Question

我有一个Service类，它是一个从java客户端接收数据的服务器，我能够检索数据但是当我试图将数据从服务广播到MainActivity时，sendBroadcast（intent）给出了一个服务中的NPE并且它没有广播消息..我查看了几个答案，但我无法弄清楚问题..所以我发布了这个问题.. 以下是我的服务部分

public class Service_ extends Service implements Runnable {
BroadcastReceiver broadcaster;
Intent intent;
static final public String BROADCAST_ACTION = "com.mes.broadcast";
private static ServerSocket server;
private static int port = 9800;
ObjectOutputStream oos = null;
ObjectInputStream ois = null;

@Nullable
@Override
public IBinder onBind(Intent intent) {
    return null;
}

@Override
public void onCreate() {
    super.onCreate();
    Log.d("sri", "onCreate---->Service");

}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {

    Log.d("sri","onStartCommand(Intent intent, int flags, int startId)---->Service");
    Service_ s = new Service_();
    Thread t = new Thread(s);
    Log.d("sri","going to start thread---->Service");
    t.start();
    return super.onStartCommand(intent, flags, startId);

    }
   @Override
   public void run() {
   Log.d("sri","run()---->Service");
    try {

    }catch(Exception e){
      // code to connect to java client .......it works fine and  also   obtained data ..I WANTED THIS DATA TO BE SENT TO THE ACTIVITY
            intent = new Intent(BROADCAST_ACTION);Log.d("sri","sendResult----->putExtra");
            intent.putExtra("message", message);
            Log.d("sri", "sendResult---->SendBroadcast");
            sendBroadcast(intent);//THIS LINE GIVES ME NPE LINE:109

      }}

我的Stacktrace是

     E/AndroidRuntime: FATAL EXCEPTION: Thread-11724
     java.lang.NullPointerException
    atandroid.content.ContextWrapper.sendBroadcast(ContextWrapper.java:338)
   at airhost.server_client_service_.Service_.run(Service_.java:109)
   at java.lang.Thread.run(Thread.java:838)

我的主要活动

      //imports....

     public class MainActivity extends AppCompatActivity {
     TextView result;
     Button button;
     BroadcastReceiver receiver;
     Intent serviceIntent;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    result = (TextView) findViewById(R.id.textView);
    button = (Button) findViewById(R.id.button);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            serviceIntent = new Intent(getApplicationContext(),
                    Service_.class);
            Log.d("sri", "onResume-->startService-----> Activity");
            startService(serviceIntent);
        }
    });

    receiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            Log.d("sri", "BroadcastReceiver-->onReceive-----> Activity");
            String message = intent.getStringExtra("message");
            result.setText(message);
        }
    };

}

protected void onResume() {
    super.onResume();
    Log.d("sri", "onResume-->registerReceiver-----> Activity");
    registerReceiver(receiver, new IntentFilter(
            Service_.BROADCAST_ACTION));
}
@Override
protected void onPause() {
    super.onPause();
    Log.d("sri", "onPause-------> Activity");
    stopService(serviceIntent);
    unregisterReceiver(receiver);
}
}

服务中的sendBroadcast（intent）中的NullPointerException

0 个答案: