Java线程与线程池

• • java线程创建方式
  • 线程池体系
  • Executor
  • ExecutorService
  • AbstractExecutorService

• 继承thread
• 实现runable接口
• 实现callable和future

抽象出定义一个执行无返回值的任务方法

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

抽象出定义了线程池的动作

public interface ExecutorService extends Executor {
    //关闭
    void shutdown();

    List shutdownNow();
    
    boolean isShutdown();
   
    boolean isTerminated();

    boolean awaitTermination(long timeout, TimeUnit unit)  throws InterruptedException;
    //提交任务
     Future submit(Callable task);

     Future submit(Runnable task, T result);

    Future submit(Runnable task);
     //执行所有任务
     List> invokeAll(Collection> tasks) throws InterruptedException;

     List> invokeAll(Collection> tasks, long timeout, TimeUnit unit)  throws InterruptedException;
    //执行任一任务
     T invokeAny(Collection> tasks)  throws InterruptedException, ExecutionException;

     T invokeAny(Collection> tasks, long timeout, TimeUnit unit)throws InterruptedException, ExecutionException, TimeoutException;
}

使用模板方法抽象定义了一些线程池常用的方法，都会调用子类实现的execute(ftask)方法。

   public  Future submit(Callable task) {
        if (task == null) throw new NullPointerException();
        RunnableFuture ftask = newTaskFor(task);
        execute(ftask);
        return ftask;
    }
##  RunnableFuture ftask = newTaskFor(task);
 protected  RunnableFuture newTaskFor(Callable callable) {
        return new FutureTask(callable);
 }

FutureTask继承关系：

Future接口定义了一些获取结果的包装方法。

public interface Future {

	 boolean cancel(boolean mayInterruptIfRunning);
	 boolean isCancelled();
	 boolean isDone();
	 V get() throws InterruptedException, ExecutionException;
	 V get(long timeout, TimeUnit unit)
	        throws InterruptedException, ExecutionException, TimeoutException;
}