java - 如何异步调用java方法？

Question

是否有任何好的示例可以开始使用 java 同步方法调用。我有两个方法 a 和 b 并且必须异步调用 b 。有什么建议吗？

Answer 1

This is a big topic, with lots of gotchas. But you can get a good start by wrapping your method in a Callable<T> and submitting that to ExecutorService.submit. That will return back a Future<T>, which has a method get(). That last method returns T, but not until the Callable<T> finished.

For instance, let's say foo.b() returns String. You'd do something like:

Callable<String> asyncB = new Callable<String>() {
    @Override
    public String call() {
        foo.b();
    }
};
Future<String> futureB = myExecutorService.submit(asyncB);
// asyncB will now execute on a separate thread,
// which is managed by the ExecutorService
foo.a(); // synchronous call
String resultB = futureB.get();

If you're on Java 8, that first bit can just be:

Callable<String> asyncB = () -> foo.b();

Answer 2

如果您有任何机会使用 Spring，它们具有出色的异步支持。

http://docs.spring.io/spring/docs/3.0.x/reference/scheduling.html