activity_main.xml
--------------------
<?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/lblRateMe"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Rate Me"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <RatingBar
        android:id="@+id/ratingBar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:numStars="4"
        android:stepSize="1.0"
        android:rating="2.0" />

    <Button
        android:id="@+id/btnSubmit"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Submit" />

    <LinearLayout
        android:id="@+id/linearLayout1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >

        <TextView
            android:id="@+id/lblResult"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Result : "
            android:textAppearance="?android:attr/textAppearanceLarge" />

        <TextView
            android:id="@+id/txtRatingValue"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text=""
            android:textAppearance="?android:attr/textAppearanceSmall" />

    </LinearLayout>

</LinearLayout>


MainActivity.java
-------------------
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.RatingBar;
import android.widget.RatingBar.OnRatingBarChangeListener;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {

    private RatingBar ratingBar;
    private TextView txtRatingValue;
    private Button btnSubmit;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        addListenerOnRatingBar();
        addListenerOnButton();

    }

    public void addListenerOnRatingBar() {

        ratingBar = (RatingBar) findViewById(R.id.ratingBar);
        txtRatingValue = (TextView) findViewById(R.id.txtRatingValue);

        // if rating value is changed,
        // display the current rating value in the result (textview) automatically
        ratingBar.setOnRatingBarChangeListener(new OnRatingBarChangeListener() {
            public void onRatingChanged(RatingBar ratingBar, float rating,
                                        boolean fromUser) {

                txtRatingValue.setText(String.valueOf(rating));

            }
        });
    }

    public void addListenerOnButton() {

        ratingBar = (RatingBar) findViewById(R.id.ratingBar);
        btnSubmit = (Button) findViewById(R.id.btnSubmit);

        // if clicked, then display the current rating value.
        btnSubmit.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {

                Toast.makeText(MainActivity.this,
                        String.valueOf(ratingBar.getRating()),
                        Toast.LENGTH_SHORT).show();
            }

        });

    }
}