一、线程池配置

1、ThreadPoolConfig

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import java.util.concurrent.Executor;
import java.util.concurrent.ThreadPoolExecutor;

@Configuration
public class ThreadPoolConfig {

    private final static int AVAILABLE_PROCESSOR = Runtime.getRuntime().availableProcessors();

    /**
     * 通用线程池配置
     */
    @Bean("taskPoolExecutor")
    public Executor taskExecutor() {
        ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
        //设置线程池参数信息
        taskExecutor.setCorePoolSize(6);
        taskExecutor.setMaxPoolSize(6*2);
        taskExecutor.setQueueCapacity(12);
        taskExecutor.setKeepAliveSeconds(60);
        taskExecutor.setThreadNamePrefix("taskPoolExecutor--");
        taskExecutor.setWaitForTasksToCompleteOnShutdown(true);
        taskExecutor.setAwaitTerminationSeconds(60);
        //修改拒绝策略为使用当前线程执行
        taskExecutor.setRejectedExecutionHandler(new ThreadPoolExecutor.AbortPolicy());
        //初始化线程池
        taskExecutor.initialize();
        return taskExecutor;
    }

     /**
     * 发送短信线程池
     * @return
     */
    @Bean("sendSmsThreadPool")
    public Executor sendSmsThreadPool() {
        ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
        //设置线程池参数信息
        taskExecutor.setCorePoolSize(AVAILABLE_PROCESSOR);
        taskExecutor.setMaxPoolSize(AVAILABLE_PROCESSOR + 1);
        taskExecutor.setQueueCapacity(256);
        taskExecutor.setKeepAliveSeconds(20);
        taskExecutor.setThreadNamePrefix("sendSmsThreadPool--");
        taskExecutor.setWaitForTasksToCompleteOnShutdown(true);
        taskExecutor.setAwaitTerminationSeconds(60);
        //修改拒绝策略为使用当前线程执行
        taskExecutor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        //初始化线程池
        taskExecutor.initialize();
        return taskExecutor;
    }

    /**
     * 发送邮件线程池
     * @return
     */
    @Bean("sendEmailThreadPool")
    public Executor sendEmailThreadPool() {
        ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
        //设置线程池参数信息
        taskExecutor.setCorePoolSize(AVAILABLE_PROCESSOR);
        taskExecutor.setMaxPoolSize(AVAILABLE_PROCESSOR + 1);
        taskExecutor.setQueueCapacity(256);
        taskExecutor.setKeepAliveSeconds(20);
        taskExecutor.setThreadNamePrefix("sendEmailThreadPool--");
        taskExecutor.setWaitForTasksToCompleteOnShutdown(true);
        taskExecutor.setAwaitTerminationSeconds(60);
        //修改拒绝策略为使用当前线程执行
        taskExecutor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        //初始化线程池
        taskExecutor.initialize();
        return taskExecutor;
    }

    @Bean(name = "threadPoolTaskExecutor")
    public ThreadPoolTaskExecutor threadPoolTaskExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(5);
        executor.setMaxPoolSize(5);
        executor.setQueueCapacity(10);
        executor.setKeepAliveSeconds(300);
        executor.setThreadNamePrefix("thread-ayokredit"); //线程名称
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        return executor;
    }

    
}

2、使用@Async注解的问题

如果想要要结合Spring提供的异步注解@Async使用，需要在@Async注解中指定我们自定义的线程池的Bean。不指定我们自定义线程池的Bean的话将会默认使用Spring提供的线程池，默认情况下，每次都会创建一个新线程，如果在高并发的场景下，可能会产生大量的线程，从而导致OOM问题。
所以建议大家在@Async注解开启的异步功能时，请别忘了定义一个线程池，同时指明要生效的线程池的Bean。
如：