Java native process timeout

Question

At the moment I execute a native process using the following:

java.lang.Process process = Runtime.getRuntime().exec(command);  int returnCode = process.waitFor(); 

Suppose instead of waiting for the program to return I wish to terminate if a certain amount of time has elapsed. How do I do this?

Answer 1

All other responses are correct but it can be made more robust and efficient using FutureTask.

For example,

private static final ExecutorService THREAD_POOL      = Executors.newCachedThreadPool();  private static <T> T timedCall(Callable<T> c, long timeout, TimeUnit timeUnit)     throws InterruptedException, ExecutionException, TimeoutException {     FutureTask<T> task = new FutureTask<T>(c);     THREAD_POOL.execute(task);     return task.get(timeout, timeUnit); }  final java.lang.Process[] process = new Process[1]; try {     int returnCode = timedCall(new Callable<Integer>() {         public Integer call() throws Exception {             process[0] = Runtime.getRuntime().exec(command);              return process[0].waitFor();         }     }, timeout, TimeUnit.SECONDS); } catch (TimeoutException e) {     process[0].destroy();     // Handle timeout here } 

If you do this repeatedly, the thread pool is more efficient because it caches the threads.

Answer 2

If you're using Java 8 or later (API 26 or later for Android) you could simply use the waitFor with timeout:

Process p = ... if(!p.waitFor(1, TimeUnit.MINUTE)) {     //timeout - kill the process.      p.destroy(); // consider using destroyForcibly instead }