JAVA 之线程池定义

@Slf4j
@Configuration
@EnableAsync
public class ExecutorConfig {

    @Bean
    public Executor asyncCopyServiceExecutor() {
        log.info("start async copy from ops to dest container Executor......");
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        //配置核心线程数
        executor.setCorePoolSize(10);
        //配置最大线程数
        executor.setMaxPoolSize(10);
        //配置队列大小
        executor.setQueueCapacity(5000);
        //配置线程池中的线程的名称前缀
        executor.setThreadNamePrefix("async-copy-service-");

        // rejection-policy：当pool已经达到max size的时候，如何处理新任务
        // CALLER_RUNS：不在新线程中执行任务，而是有调用者所在的线程来执行
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        //执行初始化
        executor.initialize();
        return executor;
    }
}

定义线程池的几种方式

package com.example.chaoming.exercise.jdk.juc;

import com.google.common.util.concurrent.ThreadFactoryBuilder;
import org.junit.Test;

import java.util.concurrent.*;

import static java.util.concurrent.TimeUnit.NANOSECONDS;

/**
 * 线程池的创建与定义
 */
public class ThreadPoolTest {


    /**
     * 创建cache线程池
     */
    @Test
    public void createNewCachedThreadPool () {
        // 无界线程池
        ExecutorService executorService = Executors.newCachedThreadPool();
        // 构造器
        new ThreadPoolExecutor(0, Integer.MAX_VALUE,
                60L, TimeUnit.SECONDS,
                new SynchronousQueue<Runnable>());
    }

    /**
     * 创建Fixed线程池
     */
    @Test
    public void createNewFixedThreadPool () {
        // 固定长度线程池
        ExecutorService executorService1 = Executors.newFixedThreadPool(100);
        // 构造器
        new ThreadPoolExecutor(100, 100,
                0L, TimeUnit.MILLISECONDS,
                new LinkedBlockingQueue<Runnable>());
    }


    /**
     * 创建Fixed线程池
     */
    @Test
    public void createNewSingleThreadExecutor () {
        // 固定长度线程池
        ExecutorService executorService1 = Executors.newSingleThreadExecutor();
        // 构造器
        // 思考一下  keepAlivetime = 0 ？？？会怎样
        new ThreadPoolExecutor(1, 1,
                0L, TimeUnit.MILLISECONDS,
                new LinkedBlockingQueue<Runnable>());
    }


    /**
     * 创建Fixed线程池
     */
    @Test
    public void createNewScheduledThreadPool () {
        // 固定长度线程池
        ExecutorService executorService1 = Executors.newScheduledThreadPool(5);
        // 构造器
//        super(5, Integer.MAX_VALUE, 0, NANOSECONDS,
//                new ScheduledThreadPoolExecutor.DelayedWorkQueue());
    }


    private ExecutorService spiderExecutor = new ThreadPoolExecutor(Runtime.getRuntime().availableProcessors() * 2
            , Runtime.getRuntime().availableProcessors() * 10
            //当线程数大于核心时，多于的空闲线程最多存活时间
            , 0
            , TimeUnit.SECONDS
            //无界阻塞队列，当添加速度大于移除速度会内存溢出
            , new LinkedBlockingQueue<>(1024)
            // 定义线程名称
            , new ThreadFactoryBuilder().setNameFormat("spider-pool-%d").build()
            , new ThreadPoolExecutor.AbortPolicy());


}