两个Service之间相互监视的实现
在实际开发中可能需要用到两个Service相互监视的情况，本示例就是实现此功能以作参考。
服务A：
1 public class ServiceA extends Service { 2 3 4 private static final String TAG = ServiceA.class.getSimpleName(); 5 MyBinder mBinder; 6 MyServiceConnection mServiceConnection; 7 PendingIntent mPendingIntent; 8 9 @Override 10 public void onCreate() { 11 super.onCreate(); 12 13 if(mBinder==null) 14 { 15 mBinder=new MyBinder(); 16 } 17 mServiceConnection=new MyServiceConnection(); 18 } 19 20 @Override 21 public int onStartCommand(Intent intent, int flags, int startId) { 22 ServiceA.this.bindService(new Intent(ServiceA.this,ServiceB.class),mServiceConnection, Context.BIND_IMPORTANT); 23 mPendingIntent=PendingIntent.getService(this,0,intent,0); 24 Notification.Builder builder=new Notification.Builder(this); 25 builder.setTicker("守护服务A启动中") 26 .setContentText("我是来守护服务B的") 27 .setContentTitle("守护服务A") 28 .setSmallIcon(R.mipmap.ic_launcher) 29 .setContentIntent(mPendingIntent) 30 .setWhen(System.currentTimeMillis()); 31 Notification notification=builder.build(); 32 33 startForeground(startId,notification); 34 35 36 return START_STICKY; 37 } 38 39 @Override 40 public IBinder onBind(Intent intent) { 41 return mBinder; 42 } 43 44 public class MyBinder extends IBridgeInterface.Stub { 45 46 @Override 47 public String getName() throws RemoteException { 48 return "name:"+TAG; 49 } 50 } 51 52 class MyServiceConnection implements ServiceConnection { 53 54 @Override 55 public void onServiceConnected(ComponentName componentName, IBinder iBinder) { 56 String name=null; 57 try { 58 name= IBridgeInterface.Stub.asInterface(iBinder).getName(); 59 } catch (RemoteException e) { 60 e.printStackTrace(); 61 } 62 63 64 Toast.makeText(ServiceA.this,name+"连接成功",Toast.LENGTH_SHORT).show(); 65 } 66 67 @Override 68 public void onServiceDisconnected(ComponentName componentName) { 69 Toast.makeText(ServiceA.this,TAG+"断开连接",Toast.LENGTH_SHORT).show(); 70 71 ServiceA.this.startService(new Intent(ServiceA.this,ServiceB.class)); 72 73 ServiceA.this.bindService(new Intent(ServiceA.this,ServiceB.class),mServiceConnection, Context.BIND_IMPORTANT); 74 75 } 76 } 77 78 79 }
服务B：
1 public class ServiceB extends Service { 2 3 private static final String TAG = ServiceB.class.getSimpleName(); 4 private PendingIntent mPendingIntent; 5 private MyBinder mBinder; 6 private MyServiceConnection mServiceConnection; 7 8 @Override 9 public IBinder onBind(Intent intent) { 10 return mBinder; 11 } 12 13 @Override 14 public void onCreate() { 15 super.onCreate(); 16 if (mBinder == null) { 17 mBinder = new MyBinder(); 18 } 19 20 mServiceConnection = new MyServiceConnection(); 21 } 22 23 @Override 24 public int onStartCommand(Intent intent, int flags, int startId) { 25 this.bindService(new Intent(ServiceB.this, ServiceA.class), mServiceConnection, Context.BIND_IMPORTANT); 26 mPendingIntent = PendingIntent.getService(this, 0, intent, 0); 27 Notification.Builder builder = new Notification.Builder(this); 28 29 builder.setTicker("守护服务B启动中") 30 .setContentText("我是来守护服务A的") 31 .setContentTitle("守护服务B") 32 .setSmallIcon(R.mipmap.ic_launcher) 33 .setContentIntent(mPendingIntent) 34 .setWhen(System.currentTimeMillis()); 35 Notification notification = builder.build(); 36 startForeground(startId, notification); 37 38 return START_STICKY; 39 } 40 41 public class MyBinder extends IBridgeInterface.Stub { 42 43 @Override 44 public String getName() throws RemoteException { 45 return "name:"+TAG; 46 } 47 } 48 49 class MyServiceConnection implements ServiceConnection { 50 51 @Override 52 public void onServiceConnected(ComponentName componentName, IBinder iBinder) { 53 String name=null; 54 try { 55 name=IBridgeInterface.Stub.asInterface(iBinder).getName(); 56 } catch (RemoteException e) { 57 e.printStackTrace(); 58 } 59 Toast.makeText(ServiceB.this, name + "连接成功", Toast.LENGTH_SHORT).show(); 60 } 61 62 @Override 63 public void onServiceDisconnected(ComponentName componentName) { 64 Toast.makeText(ServiceB.this, TAG + "断开连接", Toast.LENGTH_SHORT).show(); 65 66 ServiceB.this.startService(new Intent(ServiceB.this, ServiceA.class)); 67 ServiceB.this.bindService(new Intent(ServiceB.this, ServiceA.class), mServiceConnection, Context.BIND_IMPORTANT); 68 } 69 } 70 71 72 }
IBridgeInterface.aidl
1 interface IBridgeInterface { 2 String getName(); 3 }
界面：
1 public class MainActivity extends Activity { 2 3 4 @Override 5 protected void onCreate(Bundle savedInstanceState) { 6 super.onCreate(savedInstanceState); 7 setContentView(R.layout.activity_main); 8 9 startService(new Intent(this, ServiceA.class)); 10 startService(new Intent(this, ServiceB.class)); 11 } 12 13 }
AndroidManifest.xml
1 <service android:name=".services.ServiceA" /> 2 <service 3 android:name=".services.ServiceB" 4 android:process=":remote" />
由于涉及到跨进程，onServiceConnected() 方法中使用
IBridgeInterface.Stub.asInterface(iBinder).getName();
而不能直接类型转换
((ServiceA.MyBinder)iBinder).getName();
onStartCommand
onStartCommand() 方法必须返回整型数。整型数是一个值，用于描述系统应该如何在服务终止的情况下继续运行服务。
返回的值必须是以下常量之一：
START_NOT_STICKY
如果系统在 onStartCommand() 返回后终止服务，则除非有挂起 Intent 要传递，否则系统不会重建服务。
START_STICKY
如果系统在 onStartCommand() 返回后终止服务，则会重建服务并调用 onStartCommand()，但绝对不会重新传递最后一个 Intent。相反，除非有挂起 Intent 要启动服务（在这种情况下，将传递这些 Intent ），否则系统会通过空 Intent 调用 onStartCommand()。这适用于不执行命令、但无限期运行并等待作业的媒体播放器（或类似服务）。
START_REDELIVER_INTENT
如果系统在 onStartCommand() 返回后终止服务，则会重建服务，并通过传递给服务的最后一个 Intent 调用 onStartCommand()。任何挂起 Intent 均依次传递。这适用于主动执行应该立即恢复的作业（例如下载文件）的服务。
