java - 完全退出 Java 方法

Question

我的方法 checkConnection() 在 TimeLimiter 内调用 setPort()，如果该方法不存在，它会在 3 秒内退出调用方法完成的。这非常有效，并且在超出时间限制时会出现 com.google.common.util.concurrent.UncheckedTimeoutException 异常。然而，即使抛出此异常后，setPort 仍然运行，并且一旦完成，打开端口的 try 语句中的代码就会运行，但是一旦到达 Thread.sleep(100) 就会出现 InterruptedException被抛出，然后该方法退出。然而，这给我留下了一个开放的端口，这会导致问题。有没有办法一旦超过时间限制，call()方法中的所有代码都会停止？

 public static String checkConnection(final String comPort) {

        final String port = comPort;
        String result = null;

        TimeLimiter limiter = new SimpleTimeLimiter();
        try {

            result = limiter.callWithTimeout(new Callable<String>() {

                public String call() {

                    // Try to set serial port
                    String setPort = setPort(comPort);

                    // Check for any exceptions
                    if(setPort.contains("jssc.SerialPortException")) {

                        if(setPort.contains("Port busy")) {

                            return "Error: The port appears to be busy";

                        } else {

                            return "Error: Can't connect to port";

                        }

                    }

                    try {

                            // Port can't be accessed twice at the same time
                            synchronized(portLock) {

                                // Open port if not already opened
                                if(!serialPort.isOpened())
                                    serialPort.openPort();

                                // Sleep while response is being sent
                                Thread.sleep(300);

                                // Check for response
                                buffer = serialPort.readBytes(6);//Read 6 bytes from serial port

                                serialPort.closePort();

                            }

                        // Parse response as string
                        response = new String(buffer);

                    } catch (SerialPortException | InterruptedException e) {

                        System.out.println("Serial:: ping() :: Exception while pinging Noteu : " + e);

                        return "Error";

                    }

                    return response;

                }
              }, 3, TimeUnit.SECONDS, false);

        } catch (Exception e) {

            System.out.println("Serial:: checkConnection() :: Exception while calling ping : " + e);

        }

    } 



public static String setPort(String port) {

        synchronized(portLock) {

            try {

                System.out.println("Serial:: setPort() :: Opening Port...");

                serialPort = new SerialPort(port);

                if(!serialPort.isOpened())
                    serialPort.openPort();

                System.out.println("Serial:: setPort() :: Setting Params...");

                serialPort.setParams(SerialPort.BAUDRATE_9600, 
                        SerialPort.DATABITS_8,
                        SerialPort.STOPBITS_1,
                        SerialPort.PARITY_NONE);
                System.out.println("Setting Port3");

                serialPort.closePort();

                System.out.println("Serial:: setPort() :: Port Set...");

                return "Success";

            } catch (SerialPortException e) {

                System.out.println("Serial:: setPort() :: Exception at set Port : " + e.toString());

                return e.toString();

            }

        }

    }

Answer 1

你可以尝试一下这是否有效这是

的签名

callWithTimeout(Callable<T> callable,
                long timeoutDuration,
                TimeUnit timeoutUnit,
                boolean amInterruptible)

........
amInterruptible - whether to respond to thread interruption by aborting the operation and throwing InterruptedException; if false, the operation is allowed to complete or time out, and the current thread's interrupt status is re-asserted.

您将 amInterruptible 传递为 false。您可以尝试传递 true 并看看它是否有效。而且我强烈感觉 setPort 必须是可中断的。为此，正如用户 Scadge 所评论的，您需要提供其实现。无论如何，只是希望这个快速解决方案可能适合您