线程池体系

线程池类图

|-Java.util.concurrent.Executor 负责线程的使用与调度的根接口

|-ExecutorService:Executor的子接口，线程池的主要接口

|-AbstractExecutorService:实现了ExecutorService接口，基本实现了ExecutorService其中声明的所有方法，另有添加其他方法

|-ThreadPoolExecutor:继承了AbstractExecutorService，主要的常用实现类

|-ScheduledExecutorService:继承了ExecutorService，负责线程调度的接口

|-ScheduledThreadPoolExecutor:继承了ThreadPoolExecutor同时实现了ScheduledExecutorService

Executor接口

public interface Executor {
    void execute(Runnable command);
}

ExecutorService接口

public interface ExecutorService extends Executor {
    void shutdown();
    List<Runnable> shutdownNow();
    boolean isShutdown();
    boolean isTerminated();
    boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException;
    Future<?> submit(Runnable task);    //实现无返回值的Runnable接口
    <T> Future<T> submit(Callable<T> task);   //实现有返回值的Callable接口
    <T> Future<T> submit(Runnable task, T result);  //实现无返回值的Runnable接口并自定义返回值
    <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks)throws InterruptedException;   
    <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks,long timeout, TimeUnit unit)throws InterruptedException;    
    <T> T invokeAny(Collection<? extends Callable<T>> tasks)throws InterruptedException, ExecutionException;    
    <T> T invokeAny(Collection<? extends Callable<T>> tasks,long timeout, TimeUnit unit)throws InterruptedException, ExecutionException, TimeoutException;
}

ScheduledExecutorService接口

package java.util.concurrent;
public interface ScheduledExecutorService extends ExecutorService {
    public ScheduledFuture<?> schedule(Runnable command,long delay, TimeUnit unit);
    public <V> ScheduledFuture<V> schedule(Callable<V> callable,long delay, TimeUnit unit);
    //以固定频率来执行线程任务，固定频率的含义就是可能设定的固定时间不足以完成线程任务，但是它不管，达到设定的延迟时间了就要执行下一次了
    public ScheduledFuture<?> scheduleAtFixedRate(Runnable command,long initialDelay,long period,TimeUnit unit);
    //以固定延迟（时间）来执行线程任务，它实际上是不管线程任务的执行时间的，每次都要把任务执行完成后再延迟固定时间后再执行下一次
    public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command,long initialDelay,long delay,TimeUnit unit);
}