Java线程池ExecutorService

// 创建可以容纳3个线程的线程池  
ExecutorService fixedThreadPool = Executors.newFixedThreadPool(3);  
  
public static ExecutorService newFixedThreadPool(int nThreads) {  
        return new ThreadPoolExecutor(nThreads, //core pool size  
                                      nThreads, //maximum pool size  
                                      0L,       //keep alive time  
                                      TimeUnit.MILLISECONDS,  
                                      new LinkedBlockingQueue<Runnable>());  
}  

// 线程池的大小会根据执行的任务数动态分配  
ExecutorService cachedThreadPool = Executors.newCachedThreadPool();  
  
public static ExecutorService newCachedThreadPool() {  
    return new ThreadPoolExecutor(0,                 //core pool size  
                                  Integer.MAX_VALUE, //maximum pool size  
                                  60L,               //keep alive time  
                                  TimeUnit.SECONDS,  
                                  new SynchronousQueue<Runnable>());  
}  

// 创建单个线程的线程池，如果当前线程在执行任务时突然中断，则会创建一个新的线程替代它继续执行任务    
ExecutorService singleThreadPool = Executors.newSingleThreadExecutor();  
  
public static ExecutorService newSingleThreadExecutor() {  
        return new FinalizableDelegatedExecutorService  
            (new ThreadPoolExecutor(1,  //core pool size  
                                    1,  //maximum pool size  
                                    0L, //keep alive time  
                                    TimeUnit.MILLISECONDS,  
                                    new LinkedBlockingQueue<Runnable>()));  
}  

// 效果类似于Timer定时器  
ScheduledExecutorService scheduledThreadPool = Executors.newScheduledThreadPool(3);  
  
public ScheduledThreadPoolExecutor(int corePoolSize) {  
        super(corePoolSize,      //core pool size  
              Integer.MAX_VALUE, //maximum pool size  
              0,                 //keep alive time  
              TimeUnit.NANOSECONDS,  
              new DelayedWorkQueue());  
}