Android RatingBar.

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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <RatingBar
        android:id="@+id/ratingBar1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="94dp" />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:text="@string/submit" />

</RelativeLayout>

MainActivity.java

package com.mahi.ratingbar;

import android.os.Bundle;

import android.app.Activity;

import android.view.Menu;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.RatingBar;

import android.widget.Toast;

public class MainActivity extends Activity {

RatingBar r;  

Button b;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

addListenerOnButtonClick();

}

public void addListenerOnButtonClick(){  

        r=(RatingBar)findViewById(R.id.ratingBar1);  

        b=(Button)findViewById(R.id.button1);  

        //Performing action on Button Click  

        b.setOnClickListener(new OnClickListener(){  

  

            public void onClick(View v) {  

                //Getting the rating and displaying it on the toast  

                String rating=String.valueOf(r.getRating());  

                Toast.makeText(getApplicationContext(), rating, Toast.LENGTH_LONG).show();  

            }  

              

        });  

    }

@Override

public boolean onCreateOptionsMenu(Menu menu) {

// Inflate the menu; this adds items to the action bar if it is present.

getMenuInflater().inflate(R.menu.main, menu);

return true;

}

}

Output: