多线程——newFixedThreadPool线程池

Posted 2021-01-15 whx20100101

newFixedThreadPool线程池：

理解：

　　1.固定线程数的线程池。

　　2.通过Executors中的静态方法创建：

 　　   public static ExecutorService newFixedThreadPool(int nThreads)或者

  　　  public static ExecutorService newFixedThreadPool(int nThreads, ThreadFactory threadFactory)两种方式。

　　3.返回的是ExecutorService对象线程池，例如：ExecutorService executorService = Executors.newFixedThreadPool(10)。

例子：

/**
 * 线程池，实现Runnable接口
 * @author Administrator
 *
 */
public class ThreadPoolRunnable implements Runnable{
    public void run(){
        System.out.println(Thread.currentThread().getName()+"线程");
    }
}

/**
 * 实现Callable线程池
 * @author Administrator
 *
 */
public class ThreadPoolCallable implements Callable<String>{
    @Override
    public String call() throws Exception {
        System.out.println(Thread.currentThread().getName()+"开始执行Callable接口.......");
        return "线程执行完毕！";
    }
}

 

//线程池测试类
public class TestThreadPoolRunnable {
    public static void main(String[] args) throws InterruptedException, ExecutionException {
        threadRunnable(5, 10);
        threadCallable(3, 10);
    }

    /**
     * 实现Runnable接口线程池
     * 
     * @param a
     *            创建线程数量
     * @param b
     *            线程池总数
     * @throws InterruptedException
     * @throws ExecutionException
     */
    public static void threadRunnable(int a, int b) throws InterruptedException, ExecutionException {
        // 创建线程池
        ExecutorService executorService = Executors.newFixedThreadPool(b);
        for (int i = 0; i < a; i++) {
            // 从线程池中调用线程
            executorService.submit(new ThreadPoolRunnable());
        }
    }

    /**
     * 实现Callable线程池
     * 
     * @param a
     *            创建线程数
     * @param b
     *            线程池总数
     * @throws InterruptedException
     * @throws ExecutionException
     */
    public static void threadCallable(int a, int b) throws InterruptedException, ExecutionException {
        ExecutorService executorService = Executors.newFixedThreadPool(b);
        for (int i = 0; i < a; i++) {
            Future<String> s = executorService.submit(new ThreadPoolCallable());
            System.out.println(s.get());
        }
    }
}
结果：
pool-1-thread-1线程
pool-1-thread-3线程
pool-1-thread-2线程
pool-1-thread-5线程
pool-1-thread-4线程
pool-2-thread-1开始执行Callable接口.......
线程执行完毕！
pool-2-thread-2开始执行Callable接口.......
线程执行完毕！
pool-2-thread-3开始执行Callable接口.......
线程执行完毕！