MainActivity.java

package com.example.android.justjava;

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.widget.TextView;

/**
 * This app displays an order form to order coffee.
 */
public class MainActivity extends ActionBarActivity {

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

    /**
     * This method is called when the order button is clicked.
     */
    public void submitOrder(View view) {
        display(1);
    }

    /**
     * This method displays the given quantity value on the screen.
     */
    private void display(int number) {
        TextView quantityTextView = (TextView) findViewById(
                R.id.quantity_text_view);
        quantityTextView.setText("" + number);
    }
}

Use this, Keep your package name unchanged.

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

/**

• This app displays an order form to order coffee.
  */
  public class MainActivity extends Activity {

  @OverRide
  protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  }

  /**

  • This method is called when the order button is clicked.
    */
    public void submitOrder(View view) {
    display(1);
    }

  /**

  • This method displays the given quantity value on the screen.
    */
    private void display(int number) {
    TextView quantityTextView = (TextView) findViewById(
    R.id.quantity_text_view);
    quantityTextView.setText("" + number);
    }
    }