Java學(xué)習(xí)

public class TrackingThreadPool extends ThreadPoolExecutor {

private final Map<Runnable, Boolean> inProgress

= new ConcurrentHashMap<Runnable,Boolean>();

private final ThreadLocal<Long> startTime = new ThreadLocal<Long>();

private long totalTime;

private int totalTasks;

public TrackingThreadPool(int corePoolSize, int maximumPoolSize, long keepAliveTime,

TimeUnit unit, BlockingQueue<Runnable> workQueue) {

super(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue);

}

protected void beforeExecute(Thread t, Runnable r) {

super.beforeExecute(t, r);

inProgress.put(r, Boolean.TRUE);

startTime.set(new Long(System.currentTimeMillis()));

}

protected void afterExecute(Runnable r, Throwable t) {

long time = System.currentTimeMillis() - startTime.get().longValue();

synchronized (this) {

totalTime += time;

++totalTasks;

}

inProgress.remove(r);

super.afterExecute(r, t);

}

public Set<Runnable> getInProgressTasks() {

return Collections.unmodifiableSet(inProgress.keySet());

}

public synchronized int getTotalTasks() {

return totalTasks;

}

public synchronized double getAverageTaskTime() {

return (totalTasks == 0) ? 0 : totalTime / totalTasks;

}

}

public class ThreadPoolStatus implements ThreadPoolStatusMBean {

private final TrackingThreadPool pool;

public ThreadPoolStatus(TrackingThreadPool pool) {

this.pool = pool;

}

public int getActiveThreads() {

return pool.getPoolSize();

}

public int getActiveTasks() {

return pool.getActiveCount();

}

public int getTotalTasks() {

return pool.getTotalTasks();

}

public int getQueuedTasks() {

return pool.getQueue().size();

}

public double getAverageTaskTime() {

return pool.getAverageTaskTime();

}

public String[] getActiveTaskNames() {

return toStringArray(pool.getInProgressTasks());

}

public String[] getQueuedTaskNames() {

return toStringArray(pool.getQueue());

}

private String[] toStringArray(Collection<Runnable> collection) {

ArrayList<String> list = new ArrayList<String>();

for (Runnable r : collection)

list.add(r.toString());

return list.toArray(new String[0]);

}

}