Source code cara membuat tombol Exit di Android

/*Code java :

package com.example.membuattbexit;

import android.support.v7.app.ActionBarActivity;

import android.os.Bundle;

import android.view.Menu;

import android.view.MenuItem;

import android.text.Editable;

import android.text.TextWatcher;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.ArrayAdapter;

import android.widget.AutoCompleteTextView;

import android.widget.Button;

import android.widget.TextView;

public class ExitActivity extends ActionBarActivity implements TextWatcher {

      private Button keluar;

      TextView seleksi;

      AutoCompleteTextView edit;

      String[] item = { "Januari", "February", "March", "April", "Mei", "Juni", "Juli", "Agustus", "September", "Oktober","November", "Dsember"};

      @Override

      protected void onCreate(Bundle savedInstanceState) {

            super.onCreate(savedInstanceState);

            setContentView(R.layout.activity_exit);

           

            seleksi = (TextView) findViewById(R.id.seleksi);

            edit = (AutoCompleteTextView) findViewById(R.id.edit);

            edit.addTextChangedListener(this);

            edit.setAdapter(new ArrayAdapter<String>(this,

            android.R.layout.simple_dropdown_item_1line, item));

            keluar = (Button) this.findViewById(R.id.keluar);

            keluar.setOnClickListener(new OnClickListener() {

                  @Override public void onClick(View arg0) {

                        ExitActivity.this.finish(); }

                  });

            }

      public void onTextChanged(CharSequence s, int start, int before, int count) {

      seleksi.setText(edit.getText());

      }

      public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            // not used

            }

      public void afterTextChanged(Editable s)

      {

            // not used } }

      }

      @Override

      public boolean onCreateOptionsMenu(Menu menu) {

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

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

            return true;

      }

      @Override

      public boolean onOptionsItemSelected(MenuItem item) {

            // Handle action bar item clicks here. The action bar will

            // automatically handle clicks on the Home/Up button, so long

            // as you specify a parent activity in AndroidManifest.xml.

            int id = item.getItemId();

            if (id == R.id.action_settings) {

                  return true;

            }

            return super.onOptionsItemSelected(item);

      }

}

 /*Xml Code*/

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout

    xmlns:android="http://schemas.android.com/apk/res/android"

    android:orientation="vertical"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent">

<TextView

    android:id="@+id/seleksi"

    android:layout_width="fill_parent"

    android:layout_height="wrap_content"/>

 <AutoCompleteTextView

     android:id="@+id/edit"

     android:layout_width="fill_parent"

     android:layout_height="wrap_content"

     android:completionThreshold="3"/>

 <Button

     android:layout_height="wrap_content"

     android:text="Keluar"

     android:layout_width="wrap_content"

     android:id="@+id/keluar"

     android:layout_gravity="right"/>

 </LinearLayout>