使用Process.waitFor（）和java.lang.InterruptedException的Java多线程

Question

This is the pseudocode of what I have been doing:

ProcessBuilder processBuilder = new ProcessBuilder(cmdToExecute);
    Process process = processBuilder.start();
    StreamGobbler errorGobbler = new StreamGobbler(process.getErrorStream(), "ERROR");
    StreamGobbler outStreamGobbler = new StreamGobbler(process.getInputStream(), "OUTPUT");

    errorGobbler.start();
    outStreamGobbler.start();
    int exitValue = process.waitFor();
    process.destroy();

I am getting InterruptedException while using

Process.waitFor()

command. It was fine when it was a single threaded java app. But now its a multithreaded app, I am getting

java.lang.InterruptedException

on that particulat line. Java doc says:

Throws: InterruptedException - if the current thread is interrupted by another thread while it is waiting, then the wait is ended and an InterruptedException is thrown

I understand what it means because 1 thread might be waiting while another wants to wait too but how do I get over this exception and also I will be able to use waitFor().

Any help is appreaciated. I didn't find necessary to post the code, but let me know if you guys need it.

Code for ExecutorService:

while(...){
                          .......
        execServ.execute(...);
    }
    execServ.shutdown();
            while(!execServ.isTerminated()){
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
                }

Answer 1

I'm not sure you understand what the Javadoc means. It is saying that if some other thread calls interrupt() on the thread that is executing the code you posted before or during its call of waitFor() , an InterruptedException will be thrown. It has nothing to do with two threads waiting for something at the same time.

Does your program explicitly call interrupt() anywhere? Alternatively, are you executing this process through an ExecutorService ? When you cancel a task that has been submitted to an executor, it may be interrupted.