ThreadPoolExecutor参数详解

 1 /**
 2      * Creates a new {@code ThreadPoolExecutor} with the given initial
 3      * parameters.
 4      *
 5      * @param corePoolSize the number of threads to keep in the pool, even
 6      *        if they are idle, unless {@code allowCoreThreadTimeOut} is set
 7      * @param maximumPoolSize the maximum number of threads to allow in the
 8      *        pool
 9      * @param keepAliveTime when the number of threads is greater than
10      *        the core, this is the maximum time that excess idle threads
11      *        will wait for new tasks before terminating.
12      * @param unit the time unit for the {@code keepAliveTime} argument
13      * @param workQueue the queue to use for holding tasks before they are
14      *        executed.  This queue will hold only the {@code Runnable}
15      *        tasks submitted by the {@code execute} method.
16      * @param threadFactory the factory to use when the executor
17      *        creates a new thread
18      * @param handler the handler to use when execution is blocked
19      *        because the thread bounds and queue capacities are reached
20      * @throws IllegalArgumentException if one of the following holds:<br>
21      *         {@code corePoolSize < 0}<br>
22      *         {@code keepAliveTime < 0}<br>
23      *         {@code maximumPoolSize <= 0}<br>
24      *         {@code maximumPoolSize < corePoolSize}
25      * @throws NullPointerException if {@code workQueue}
26      *         or {@code threadFactory} or {@code handler} is null
27      */
28     public ThreadPoolExecutor(int corePoolSize,
29                               int maximumPoolSize,
30                               long keepAliveTime,
31                               TimeUnit unit,
32                               BlockingQueue<Runnable> workQueue,
33                               ThreadFactory threadFactory,
34                               RejectedExecutionHandler handler) {
35         if (corePoolSize < 0 ||
36             maximumPoolSize <= 0 ||
37             maximumPoolSize < corePoolSize ||
38             keepAliveTime < 0)
39             throw new IllegalArgumentException();
40         if (workQueue == null || threadFactory == null || handler == null)
41             throw new NullPointerException();
42         this.corePoolSize = corePoolSize;
43         this.maximumPoolSize = maximumPoolSize;
44         this.workQueue = workQueue;
45         this.keepAliveTime = unit.toNanos(keepAliveTime);
46         this.threadFactory = threadFactory;
47         this.handler = handler;
48     }