MainActivity.java

package com.tutorial.notification.ammar;

import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.support.v4.app.NotificationCompat;
import android.support.v4.app.TaskStackBuilder;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_notifications);
        Button ToastBut = (Button) findViewById(R.id.toastButton);
        Button NotBut = (Button) findViewById(R.id.notiButton);
        ToastBut.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(getBaseContext(), "This is a toast message", Toast.LENGTH_SHORT).show();
            }
        });
        NotBut.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(getBaseContext());
                mBuilder.setSmallIcon(R.drawable.message);
                mBuilder.setContentTitle("this is notification");
                mBuilder.setContentText("This is the text you see in the notification");

                Intent resultIntent = new Intent(getBaseContext(), MainActivity.class);
                TaskStackBuilder stackBuilder = TaskStackBuilder.create(getBaseContext());
                stackBuilder.addParentStack(MainActivity.class);

                stackBuilder.addNextIntent(resultIntent);
                PendingIntent resultPendingIntent = stackBuilder.getPendingIntent(0,PendingIntent.FLAG_UPDATE_CURRENT);

                mBuilder.setContentIntent(resultPendingIntent);

                NotificationManager mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

                mNotificationManager.notify(0, mBuilder.build());
            }
        });
    }
}