Working with Multiple Buttons

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="104dp"
        android:layout_marginTop="20dp"
        android:text="Button1" />

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/button1"
        android:layout_below="@+id/button1"
        android:layout_marginTop="34dp"
        android:text="Button2" />

    <Button
        android:id="@+id/button3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/button2"
        android:layout_centerVertical="true"
        android:text="Button3" />

    <Button
        android:id="@+id/button4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/button3"
        android:layout_below="@+id/button3"
        android:layout_marginTop="34dp"
        android:text="Button4" />

    <Button
        android:id="@+id/button5"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/button4"
        android:layout_alignParentBottom="true"
        android:layout_marginBottom="24dp"
        android:text="Button5" />

</RelativeLayout>

MainActivity.java

package com.blogspot.kantapp.workingwithmultiplebuttons;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener {
    Button b1,b2,b3,b4,b5;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        b1 = (Button)findViewById( R.id.button1);
        b2 = (Button)findViewById(R.id.button2);
        b3 = (Button)findViewById(R.id.button3);
        b4 = (Button)findViewById(R.id.button4);
        b5 = (Button)findViewById(R.id.button5);



        b1.setOnClickListener(this);
        b2.setOnClickListener(this);
        b3.setOnClickListener(this);
        b4.setOnClickListener(this);
        b5.setOnClickListener(this);

    }
    @Override
    public void onClick(View v) {

        switch (v.getId()) {
            case R.id.button1:
                Toast.makeText(getApplicationContext(), "button1 is working", 3000).show();
                break;

            case R.id.button2:
                Toast.makeText(getApplicationContext(), "button2 is working", 3000).show();
                break;

            case R.id.button3:
                Toast.makeText(getApplicationContext(), "button3 is working", 3000).show();
                break;

            case R.id.button4:
                Toast.makeText(getApplicationContext(), "button4 is working", 3000).show();
                break;

            case R.id.button5:
                Toast.makeText(getApplicationContext(), "button5 is working", 3000).show();
                break;
        }

    }
}