package com.example.servdemo;import android.app.Activity;import android.app.ActionBar;import android.app.Fragment;import android.content.Intent;import android.os.Bundle;import android.view.LayoutInflater;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.view.View.OnClickListener;import android.view.ViewGroup;import android.widget.Button;import android.os.Build;public class MainActivity extends Activity implements OnClickListener {    private Button btnStartService, btnStopService;    private Intent serviceIntent;        @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);                serviceIntent = new Intent(this, EchoService.class);                btnStartService = (Button) findViewById(R.id.btnStartService);        btnStopService = (Button) findViewById(R.id.btnStopService);                btnStartService.setOnClickListener(this);        btnStopService.setOnClickListener(this);    }    @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;    }    @Override    public void onClick(View v) {                switch (v.getId()) {        case R.id.btnStartService:            startService(serviceIntent);            break;        case R.id.btnStopService:            stopService(serviceIntent);            break;        }    }}

package com.example.servdemo;import android.app.Service;import android.content.Intent;import android.os.IBinder;public class EchoService extends Service {    @Override    public IBinder onBind(Intent intent) {        return null;    }        @Override    public void onCreate() {        // TODO Auto-generated method stub        System.out.println("Service Start!");        super.onCreate();    }        @Override    public void onDestroy() {        // TODO Auto-generated method stub        System.out.println("Service Stop!");        super.onDestroy();    }}