Java多线程中的Executor详解

Executor executor = anExecutor;
executor.execute(new RunnableTask1());

 class DirectExecutor implements Executor {
   public void execute(Runnable r) {
     //直接执行提交者任务
     r.run();
   }
 }

 class ThreadPerTaskExecutor implements Executor {
   public void execute(Runnable r) {
     //创建新线程来执行任务
     new Thread(r).start();
   }
 }

class SerialExecutor implements Executor {
   final Queue<Runnable> tasks = new ArrayDeque<Runnable>();
   final Executor executor;
   Runnable active;
 
   SerialExecutor(Executor executor) {
     this.executor = executor;
   }
 
   public synchronized void execute(final Runnable r) {
     //创建一个任务并存放到双端队列
     tasks.offer(new Runnable() {
       public void run() {
         try {
           r.run();
         } finally {
           scheduleNext();
         }
       }
     });
     //开启第一个任务
     if (active == null) {
       scheduleNext();
     }
   }
 
  
   protected synchronized void scheduleNext() {
     if ((active = tasks.poll()) != null) {
       executor.execute(active);
     }
   }
 }