你可以使用
PriorityBlockingQueue 来指定 ThreadPoolExecutor 中的队列。
public class PriorityExecutor extends ThreadPoolExecutor {
public PriorityExecutor(int corePoolSize, int maximumPoolSize,
long keepAliveTime, TimeUnit unit, BlockingQueue<Runnable> workQueue) {
super(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue);
}
public static ExecutorService newFixedThreadPool(int nThreads) {
return new PriorityExecutor(nThreads, nThreads, 0L,
TimeUnit.MILLISECONDS, new PriorityBlockingQueue<Runnable>());
}
public Future<?> submit(Runnable task, int priority) {
return super.submit(new ComparableFutureTask(task, null, priority));
}
public void execute(Runnable command, int priority) {
super.execute(new ComparableFutureTask(command, null, priority));
}
}
定义ComparableFutureTask
按照优先级进行比较。
class ComparableFutureTask<T> extends FutureTask<T>
implements
Comparable<ComparableFutureTask<T>> {
volatile int priority = 0;
public ComparableFutureTask(Runnable runnable, T result, int priority) {
super(runnable, result);
this.priority = priority;
}
public ComparableFutureTask(Callable<T> callable, int priority) {
super(callable);
this.priority = priority;
}
@Override
public int compareTo(ComparableFutureTask<T> o) {
return Integer.valueOf(priority).compareTo(o.priority);
}
}
newTaskFor
会将ComparableFutureTask
包装成一个不可比较的FutureTask
。你还需要重写这两个newTaskFor
方法。 - assylias