Creating Simple Android Login Application

 

Operating System:

In this tutorial we will try to create a Simple Login Application Using Android. Android is basically a piece of software that allows your hardware to function. The android is an open-source operating system it's free and user friendly to mobile developers. Android is available to any device such as TV, phones, watches, etc.

So now let's do the coding.

Layout Design

We will now create the design for the application, first, locate the layout folder and select the activity_login.xml. Then copy and paste the code below.

activity_login.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.razormist.simpleloginapplication.Login">
 
 
    <TextView
        android:id="@+id/tv_login"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="11dp"
        android:layout_marginStart="11dp"
        android:layout_marginTop="13dp"
        android:text="Login"
        android:fontFamily="sans-serif-condensed"
        android:textSize="30sp"/>
 
 
 
    <TextView
        android:id="@+id/tv_username"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/tv_login"
        android:layout_alignStart="@+id/tv_login"
        android:layout_below="@+id/tv_login"
        android:layout_marginTop="80dp"
        android:fontFamily="monospace"
        android:text="Username"
        android:textSize="25sp" />
 
    <EditText
        android:id="@+id/et_username"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/tv_username"
        android:ems="17"
        android:layout_alignLeft="@+id/tv_username" />
 
 
 
    <TextView
        android:id="@+id/tv_password"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/et_username"
        android:layout_alignStart="@+id/et_username"
        android:layout_below="@+id/et_username"
        android:layout_marginTop="33dp"
        android:fontFamily="monospace"
        android:text="Password"
        android:textSize="25sp" />
 
    <EditText
        android:id="@+id/et_password"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="textPassword"
        android:ems="17"
        android:layout_below="@+id/tv_password"
        android:layout_alignLeft="@+id/tv_password" />
 
 
    <Button
        android:id="@+id/btn_login"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:layout_below="@id/et_password"
        android:layout_centerInParent="true"
        android:ems="12"
        android:layout_marginTop="30dp"
        android:text="Login"/>
 
 
</RelativeLayout>

Next is create another layout by right-clicking the layout folder namely activity_user.xml. Then write these blocks code to the layout script.

activity_user.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.razormist.simpleloginapplication.User">
 
    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Welcome"
        android:textSize="40sp"
        android:layout_marginTop="177dp"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true" />
 
    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="30sp"
        android:layout_marginTop="30dp"
        android:layout_centerInParent="true"
        android:layout_below="@+id/textView1"
        android:text="Administrator"/>
 
</RelativeLayout>

Android Manifest File

The Android Manifest file provides essential information about your app to the Android system in which the system must required before running the code.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.razormist.simpleloginapplication">
 
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".Login"
            android:configChanges="orientation"
            android:screenOrientation="portrait">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
 
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".User"
            android:configChanges="orientation"
            android:screenOrientation="portrait">
            <intent-filter>
                <action android:name="com.razormist.simpleloginapplication.User" />
 
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
    </application>
</manifest>

The Main Function

Login.java

This code contains the main function of the application. This code will login the user when the username and password are entered correctly. To create the function just write the code inside the Login class

package com.razormist.simpleloginapplication;
 
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
 
public class Login extends AppCompatActivity {
 
    EditText et_username, et_password;
    Button btn_login;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
 
        Login();
    }
 
    void Login(){
        et_username = (EditText)findViewById(R.id.et_username);
        et_password = (EditText)findViewById(R.id.et_password);
        btn_login = (Button)findViewById(R.id.btn_login);
 
        btn_login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(et_username.getText().toString().equals("admin") && et_password.getText().toString().equals("admin")){
                    Toast.makeText(Login.this, "Username and Password is correct", Toast.LENGTH_SHORT).show();
                    Intent intent = new Intent(Login.this,User.Class);
                    startActivity(intent);
                }else{
                    Toast.makeText(Login.this, "Username or Password is incorrect", Toast.LENGTH_SHORT).show();
                }
            }
        });
    }
}

User.java

This code will render a new layout after the user successfully login. This is where the user is redirect after entering the correction information. Just write these block of codes inside the User class.

package com.razormist.simpleloginapplication;
 
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
 
public class User extends AppCompatActivity {
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_user);
    }
}

Try to run and see if it works:

username: admin 
password: admin

download Code

Note: Due to the size or complexity of this submission, the author has submitted it as a .zip file to shorten your download time. After downloading it, you will need a program like Winzip to decompress it.

Virus note: All files are scanned once-a-day by SourceCodester.com for viruses, but new viruses come out every day, so no prevention program can catch 100% of them.

FOR YOUR OWN SAFETY, PLEASE:

1. Re-scan downloaded files using your personal virus checker before using it.
2. NEVER, EVER run compiled files (.exe's, .ocx's, .dll's etc.)--only run source code.