自定义线程池实现

package com.jy.rental.thread;

import com.jy.rental.service.impl.AlipayPayServiceImpl;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Locale;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * @author nanzhou
 * @datetime 2019/3/4 上午10:40
 * @description: 自定义线程池
 * @since JDK 1.8
 */
public class CustomThreadPoolExecutor {

    /**
     * Logger
     */
    private static final Logger logger = LoggerFactory.getLogger(AlipayPayServiceImpl.class);
    /**
     * 获取活跃的 cpu数量
     */
    private static int NUMBER_OF_CORES = Runtime.getRuntime().availableProcessors();

    /**
     * 保存待执行任务的阻塞队列
     */
    private final static BlockingQueue CUSTOM_WORK_QUEUE;

    /**
     * 核心池以外的线程存活时间
     */
    private final static long KEEP_ALIVE_TIME = 10L;

    /**
     * 核心池以外的线程存活时间单位
     */
    private final static TimeUnit KEEP_ALIVE_TIME_UNIT = TimeUnit.SECONDS;

    /**
     * 自定义线程工厂
     */
    private static ThreadFactory CUSTOM_THREAD_FACTORY;

    /**
     * 饱和策略
     */
    private static RejectedExecutionHandler CUSTOM_REJECTED_EXECUTION_HANDLER;


    static {
        CUSTOM_WORK_QUEUE = new LinkedBlockingQueue<>();
        CUSTOM_THREAD_FACTORY = new NamedThreadFactory();
        CUSTOM_REJECTED_EXECUTION_HANDLER = new ThreadPoolExecutor.CallerRunsPolicy();
    }

    public static void execute(Runnable runnable) {
        if (runnable == null) {
            return;
        }
        /**
         * 1.当线程池小于 corePoolSize 时，新提交任务将创建一个新线程执行任务，即使此时线程池中存在空闲线程。
         * 2.当线程池达到 corePoolSize 时，新提交任务将被放入 workQueue 中，等待线程池中任务调度执行
         * 3.当 workQueue 已满，且 maximumPoolSize > corePoolSize时，新提交任务会创建新线程执行任务
         * 4.当提交任务数超过 maximumPoolSize 时，新提交任务由 RejectedExecutionHandler 处理
         * 5.当线程池中超过 corePoolSize 线程，空闲时间达到 keepAliveTime 时，关闭空闲线程
         * 6.当设置 allowCoreThreadTimeOut(true) 时，线程池中 corePoolSize 线程空闲时间达到 keepAliveTime 也将关闭
         * maximumPoolSize 推荐取值
         * 如果是 CPU 密集型任务，就需要尽量压榨CPU，参考值可以设为 NUMBER_OF_CORES + 1 或 NUMBER_OF_CORES + 2
         * 如果是 IO 密集型任务，参考值可以设置为 NUMBER_OF_CORES * 2
         **/
        ExecutorService executorService = new ThreadPoolExecutor(NUMBER_OF_CORES,
                NUMBER_OF_CORES * 2, KEEP_ALIVE_TIME, KEEP_ALIVE_TIME_UNIT,
                CUSTOM_WORK_QUEUE, CUSTOM_THREAD_FACTORY, CUSTOM_REJECTED_EXECUTION_HANDLER);
        executorService.execute(runnable);
    }


    private static class NamedThreadFactory implements ThreadFactory {
        private final AtomicInteger threadNumberAtomicInteger = new AtomicInteger(1);

        @Override
        public Thread newThread(Runnable r) {
            Thread thread = new Thread(r, String.format(Locale.CHINA, "%s%d", "CustomThreadFactory", threadNumberAtomicInteger.getAndIncrement()));
            logger.info("CurrentThread : " + "ThreadName" + thread.getName());
            return thread;
        }
    }
}