线程池有哪些配置参数，各自的作用是什么？

5大参数

a.核心线程数

b 最大线程数

c 线程空闲时间

d 阻塞队列大小：queueCapacity

e 任务拒绝处理器 ：rejectedExceptionHandler 

 

根据jdk 1.7,他又四类构造函数：

1. ThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit, BlockingQueue<Runnable> workQueue)

2. ThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit, BlockingQueue<Runnable> workQueue, RejectedExecutionHandler handler)

3. ThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit, BlockingQueue<Runnable> workQueue, ThreadFactory threadFactory)

4. ThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit, BlockingQueue<Runnable> workQueue, ThreadFactory threadFactory, RejectedExecutionHandler handler)

 

实现线程池，有四种策略：

 

1.newCachedThreadPool

jdk 1.6源码：

public static ExecutorService newCachedThreadPool() {

        return new ThreadPoolExecutor(0, Integer.MAX_VALUE,

                                      60L, TimeUnit. SECONDS,

                                      new SynchronousQueue<Runnable>());

    }

 

2 newFixedThreadPool

jdk 1.6源码：

    public static ExecutorService newFixedThreadPool(int nThreads) {

        return new ThreadPoolExecutor(nThreads, nThreads,

                                      0L, TimeUnit. MILLISECONDS,

                                      new LinkedBlockingQueue<Runnable>());

    }

 

3 newSingleThreadExecutor

jdk 1.6源码：

 public static ExecutorService newSingleThreadExecutor() {

        return new FinalizableDelegatedExecutorService

            ( new ThreadPoolExecutor(1, 1,

                                    0L, TimeUnit. MILLISECONDS,

                                    new LinkedBlockingQueue<Runnable>()));

    }

 

4 newScheduledThreadPool

jdk 1.6源码：

      

   public static ScheduledExecutorService newScheduledThreadPool (int corePoolSize) {

        return new ScheduledThreadPoolExecutor(corePoolSize);

    }

    public ScheduledThreadPoolExecutor( int corePoolSize) {

        super(corePoolSize, Integer.MAX_VALUE, 0, TimeUnit.NANOSECONDS,

              new DelayedWorkQueue());

    }