {
             Log.w("SENCIDE", "FALSE");
             result.setText(str);             
            }

        } catch (ClientProtocolException e) {
         e.printStackTrace();
        } catch (IOException e) {
         e.printStackTrace();
        }
    } 
  
    private StringBuilder inputStreamToString(InputStream is) {
     String line = "";
     StringBuilder total = new StringBuilder();
     // Wrap a BufferedReader around the InputStream
     BufferedReader rd = new BufferedReader(new InputStreamReader(is));
     // Read response until the end
     try {
      while ((line = rd.readLine()) != null) { 
        total.append(line); 
      }
     } catch (IOException e) {
      e.printStackTrace();
     }
     // Return full string
     return total;
    }

    @Override
    public void onClick(View view) {
      if(view == ok){
        postLoginData();
      }
    }

}

Following code is the content of mail.xml file that is used in the above code.

<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
>
<EditText android:layout_width="150px" android:layout_height="wrap_content" android:textSize="18sp" android:id="@+id/txt_username" android:layout_y="132dip" android:layout_x="128dip"></EditText>
<EditText android:layout_width="150px" android:layout_height="wrap_content" android:textSize="18sp" android:password="true" android:id="@+id/txt_password" android:layout_x="128dip" android:layout_y="192dip"></EditText>
<Button android:layout_width="100px" android:layout_height="wrap_content" android:id="@+id/btn_login" android:layout_x="178dip" android:layout_y="252dip" android:text="Login"></Button>
<TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/lbl_username" android:text="User Name" android:layout_x="37dip" android:layout_y="150dip"></TextView>
<TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/lbl_password" android:text="Password" android:layout_y="207dip" android:layout_x="50dip"></TextView>
<TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/lbl_top" android:textSize="16sp" android:typeface="sans" android:text="Please Loggin First" android:layout_x="29dip" android:layout_y="94dip"></TextView>
<TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_y="312dip" android:layout_x="50dip" android:id="@+id/lbl_result"></TextView>
</AbsoluteLayout>

Following code is the content of AndroidManifest.xml file that is used in this project. There note that I have add the line <uses-permission android:name= "android.permission.INTERNET".

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

 <uses-permission android:name="android.permission.INTERNET" />
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".AndroidLogin"
                  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>

You can download the source code of above project (Password:sara).