java 线程池常用方法

导入依赖

<dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.9</version>
        </dependency>

小例子

import com.google.common.util.concurrent.ThreadFactoryBuilder;

import java.util.concurrent.*;

/**
 * @author Mr_Lee
 * @date 2020-07-20 11:14
 */
public class ThreadPoolDemo {

    private static ExecutorService executorService = new ThreadPoolExecutor(9, 50, 0L, TimeUnit.MILLISECONDS, new ArrayBlockingQueue<Runnable>(1024) {
    }, new ThreadFactoryBuilder().setNameFormat("test1-pool-%d").build());

    /**
     * 可以这样创建当然我们建议上面的创建方式
     */
    public static void test0() {
        ExecutorService executorServiceOne = Executors.newSingleThreadExecutor();
        ExecutorService executorServiceTwo = Executors.newFixedThreadPool(9);
        ExecutorService executorServiceThree = Executors.newCachedThreadPool();
    }

    /**
     * 有返回值
     */
    public static void test1() throws ExecutionException, InterruptedException {

        Callable<Integer> one = () -> 1 + 1;
        Callable<Integer> two = () -> 1 + 2;
        Callable<Integer> three = () -> 1 + 3;

        FutureTask<Integer> oneTask = new FutureTask<>(one);
        FutureTask<Integer> twoTask = new FutureTask<>(two);
        FutureTask<Integer> threeTask = new FutureTask<>(three);

        executorService.submit(oneTask);
        executorService.submit(twoTask);
        executorService.submit(threeTask);

        //阻塞直到执行完成
        Integer integerOne = oneTask.get();
        Integer integerTwo = twoTask.get();
        Integer integerThree = threeTask.get();

        System.out.println(integerOne + integerTwo + integerThree);

    }

    /**
     * 有返回值
     */
    public static void test2() throws ExecutionException, InterruptedException {
        Callable<Integer> one = () -> 1 + 1;
        Callable<Integer> two = () -> 1 + 2;
        Callable<Integer> three = () -> 1 + 3;

        Future<Integer> oneFuture = executorService.submit(one);
        Future<Integer> twoFuture = executorService.submit(two);
        Future<Integer> threeFuture = executorService.submit(three);

        //阻塞直到执行完成
        Integer oneInteger = oneFuture.get();
        Integer twoInteger = twoFuture.get();
        Integer threeInteger = threeFuture.get();

        System.out.println(oneInteger + twoInteger + threeInteger);
    }

    /**
     * 无返回值
     */
    public static void test3() {
        Runnable one = () -> System.out.println(Thread.currentThread().getName());
        Runnable two = () -> System.out.println(Thread.currentThread().getName());
        Runnable three = () -> System.out.println(Thread.currentThread().getName());
        executorService.execute(one);
        executorService.execute(two);
        executorService.execute(three);
    }

    /**
     * 无返回值默认取值为null
     */
    public static void test4() throws ExecutionException, InterruptedException {
        Runnable one = () -> System.out.println(Thread.currentThread().getName());
        Runnable two = () -> System.out.println(Thread.currentThread().getName());
        Runnable three = () -> System.out.println(Thread.currentThread().getName());

        Future<?> oneFuture = executorService.submit(one);
        Future<?> twoFuture = executorService.submit(two);
        Future<?> threeFuture = executorService.submit(three);

        //阻塞直到执行完成
        Object oneObject = oneFuture.get();
        Object twoObject = twoFuture.get();
        Object threeObject = threeFuture.get();

        //null
        System.out.println(oneObject);
        System.out.println(twoObject);
        System.out.println(threeObject);
    }

    public static void test5() throws ExecutionException, InterruptedException {
        Runnable one = () -> System.out.println(Thread.currentThread().getName());
        Runnable two = () -> System.out.println(Thread.currentThread().getName());
        Runnable three = () -> System.out.println(Thread.currentThread().getName());

        Future<Integer> oneFuture = executorService.submit(one, 1 + 1);
        Future<Integer> twoFuture = executorService.submit(two, 1 + 2);
        Future<Integer> threeFuture = executorService.submit(three, 1 + 3);

        Integer oneInteger = oneFuture.get();
        Integer twoInteger = twoFuture.get();
        Integer threeInteger = threeFuture.get();

        System.out.println(oneInteger + twoInteger + threeInteger);
    }

    public static void main(String[] args) throws ExecutionException, InterruptedException {
//        test0();
//        test1();
//        test2();
//        test3();
//        test4();
//        test5();
    }


}