背景
很多时候需要一些简单的异步操作,如果都是new Thread(),然后start的话会有很多线程
CompletableFuture.runAsync这个静态方法可以更加方便,而且使用线程池可以更加灵活
代码分析
runAsync 方法有两个重载的方法:
- 其中一个只有一个参数
Runnable runnable - 另外一个是有两个参数,多了一个可以手动配置线程池,而不是默认的线程池
public static CompletableFuture<Void> runAsync(Runnable runnable) {
return asyncRunStage(asyncPool, runnable);
}
public static CompletableFuture<Void> runAsync(Runnable runnable,
Executor executor) {
return asyncRunStage(screenExecutor(executor), runnable);
}
然后我们看静态内部类:
static final class AsyncRun extends ForkJoinTask<Void>
implements Runnable, AsynchronousCompletionTask {
CompletableFuture<Void> dep; Runnable fn;
AsyncRun(CompletableFuture<Void> dep, Runnable fn) {
this.dep = dep; this.fn = fn;
}
public final Void getRawResult() { return null; }
public final void setRawResult(Void v) {}
public final boolean exec() { run(); return true; }
public void run() {
CompletableFuture<Void> d; Runnable f;
if ((d = dep) != null && (f = fn) != null) {
dep = null; fn = null;
if (d.result == null) {
try {
f.run();
d.completeNull();
} catch (Throwable ex) {
d.completeThrowable(ex);
}
}
d.postComplete();
}
}
}
