1、XxlJobAdminConfig初始化

     1）使用静态方法getAdminConfig生成XxlJobAdminConfig生成单例对象，通过InitializingBean和DisposableBean完成静态对象赋值、初始化、和Spring Boot任务结束后对象线程池关闭,XxlJobAdminConfig对象注入到IOC容器后创建XxlJobScheduler对象并调用init方法，完成一系列线程池的初始化操作

@Component
public class XxlJobAdminConfig implements InitializingBean, DisposableBean {

    private static XxlJobAdminConfig adminConfig = null;
    public static XxlJobAdminConfig getAdminConfig() {
        return adminConfig;
    }

    // ---------------------- XxlJobScheduler ----------------------

    private XxlJobScheduler xxlJobScheduler;

    @Override
    public void afterPropertiesSet() throws Exception {
        adminConfig = this;

        xxlJobScheduler = new XxlJobScheduler();
        xxlJobScheduler.init();
    }

    @Override
    public void destroy() throws Exception {
        xxlJobScheduler.destroy();
    }

}

2）XxlJobScheduler的初始化方法init和线程池一系列的销毁方法

public class XxlJobScheduler  {
    private static final Logger logger = LoggerFactory.getLogger(XxlJobScheduler.class);


    public void init() throws Exception {
        // init i18n
        initI18n();

        // admin trigger pool start
        JobTriggerPoolHelper.toStart();

        // admin registry monitor run
        JobRegistryHelper.getInstance().start();

        // admin fail-monitor run
        JobFailMonitorHelper.getInstance().start();

        // admin lose-monitor run ( depend on JobTriggerPoolHelper )
        JobCompleteHelper.getInstance().start();

        // admin log report start
        JobLogReportHelper.getInstance().start();

        // start-schedule  ( depend on JobTriggerPoolHelper )
        JobScheduleHelper.getInstance().start();

        logger.info(">>>>>>>>> init xxl-job admin success.");
    }

    
    public void destroy() throws Exception {

        // stop-schedule
        JobScheduleHelper.getInstance().toStop();

        // admin log report stop
        JobLogReportHelper.getInstance().toStop();

        // admin lose-monitor stop
        JobCompleteHelper.getInstance().toStop();

        // admin fail-monitor stop
        JobFailMonitorHelper.getInstance().toStop();

        // admin registry stop
        JobRegistryHelper.getInstance().toStop();

        // admin trigger pool stop
        JobTriggerPoolHelper.toStop();

    }

}

3）JobTriggerPoolHelper类start方法创建两个线程池fastTriggerPool和slowTriggerPool，通过配置来设置最大线程数