Think AndroiD: 2013

Android Login Screen Using HttpClient

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.

Here is the screen shot of login screen.

Try the same with the below code :

Code

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://localhost_address");

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://localhost_address"

</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://localhost_address"

package="com.sencide"

android:versionCode="1"

android:versionName="1.0">

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

<activity android:name=".AndroidLogin"

android:label="@string/app_name">

<intent-filter>

</intent-filter>

</activity>

</application>

</manifest>

Friday, 22 November 2013