我有一个 Controller
类和一个 Monitor
工作线程。
Controller 线程看起来像这样
public class ControllerA {
public void ControllerA(){
try{
doWork();
}
catch(OhNoException e){
//catch exception
}
public void doWork() throws OhNoException{
new Thread(new Runnable(){
public void run(){
//Needs to monitor resources of ControllerA,
//if things go wrong, it needs to throw OhNoException for its parent
}
}).start();
//do work here
}
}
这样的设置可行吗?如何向线程外部抛出异常?
最佳答案
How do I throw exception to the outside of the thread?
有几种方法可以做到这一点。您可以在线程上设置 UncaughtExceptionHandler
,或者您可以使用 ExecutorService.submit(Callable)
并使用从 Future.get() 中获取的异常
。
最简单的方法是使用ExecutorService
:
ExecutorService threadPool = Executors.newSingleThreadScheduledExecutor();
Future<Void> future = threadPool.submit(new Callable<Void>() {
public Void call() throws Exception {
// can throw OhNoException here
return null;
}
});
// you need to shut down the pool after submitting the last task
threadPool.shutdown();
try {
// this waits for your background task to finish, it throws if the task threw
future.get();
} catch (ExecutionException e) {
// this is the exception thrown by the call() which could be a OhNoException
Throwable cause = e.getCause();
if (cause instanceof OhNoException) {
throw (OhNoException)cause;
} else if (cause instanceof RuntimeException) {
throw (RuntimeException)cause;
}
}
如果你想使用 UncaughtExceptionHandler
那么你可以这样做:
Thread thread = new Thread(...);
final AtomicReference throwableReference = new AtomicReference<Throwable>();
thread.setUncaughtExceptionHandler(new UncaughtExceptionHandler() {
public void uncaughtException(Thread t, Throwable e) {
throwableReference.set(e);
}
});
thread.start();
thread.join();
Throwable throwable = throwableReference.get();
if (throwable != null) {
if (throwable instanceof OhNoException) {
throw (OhNoException)throwable;
} else if (throwable instanceof RuntimeException) {
throw (RuntimeException)throwable;
}
}
关于java - 嵌套线程可以为父线程抛出异常吗?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/12897112/