SpringBoot 多线程执行定时任务

最近做一个 SpringBoot 小项目时发现，项目正常启动后，一个定时任务正常执行，但是另一个定时任务却没开启，刚开始以为是哪里配置出了问题，经过一些排查发现两个定时任务线程名字是一样的，说明是同一个线程执行的，其中一个阻塞了，另一个自然不会执行。

SpringBoot 默认的定时任务

通过注解开启定时任务
@EnableScheduling

指定定时任务执行的周期或者 cron 表达式，作用在方法上
@Scheduled(cron = **"0 0 9,18 * * ? "**)

默认是单线程的~

多线程执行

通过注解 @EnableAsync 启用异步执行

增加线程池的配置

package com.gaoshan.ebpc.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import java.util.concurrent.Executor;
import java.util.concurrent.ThreadPoolExecutor;
/**
 * SpringBoot 定时任务 异步执行与线程池配置
 */
@EnableScheduling
@Configuration
@EnableAsync
public class ScheduleConfig {
    /**
     * 默认线程池配置
     *
     * @return {@link Executor}
     */
    @Bean(name = "defaultExecutor")
    public Executor executor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setThreadNamePrefix("ebpc-default-schedule-");
        executor.setMaxPoolSize(8);
        executor.setCorePoolSize(4);
        executor.setQueueCapacity(10);
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        return executor;
    }
    /**
     * 消费者线程池配置
     *
     * @return {@link Executor}
     */
    @Bean(name = "executor4Consumer")
    public Executor executor4Consumer() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setThreadNamePrefix("ebpc-consumer-schedule-");
        executor.setMaxPoolSize(8);
        executor.setCorePoolSize(4);
        executor.setQueueCapacity(20);
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        return executor;
    }
}

定时任务异步执行
@Async("defaultExecutor")

 /**
     * 2min 执行一次，查询最新的区块，并加入队列
     */
    @Async("defaultExecutor")
    @Scheduled(fixedRate = 120_000, initialDelay = 10_000)
    public void producer() {
        if (!ebpcEnable) {
            return;
        }
        if (pullBlockProcessor.getEthBlockQueue().isEmpty()) {
            log.info("+++++ 开始执行 NewBlockSyncTask +++++");
            pullBlockProcessor.sync(100);
            log.info("+++++ NewBlockSyncTask 执行结束 +++++");
        }
    }

@Async 注解的说明 Annotation that marks a method as a candidate for asynchronous execution. Can also be used at the type level, in which case all of the type’s methods are considered as asynchronous. Note, however, that @Async is not supported on methods declared within a @Configuration class.

将方法标记为异步执行候选方法的注解。 也可以在类型级别使用，在这种情况下，类型的所有方法都被视为异步的。 但是，请注意，@Configuration类中声明的方法不支持@Async。

动态定时任务

从数据库读取 cron 表达式，利用反射机制执行方法，类似 quartz ~

package com.gaoshan.ebpc.config;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.annotation.Bean;
import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler;
import org.springframework.stereotype.Component;
import java.time.Instant;
import java.util.concurrent.ScheduledFuture;
@Component
@Slf4j
public class DynamicTimedTask {
    //接受任务的返回结果
    private ScheduledFuture<?> future;
    private final ThreadPoolTaskScheduler threadPoolTaskScheduler;
    public DynamicTimedTask(ThreadPoolTaskScheduler threadPoolTaskScheduler) {
        this.threadPoolTaskScheduler = threadPoolTaskScheduler;
    }
    //实例化一个线程池任务调度类,可以使用自定义的ThreadPoolTaskScheduler
    @Bean
    public ThreadPoolTaskScheduler threadPoolTaskScheduler() {
        return new ThreadPoolTaskScheduler();
    }
    /**
     * 启动定时任务
     */
    public boolean startCron() {
        //从数据库动态获取执行周期
        String cron = "0/2 * * * * ? ";
        future = threadPoolTaskScheduler.schedule(new CheckModelFile(), Instant.parse(cron));
        return true;
    }
    /**
     * 停止定时任务
     *
     */
    public boolean stopCron() {
        boolean flag = false;
        if (future != null) {
            boolean cancel = future.cancel(true);
            if (cancel) {
                flag = true;
            }
        } else {
            flag = true;
        }
        return flag;
    }
    static class CheckModelFile implements Runnable {
        @Override
        public void run() {
            //编写你自己的业务逻辑
        }
    }
}