Java Socket.Connect不会抛出异常

Question

我的代码检查给定代理是否正常工作并返回类型。在我检查代理是否为HTTP的函数中，如果代理已死，Socket.Connect方法不会抛出任何异常。 此函数由CachedThreadPool中的ExecutorService执行。 这是功能：

private CheckResponse checkHttp(MyProxy p) {

    try {

        SocketAddress addr = new InetSocketAddress(p.getIp(), p.getPort());
        Proxy proxy = new java.net.Proxy(java.net.Proxy.Type.HTTP, addr);
        Socket socket = new Socket(proxy);

        long startTime = System.currentTimeMillis();
        socket.connect(ProxyChecker.dest, Data.CHECK_TIMEOUT);  
        long elapsedTime = System.currentTimeMillis() - startTime;

        socket.close();

        return new CheckResponse(false, elapsedTime);

    } catch (Exception e) {

        e.printStackTrace();

        return new CheckResponse(true, 0);

    }

}

调试我发现程序在socket.connect方法之后进入ThreadPoolExecutor类的runWorker方法并永远循环。

final void runWorker(Worker w) {
    Thread wt = Thread.currentThread();
    Runnable task = w.firstTask;
    w.firstTask = null;
    w.unlock(); // allow interrupts
    boolean completedAbruptly = true;
    try {
        while (task != null || (task = getTask()) != null) {
            w.lock();
            // If pool is stopping, ensure thread is interrupted;
            // if not, ensure thread is not interrupted.  This
            // requires a recheck in second case to deal with
            // shutdownNow race while clearing interrupt
            if ((runStateAtLeast(ctl.get(), STOP) ||
                 (Thread.interrupted() &&
                  runStateAtLeast(ctl.get(), STOP))) &&
                !wt.isInterrupted())
                wt.interrupt();
            try {
                beforeExecute(wt, task);
                Throwable thrown = null;
                try {
                    task.run();
                } catch (RuntimeException x) {
                    thrown = x; throw x;
                } catch (Error x) {
                    thrown = x; throw x;
                } catch (Throwable x) {
                    thrown = x; throw new Error(x);
                } finally {
                    afterExecute(task, thrown);
                }
            } finally {
                task = null;
                w.completedTasks++;
                w.unlock();
            }
        }
        completedAbruptly = false;
    } finally {
        processWorkerExit(w, completedAbruptly);
    }
}

没有抛出异常，我无法解决问题。为什么呢？