Question

我的main方法打开一个应用程序并在执行完成后将running设置为false，唯一的问题是我只想在打开的应用程序关闭后将running设置为false。有没有简单的方法呢？

这是我的代码：

Runtime runtime = Runtime.getRuntime();
boolean running = true;
try {
    Process p = runtime.exec("open test.app");
    p.waitFor();
} catch (InterruptedException e) {}
running = false;

编辑：目前发生的事情是它打开test.app，然后即使应用仍在运行，它也会将running设置为false。

Answer 1

/**
 * Detects when a process is finished and invokes the associated listeners.
 */
public class ProcessExitDetector extends Thread {

    /** The process for which we have to detect the end. */
    private Process process;
    /** The associated listeners to be invoked at the end of the process. */
    private List<ProcessListener> listeners = new ArrayList<ProcessListener>();

    /**
     * Starts the detection for the given process
     * @param process the process for which we have to detect when it is finished
     */
    public ProcessExitDetector(Process process) {
        try {
            // test if the process is finished
            process.exitValue();
            throw new IllegalArgumentException("The process is already ended");
        } catch (IllegalThreadStateException exc) {
            this.process = process;
        }
    }

    /** @return the process that it is watched by this detector. */
    public Process getProcess() {
        return process;
    }

    public void run() {
        try {
            // wait for the process to finish
            process.waitFor();
            // invokes the listeners
            for (ProcessListener listener : listeners) {
                listener.processFinished(process);
            }
        } catch (InterruptedException e) {
        }
    }

    /** Adds a process listener.
     * @param listener the listener to be added
     */
    public void addProcessListener(ProcessListener listener) {
        listeners.add(listener);
    }

    /** Removes a process listener.
     * @param listener the listener to be removed
     */
    public void removeProcessListener(ProcessListener listener) {
        listeners.remove(listener);
    }
}

像这样使用：

...
processExitDetector = new ProcessExitDetector(program);
processExitDetector .addProcessListener(new ProcessListener() {
    public void processFinished(Process process) {
        System.out.println("The program has finished.");
    }
});
processExitDetector.start();

<强>来源（S）： Detecting Process Exit in Java

Answer 2

似乎open启动应用并退出。所以你仍然看到正在运行的东西，java看到这个过程完成了。我猜你是在MacOS上做的。我自己从未触摸过Mac，但open命令的文档说明您需要通过-W选项强制open等待应用终止：Process p = runtime.exec("open -W test.app");

Answer 3

我希望每当我打开用net bean制作的应用程序时，都从我离开的地方开始，或者从上次登录的帐户开始。就像我们登录Facebook并保持登录状态，即使我们关闭该应用程序也是如此我们重新启动应用程序，看到已经登录。

java - 如何打开程序并检测程序何时关闭

3 个答案: