/**
* 异步调用 ，需要返回值，即使步调用Future.get方法，也会处理调用超时问题.
*
* @param callable
* @return 通过future.get()获取返回结果.
*/
@SuppressWarnings("unchecked")
public <T> Future<T> asyncCall(Callable<T> callable) {
try {
try {
setAttachment(Constants.ASYNC_KEY, Boolean.TRUE.toString());
final T o = callable.call();
// local调用会直接返回结果.
if (o != null) {
FutureTask<T> f =
new FutureTask<T>(
new Callable<T>() {
public T call() throws Exception {
return o;
}
});
f.run();
return f;
} else {
}
} catch (Exception e) {
throw new RpcException(e);
} finally {
removeAttachment(Constants.ASYNC_KEY);
}
} catch (final RpcException e) {
return new Future<T>() {
public boolean cancel(boolean mayInterruptIfRunning) {
return false;
}
public boolean isCancelled() {
return false;
}
public boolean isDone() {
return true;
}
public T get() throws InterruptedException, ExecutionException {
throw new ExecutionException(e.getCause());
}
public T get(long timeout, TimeUnit unit)
throws InterruptedException, ExecutionException, TimeoutException {
return get();
}
};
}
return ((Future<T>) getContext().getFuture());
}
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
System.out.print("Enter base directory (e.g. /usr/local/jdk5.0/src): ");
String directory = in.nextLine();
System.out.print("Enter keyword (e.g. volatile): ");
String keyword = in.nextLine();
MatchCounter counter = new MatchCounter(new File(directory), keyword);
FutureTask<Integer> task = new FutureTask<Integer>(counter);
Thread t = new Thread(task);
t.start();
try {
System.out.println(task.get() + " matching files.");
} catch (ExecutionException e) {
e.printStackTrace();
} catch (InterruptedException e) {
}
}