Tableau en java pour android

Bonjour,

J'essaye de faire une application android(une calculette), j'ai fait des layouts xml pour chaque button. Puis je déclare un tableau ou je lui reli mes boutons.
Je vous montre le code ce sera plus simple ==

package com.example.calc.tata;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.widget.Button;
import android.widget.EditText;

public class MainActivity extends Activity {
 EditText ecran;
 Button button[];
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  
  button[0] = (Button) findViewById(R.id.button0);
  button[1] = (Button) findViewById(R.id.button1);
  button[2] = (Button) findViewById(R.id.button2);
  button[3] = (Button) findViewById(R.id.button3);
  button[4] = (Button) findViewById(R.id.button4);
  button[5] = (Button) findViewById(R.id.button5);
  button[6] = (Button) findViewById(R.id.button6);
  button[7] = (Button) findViewById(R.id.button7);
  button[8] = (Button) findViewById(R.id.button8);
  button[9] = (Button) findViewById(R.id.button9);
  button[10] = (Button) findViewById(R.id.buttonPlus);
  button[11] = (Button) findViewById(R.id.buttonMoins);
  button[12] = (Button) findViewById(R.id.buttonMultiplier);
  button[13] = (Button) findViewById(R.id.buttonDivision);
  button[14] = (Button) findViewById(R.id.button10);
  button[15] = (Button) findViewById(R.id.buttonPoint);
  button[16] = (Button) findViewById(R.id.buttonC);
  
   ecran = (EditText) findViewById(R.id.editText01); 
  
  }

 @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;
 }

}

L'application compile mais ne marche pas sous android.

Merci de votre aide