android - 当应用程序发送到后台时，TCP 连接停止监听

Question

当我将我的应用移至后台时，我的服务停止监听服务器，连接未断开，这就是服务器日志的内容。为什么会发生这种行为？使用 startService 启动服务。

public class LocalService extends Service {
    Socket socket = null;
    public String SERVER_IP = "192.168.1.10";
    public boolean connected = false;

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        if (intent != null) {
            if (intent.hasCategory("connection")) {
                if (connected) {
                    try {
                        if (socket != null) {
                            socket.close();
                            connected = false;
                            // sendBroadcast(intent1);
                        }
                    }
                    catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                else {
                    connect();
                }
            }
        }

        return START_STICKY;
    }

    public void connect() {
        Thread thread = new Thread() {
            @Override
            public void run() {
                // sendBroadcast(intent1);

                try {
                    socket = new Socket(SERVER_IP, 5000);
                    socket.setSoTimeout(5000);

                    connected = true;
                    // sendBroadcast(intent2);

                    OutputStream out = socket.getOutputStream();
                    PrintWriter output = new PrintWriter(out);
                    BufferedReader input = new BufferedReader(new InputStreamReader(socket.getInputStream()));

                    while (true) {
                        String event = input.readLine();
                        // sendBroadcast(intent3);

                        if (event.substring(0, 3).equals("msg")) {
                            String notificationTitle = event.substring(4, event.indexOf("::"));
                            CharSequence tickerText = event.substring(event.indexOf("::") + 2);
                            String notificationContent = event.substring(event.indexOf("::") + 2);

                            Bitmap largeIcon = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);

                            NotificationCompat.Builder mBuilder =
                                    new NotificationCompat.Builder(LocalService.this)
                                            .setSmallIcon(R.drawable.ic_launcher)
                                            .setLargeIcon(largeIcon)
                                            .setTicker(tickerText)
                                            .setContentTitle(notificationTitle)
                                            .setContentText(notificationContent)
                                            .setOnlyAlertOnce(true);

                            Intent resultIntent = new Intent(LocalService.this, ResultActivity.class);
                            TaskStackBuilder stackBuilder = TaskStackBuilder.create(LocalService.this);
                            stackBuilder.addParentStack(ResultActivity.class);
                            stackBuilder.addNextIntent(resultIntent);
                            PendingIntent resultPendingIntent =
                                    stackBuilder.getPendingIntent(
                                            0,
                                            PendingIntent.FLAG_UPDATE_CURRENT
                                    );
                            mBuilder.setContentIntent(resultPendingIntent);
                            NotificationManager mNotificationManager =
                                    (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
                            mNotificationManager.notify(mId, mBuilder.build());
                            mId = mId + 1;
                        }
                    }
                } catch (UnknownHostException e) {
                    e.printStackTrace();
                } catch (java.net.ConnectException e) {
                    e.printStackTrace();
                    // sendBroadcast(intent4);
                } catch (SocketTimeoutException e) {
                    e.printStackTrace();
                } catch(java.net.SocketException e) {
                    e.printStackTrace();
                    connected = false;
                    // sendBroadcast(intent5);
                } catch (IndexOutOfBoundsException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                    connected = false;
                    // sendBroadcast(intenty);
                }
            }
        };

        thread.start();
    }

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

    private final IBinder mBinder = new LocalBinder();
}

Answer 1

似乎您在绑定(bind)和取消绑定(bind)您的 Activity 到您的服务时遇到了一些问题。 我猜你没有取消绑定(bind)到该服务的 Activity ，所以在你的 Activity 停止/终止后你的服务停止工作并且由于 START_STICKY 它将由系统再次启动。 您应该在 onPause() 中取消绑定(bind) Activity ，并在服务的 onDestory 方法中断开套接字。