创建自定义线程池推荐ThreadPoolExecutor

    public ThreadPoolExecutor(int corePoolSize, // 核心线程池大小
                              int maximumPoolSize, // 最大线程池
                              long keepAliveTime, // 没人用的时候保留的时间
                              TimeUnit unit, // 时间单位
                              BlockingQueue<Runnable> workQueue, // 阻塞队列
                              ThreadFactory threadFactory, // 线程工厂
                              RejectedExecutionHandler handler // 拒绝策略 ) {
        if (corePoolSize < 0 ||
            maximumPoolSize <= 0 ||
            maximumPoolSize < corePoolSize ||
            keepAliveTime < 0)
            throw new IllegalArgumentException();
        if (workQueue == null || threadFactory == null || handler == null)
            throw new NullPointerException();
        this.acc = System.getSecurityManager() == null ?
                null :
                AccessController.getContext();
        this.corePoolSize = corePoolSize;
        this.maximumPoolSize = maximumPoolSize;
        this.workQueue = workQueue;
        this.keepAliveTime = unit.toNanos(keepAliveTime);
        this.threadFactory = threadFactory;
        this.handler = handler;
    }

自定义线程池

import java.util.concurrent.Executors;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

public class ThreadDemo {
    public static void main(String[] args) {

        // 自定义线程池
        ThreadPoolExecutor threadPool = new ThreadPoolExecutor(
                3, // 核心线程池大小为3
                6, // 最大线程池为6,可以优化成CPU的核心数，Runtime.getRuntime().availableProcessors()
                2, // 没人用的时候保留的时间为2
                TimeUnit.SECONDS, // 时间单位为秒
                new LinkedBlockingQueue(3), // 阻塞队列大小为3
                Executors.defaultThreadFactory(), // 默认的线程工厂
                new ThreadPoolExecutor.AbortPolicy()); // 拒绝策略,有4中可以根据需求选择

        // 四种拒绝策略
        /*
            当最大核心线程满了,队列满了，下面4种拒绝策略会有不同的处理方式
            new ThreadPoolExecutor.AbortPolicy(); // 调用任务不处理，直接抛出异常
            new ThreadPoolExecutor.CallerRunsPolicy(); //  调用任务从哪里来去那里去，不会抛出异常
            new ThreadPoolExecutor.DiscardPolicy(); // 调用任务直接丢弃，不会抛出异常
            new ThreadPoolExecutor.DiscardOldestPolicy(); // 调用任务会和最早使用的线程竞争，不会抛出异常
        */

        for (int i = 1; i < 20; i++) {
            threadPool.execute(() -> {
                System.out.println("当前线程池名称：" + Thread.currentThread().getName());
            });
        }
    }
}

来源：狂神说Java

转载：https://www.kuangstudy.com/course?cid=1