jdk自带的原生的拒绝策略抛出的异常信息不够详细，而dubbo对拒绝策略进行了改写，抛出的信息更具有参考价值，值得我们借鉴。

jdk自带的原生拒绝策略抛出的信息：

// ThreadPoolExecutor的toString方法

/**

* Returns a string identifying this pool, as well as its state,

* including indications of run state and estimated worker and

* task counts.

*

* @return a string identifying this pool, as well as its state

*/

public String toString() {

    long ncompleted;

    int nworkers, nactive;

    final ReentrantLock mainLock = this.mainLock;

    mainLock.lock();

    try {

        ncompleted = completedTaskCount;

        nactive = 0;

        nworkers = workers.size();

        for (Worker w : workers) {

            ncompleted += w.completedTasks;

            if (w.isLocked())

                ++nactive;

        }

    } finally {

        mainLock.unlock();

    }

    int c = ctl.get();

    String rs = (runStateLessThan(c, SHUTDOWN) ? "Running" :

                    (runStateAtLeast(c, TERMINATED) ? "Terminated" :

                    "Shutting down"));

    return super.toString() +

        "[" + rs +

        ", pool size = " + nworkers +

        ", active threads = " + nactive +

        ", queued tasks = " + workQueue.size() +

        ", completed tasks = " + ncompleted +

        "]";

}

dubbo的线程池的拒绝策略抛出的信息：

// com.alibaba.dubbo.common.threadpool.support.AbortPolicyWithReport

@Override

public void rejectedExecution(Runnable r, ThreadPoolExecutor e) {

    String msg = String.format("Thread pool is EXHAUSTED!" +

            " Thread Name: %s, Pool Size: %d (active: %d, core: %d, max: %d, largest: %d), Task: %d (completed: %d)," +

            " Executor status:(isShutdown:%s, isTerminated:%s, isTerminating:%s), in %s://%s:%d!" ,

            threadName, e.getPoolSize(), e.getActiveCount(), e.getCorePoolSize(), e.getMaximumPoolSize(), e.getLargestPoolSize(),

            e.getTaskCount(), e.getCompletedTaskCount(), e.isShutdown(), e.isTerminated(), e.isTerminating(),

            url.getProtocol(), url.getIp(), url.getPort());

    logger.warn(msg);

    throw new RejectedExecutionException(msg);

}