套接字服务onBackPressed

Question

当我按下系统后退按钮时，我的应用程序断开连接，但我想以这种方式返回：

  

i.setFlags（Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP）;

我认为我的Socket Service中存在错误，导致我对此产生疑问：

2018-11-16 11:54:45.869 6099-6099/com.app.ifarma I/SocketService: quit:
2018-11-16 11:54:45.871 6099-6099/com.app.ifarma W/System.err: java.net.SocketException: Socket is closed
2018-11-16 11:54:45.872 6099-6099/com.app.ifarma W/System.err:     at java.net.Socket.getInputStream(Socket.java:930)
2018-11-16 11:54:45.872 6099-6099/com.app.ifarma W/System.err:     at com.app.ifarma.SocketService.closeConnection(SocketService.java:126)
2018-11-16 11:54:45.872 6099-6099/com.app.ifarma W/System.err:     at com.app.ifarma.SocketService.sendMessage(SocketService.java:115)
2018-11-16 11:54:45.872 6099-6099/com.app.ifarma W/System.err:     at com.app.ifarma.Scollega$2.run(Scollega.java:71)
2018-11-16 11:54:45.872 6099-6099/com.app.ifarma W/System.err:     at android.os.Handler.handleCallback(Handler.java:789)
2018-11-16 11:54:45.872 6099-6099/com.app.ifarma W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:98)
2018-11-16 11:54:45.872 6099-6099/com.app.ifarma W/System.err:     at android.os.Looper.loop(Looper.java:164)
2018-11-16 11:54:45.872 6099-6099/com.app.ifarma W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:6541)
2018-11-16 11:54:45.872 6099-6099/com.app.ifarma W/System.err:     at java.lang.reflect.Method.invoke(Native Method)
2018-11-16 11:54:45.872 6099-6099/com.app.ifarma W/System.err:     at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
2018-11-16 11:54:45.873 6099-6099/com.app.ifarma W/System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
2018-11-16 11:54:45.886 6099-6134/com.app.ifarma W/System.err: java.net.SocketException: Socket closed
2018-11-16 11:54:45.886 6099-6134/com.app.ifarma W/System.err:     at java.net.SocketInputStream.socketRead0(Native Method)
2018-11-16 11:54:45.887 6099-6134/com.app.ifarma W/System.err:     at java.net.SocketInputStream.socketRead(SocketInputStream.java:114)
2018-11-16 11:54:45.887 6099-6134/com.app.ifarma W/System.err:     at java.net.SocketInputStream.read(SocketInputStream.java:170)
2018-11-16 11:54:45.887 6099-6134/com.app.ifarma W/System.err:     at java.net.SocketInputStream.read(SocketInputStream.java:139)
2018-11-16 11:54:45.887 6099-6134/com.app.ifarma W/System.err:     at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:288)
2018-11-16 11:54:45.889 6099-6134/com.app.ifarma W/System.err:     at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:351)
2018-11-16 11:54:45.894 6099-6134/com.app.ifarma W/System.err:     at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:180)
2018-11-16 11:54:45.898 6099-6134/com.app.ifarma W/System.err:     at java.io.InputStreamReader.read(InputStreamReader.java:184)
2018-11-16 11:54:45.899 6099-6134/com.app.ifarma W/System.err:     at java.io.BufferedReader.fill(BufferedReader.java:172)
2018-11-16 11:54:45.900 6099-6134/com.app.ifarma W/System.err:     at java.io.BufferedReader.readLine(BufferedReader.java:335)
2018-11-16 11:54:45.905 6099-6134/com.app.ifarma W/System.err:     at java.io.BufferedReader.readLine(BufferedReader.java:400)
2018-11-16 11:54:45.905 6099-6134/com.app.ifarma W/System.err:     at com.app.ifarma.SocketService$ClientThread.run(SocketService.java:272)
2018-11-16 11:54:45.906 6099-6134/com.app.ifarma W/System.err:     at java.lang.Thread.run(Thread.java:764)
2018-11-16 11:54:45.907 6099-6131/com.app.ifarma W/System.err: java.net.SocketException: Socket closed
2018-11-16 11:54:45.907 6099-6131/com.app.ifarma W/System.err:     at java.net.SocketInputStream.socketRead0(Native Method)
2018-11-16 11:54:45.908 6099-6131/com.app.ifarma W/System.err:     at java.net.SocketInputStream.socketRead(SocketInputStream.java:114)
2018-11-16 11:54:45.909 6099-6131/com.app.ifarma W/System.err:     at java.net.SocketInputStream.read(SocketInputStream.java:170)
2018-11-16 11:54:45.909 6099-6131/com.app.ifarma W/System.err:     at java.net.SocketInputStream.read(SocketInputStream.java:139)
2018-11-16 11:54:45.909 6099-6131/com.app.ifarma W/System.err:     at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:288)
2018-11-16 11:54:45.910 6099-6131/com.app.ifarma W/System.err:     at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:351)
2018-11-16 11:54:45.918 6099-6131/com.app.ifarma W/System.err:     at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:180)
2018-11-16 11:54:45.918 6099-6131/com.app.ifarma W/System.err:     at java.io.InputStreamReader.read(InputStreamReader.java:184)
2018-11-16 11:54:45.920 6099-6131/com.app.ifarma W/System.err:     at java.io.BufferedReader.fill(BufferedReader.java:172)
2018-11-16 11:54:45.920 6099-6131/com.app.ifarma W/System.err:     at java.io.BufferedReader.readLine(BufferedReader.java:335)
2018-11-16 11:54:45.921 6099-6131/com.app.ifarma W/System.err:     at java.io.BufferedReader.readLine(BufferedReader.java:400)
2018-11-16 11:54:45.922 6099-6131/com.app.ifarma W/System.err:     at com.app.ifarma.SocketService$ClientThread.run(SocketService.java:272)
2018-11-16 11:54:45.923 6099-6131/com.app.ifarma W/System.err:     at java.lang.Thread.run(Thread.java:764)
2018-11-16 11:54:45.977 6099-6099/com.app.ifarma I/SocketService: quit:
2018-11-16 11:54:45.978 6099-6099/com.app.ifarma W/System.err: java.lang.NullPointerException: Attempt to invoke virtual method 'java.io.OutputStream java.net.Socket.getOutputStream()' on a null object reference
2018-11-16 11:54:45.979 6099-6099/com.app.ifarma W/System.err:     at com.app.ifarma.SocketService.closeConnection(SocketService.java:125)
2018-11-16 11:54:45.979 6099-6099/com.app.ifarma W/System.err:     at com.app.ifarma.SocketService.sendMessage(SocketService.java:115)
2018-11-16 11:54:45.979 6099-6099/com.app.ifarma W/System.err:     at com.app.ifarma.Scollega$2.run(Scollega.java:71)
2018-11-16 11:54:45.980 6099-6099/com.app.ifarma W/System.err:     at android.os.Handler.handleCallback(Handler.java:789)
2018-11-16 11:54:45.980 6099-6099/com.app.ifarma W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:98)
2018-11-16 11:54:45.980 6099-6099/com.app.ifarma W/System.err:     at android.os.Looper.loop(Looper.java:164)
2018-11-16 11:54:45.980 6099-6099/com.app.ifarma W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:6541)
2018-11-16 11:54:45.980 6099-6099/com.app.ifarma W/System.err:     at java.lang.reflect.Method.invoke(Native Method)
2018-11-16 11:54:45.980 6099-6099/com.app.ifarma W/System.err:     at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
2018-11-16 11:54:45.981 6099-6099/com.app.ifarma W/System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)

这是我的socketService（问题部分）：

@Override
    public void onCreate() {
        super.onCreate();
    }

    public void sendMessage(String message) {

        line = "";

        if (out != null && !out.checkError()) {
            out.println(message);
            out.flush();
            Log.i("SocketService", "" + message.toString());
            //ci aspettiamo una risposta solo se non e' quit
            if (message.equals("quit:")) {
                closeConnection();
            }

        }
    }

    public void closeConnection() {

        try {
            connect = false;
            socket.getOutputStream().close();
            socket.getInputStream().close();
            socket.close();
        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }

        socket = null;
    }

也许我的“ scollega”课程也有问题

public class Scollega extends Activity {

    public SocketService s;
    //service
    boolean mBounded;
    ServiceConnection mConnection = new ServiceConnection() {

        public void onServiceDisconnected(ComponentName name) {
            mBounded = false;
            s = null;
        }

        public void onServiceConnected(ComponentName name, IBinder service) {
            mBounded = true;
            LocalBinder mLocalBinder = (LocalBinder) service;
            s = mLocalBinder.getServerInstance();
        }
    };

    ;

    @Override
    protected void onStart() {
        super.onStart();
        Intent mIntent = new Intent(this, SocketService.class);
        bindService(mIntent, mConnection, BIND_AUTO_CREATE);
    }

    @Override
    protected void onStop() {
        super.onStop();
        if (mBounded) {
            unbindService(mConnection);
            mBounded = false;
        }
    }

    ;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.loader);
        getWindow().setWindowAnimations(0);


        TextView outputView = (TextView) findViewById(R.id.textLoader);
        outputView.setText("Scollegamento...");

        //creiamo il timeout dopo l'avvio del servizio
        Handler handler = new Handler();
        handler.postDelayed(new Runnable() {

            @Override
            public void run() {

                try {
                    s.sendMessage("quit:");
                } catch (Exception e) {
                    e.printStackTrace();
                }


                //torniamo in Home
                Intent i = new Intent(Scollega.this, Home.class);
                i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
                startActivity(i);
                overridePendingTransition(R.anim.slide_left, R.anim.slide_right);
                finish();
            }
        }, 1000); // ritardiamo l'esecuzione di un secondo

    }

我从一个不想再处理它的人那里继承了这个程序，我解决了大多数问题，但是我不知道该怎么做...