当我们通过submit提交任务到线程池，如果线程失败，我们怎么去捕获这个失败而抛出来的异常呢
方法1：通过调用返回对象 FutureTask的get方法**
FutureTask.get() will re-throw any exception thrown by the task as an ExecutorException
缺点：该方法是阻塞调用，会阻塞提交任务的线程
方法2：在提交的线程任务的 run() or call()使用 try{}catch{}Exceptoion{}进行处理
Executors.newCachedThreadPool().submit(new Callable<Integer>() {
@Override
public Integer call() throws Exception {
try {
int a = 1 / 0;
return 1;
} catch (Exception e) {
e.printStackTrace();
} finally {
//you can do something here，e.g. log execution
}
return 0;
}
});
方法3：改写ThreadPoolExecutor的afterExecute方法
方法示例来自jdk的ThreadPoolExecutor的afterExecute方法注释
class ExtendedExecutor extends ThreadPoolExecutor {
// ...
protected void afterExecute(Runnable r, Throwable t) {
super.afterExecute(r, t);
if (t == null && r instanceof Future<?>) {
try {
Object result = ((Future<?>) r).get();
} catch (CancellationException ce) {
t = ce;
} catch (ExecutionException ee) {
t = ee.getCause();
catch (InterruptedException ie) {
Thread.currentThread().interrupt(); // ignore/reset
}
}
if (t != null)
System.out.println(t);
}
}
参考资料：https://stackoverflow.com/questions/2554549/handling-exceptions-for-threadpoolexecutor
