Android Login Email & Password Validation

Here i going to validate the email and password.
The complete source code for the LoginValidationProject

follow my steps, Create the project with following attributes.

Project name         : LoginValidationExample
Build Target           : Android 2.1
Application name   : LoginValidationExample
Package name        : com.android.dhamu.validation
Create Activity      : LoginScreen

Step 1:

 Rename the main.xml file as login_screen.xml. Copy and paste the below xml coding in it.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:text="Login Screen"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:textColor="#00ff00" />

    <LinearLayout
        android:id="@+id/linearLayout2"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="50dip"
        android:orientation="vertical" >

        <LinearLayout
            android:id="@+id/linearLayout1"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:layout_gravity="center"
            android:layout_margin="30dip"
            android:orientation="vertical" >

            <EditText
                android:id="@+id/edt_username"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_marginBottom="10dip"
                android:layout_marginTop="20dip"
                android:hint="Username"
                android:inputType="textEmailAddress"
                android:paddingLeft="10dip"
                android:paddingRight="10dip"
                android:singleLine="true"
                android:typeface="normal" >

                <requestFocus>
                </requestFocus>
            </EditText>

            <EditText
                android:id="@+id/edt_password"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_marginBottom="20dip"
                android:layout_marginTop="10dip"
                android:hint="Password"
                android:inputType="textPassword"
                android:paddingLeft="10dip"
                android:paddingRight="10dip"
                android:password="true"
                android:singleLine="true"
                android:typeface="normal" >
            </EditText>

            <Button
                android:id="@+id/btn_login"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="center"
                android:text="Login" >
            </Button>
        </LinearLayout>
    </LinearLayout>

</LinearLayout>

Now you got the screen like

Step 2:

Create the home_screen.xml in res/layout folder, Then copy and paste the below xml coding in it.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:text="Home Screen"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:textColor="#00ff00" />

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:gravity="center"
        android:orientation="vertical" >

        <TextView
            android:id="@+id/textView2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Login completed successfully"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:textColor="#ff00ff" />
    </LinearLayout>

</LinearLayout>

Now you got the screen like

Step 3:

Copy the below java coding and paste it in LoginScreen.java file.

package com.android.dhamu.validation;

import java.util.regex.Pattern;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class LoginScreen extends Activity {
    EditText edtUsername,edtPassword;
    Button btnLogin;
    String strUsername,strPassword;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.login_screen);
       
        edtUsername = (EditText)this.findViewById(R.id.edt_username);
        edtPassword = (EditText)this.findViewById(R.id.edt_password);
        btnLogin = (Button)this.findViewById(R.id.btn_login);
       
        btnLogin.setOnClickListener(new OnClickListener() {
           
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                strUsername = edtUsername.getText().toString().trim();
                strPassword = edtPassword.getText().toString().trim();
               
               
                if (isInternetConnected()) {

                    if (isUserNameNotEmpty()) {

                        if (isValidEmail()) {

                            if (isPassWordNotEmpty()) {
                               
                                LoginScreen.this.startActivity(new Intent(
                                        LoginScreen.this,
                                        HomeScreen.class));
                            }
                        }

                    }

                }
               
               
            }
        });
       
    }
   
   
    public boolean isInternetConnected() {

        ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        if (connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE)
                .getState() == NetworkInfo.State.CONNECTED
                || connectivityManager.getNetworkInfo(
                        ConnectivityManager.TYPE_WIFI).getState() == NetworkInfo.State.CONNECTED) {
            return true;
        } else
            Toast.makeText(this, "Please check your internet connection",
                    Toast.LENGTH_SHORT).show();
        return false;
    }

   
    // Checking the Email whether it is valid or not.

    private boolean isValidEmail() {
        final Pattern EMAIL_ADDRESS_PATTERN = Pattern
                .compile("[a-zA-Z0-9+._%-+]{1,256}" + "@"
                        + "[a-zA-Z0-9][a-zA-Z0-9-]{0,64}" + "(" + "."
                        + "[a-zA-Z0-9][a-zA-Z0-9-]{0,25}" + ")+");

       

        if (EMAIL_ADDRESS_PATTERN.matcher(strUsername).matches()
                && !strUsername.equalsIgnoreCase("")) {

            return true;
        } else {
            Toast.makeText(this, "Please enter valid Email ID", Toast.LENGTH_SHORT)
                    .show();
            return false;
        }

    }
   

    // Checking whether the username is not empty

    public boolean isUserNameNotEmpty() {

        if (strUsername.equalsIgnoreCase("")) {
            Toast.makeText(this, "Please enter the Email ID", Toast.LENGTH_SHORT)
                    .show();
            return false;
        } else {
            return true;
        }

    }

   
    // Checking whether the password is not empty

    public boolean isPassWordNotEmpty() {

        if (strPassword.equalsIgnoreCase("")) {
            Toast.makeText(this, "Please enter the Password", Toast.LENGTH_SHORT)
                    .show();
            return false;
        } else {
            return true;
        }

    }

}

Step 4:

Create the HomeScreen.java in src folder and paste the below java code in it.

package com.android.dhamu.validation;

import android.app.Activity;
import android.os.Bundle;

public class HomeScreen extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.home_screen);
    }
}

Step 5:

AndroidManifest.xml file

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

    <uses-sdk
        android:minSdkVersion="7"
        android:targetSdkVersion="7" />

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

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

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

</manifest>

In AndroidManifest.xml file,

1) Add the permission for INTERNET and ACCESS_NETWORK_STATE.

2) Add the HomeScreen.java in application.

Here is the complete SourceCode for LoginValidation.