java，在键盘扫描程序不接收输入时创建循环

我试图在未收到keyboardscanner.nextline（）时进行循环。我被困在这里，因为我找不到解决方案，我甚至不知道这是否可能。。。下面是我在代码中尝试做的事情

public String messagingread(String username) throws RemoteException {
    Scanner keyboardScanner = new Scanner(System.in);
        try {
            while (keyboardScanner.nextLine().isEmpty) {
                System.out.println("cant get in here");
      //i can only get in here if the scann is only an enter(isempty), but i //want to get in here if i dont scan anything...i dont want isempty i want not //defined and i dont know how to do it ....
                }
            System.out.println("pls help")
            }       
        }  

---

这将在其他线程中执行任务并接受输入，直到输入为空。另外，请注意关闭

扫描仪

class Task implements Runnable {

    private boolean shouldRun = true;

    public void stop() {
        this.shouldRun = false;
    }

    @Override
    public void run() {
        while (this.shouldRun) {
            try {
                Thread.sleep(1000);
                System.out.println("Doing some work every 1 second ...");
            } catch (InterruptedException e) {
                 e.printStackTrace();
            }
        }
        System.out.println("Task have been stopped, Bye!");
        Thread.currentThread().interrupt();
    }
}

 public final class Example {

     public static void main(String[] args) {
         Scanner keyboardScanner = new Scanner(System.in);
         try {
             Task task = new Task();
             // run the task on new Thread
             Thread newThread = new Thread(task);
             newThread.start();
         /*
          read lines while it is not empty:
          (line = keyboardScanner.nextLine()) -> assign the input to line
          !(line ...).isEmpty() -> checks that line is not empty
           */
            System.out.println("Give me inputs");
            String line;
            while (!(line = keyboardScanner.nextLine()).isEmpty()) {
                System.out.println("new line read :" + line);
            }
            // when you give an empty line the while will stop then we stop
            // the task
            task.stop();
        } finally {
            // after the piece of code inside the try statement have finished
            keyboardScanner.close();
        }
        System.out.println("Empty line read. Bye!");
    }
}

---

这将在其他线程中执行任务并接受输入，直到输入为空。另外，请注意关闭

扫描仪

class Task implements Runnable {

    private boolean shouldRun = true;

    public void stop() {
        this.shouldRun = false;
    }

    @Override
    public void run() {
        while (this.shouldRun) {
            try {
                Thread.sleep(1000);
                System.out.println("Doing some work every 1 second ...");
            } catch (InterruptedException e) {
                 e.printStackTrace();
            }
        }
        System.out.println("Task have been stopped, Bye!");
        Thread.currentThread().interrupt();
    }
}

 public final class Example {

     public static void main(String[] args) {
         Scanner keyboardScanner = new Scanner(System.in);
         try {
             Task task = new Task();
             // run the task on new Thread
             Thread newThread = new Thread(task);
             newThread.start();
         /*
          read lines while it is not empty:
          (line = keyboardScanner.nextLine()) -> assign the input to line
          !(line ...).isEmpty() -> checks that line is not empty
           */
            System.out.println("Give me inputs");
            String line;
            while (!(line = keyboardScanner.nextLine()).isEmpty()) {
                System.out.println("new line read :" + line);
            }
            // when you give an empty line the while will stop then we stop
            // the task
            task.stop();
        } finally {
            // after the piece of code inside the try statement have finished
            keyboardScanner.close();
        }
        System.out.println("Empty line read. Bye!");
    }
}

---

谢谢你的回答，但我仍然有同样的问题，当我做键盘扫描时。nextLine（）我在等待输入，但我不想等待我想做一个循环，直到我做一个input@RuiAntunes我已经更新了我的答案。现在我包括了一个新的

线程

，它将在main接受输入时工作。当收到空输入时，所有工作都将停止。谢谢你的回答，但当我使用键盘扫描仪时，我仍然有相同的问题。nextLine（）我正在等待输入，但我不想等待，我想循环，直到我完成输入input@RuiAntunes我已经更新了我的答案。现在我包括了一个新的

线程

，它将在main接受输入时工作。当收到一个空输入时，所有工作都将停止。谢谢你的回答，但当我使用键盘扫描仪时，我仍然有相同的问题。nextLine（）我正在等待输入，但我不想等待我想循环直到我输入谢谢你的回答，但我仍然有相同的问题，当我做keyboardScanner.nextLine（）时，我在等待输入，但我不想等待，我想在输入之前循环