定时任务服务器不定时重启原因解析

现在定时任务服务存在问题，请帮忙核实一下:

现象：定时任务服务器的resin不定时重启，有时能达到一天一两次，原因是在创建单例bean时，单例bean正在被销毁。报错的类都是RunPickupPathService，每次重启前都会报如下错误。日志如下：

Caused by: org.springframework.beans.factory.BeanCreationNotAllowedException: Error creating bean with name 'transactionManager': Singleton bean creation not allowed while the singletons of this factory are in destruction (Do not request a bean from a BeanFactory in a destroy method implementation!)

[INFO]2014-08-15 15:46:27 INFO [resin-shutdown] org.springframework.scheduling.concurrent.ExecutorConfigurationSupport.shutdown(150) | Shutting down ExecutorService 'taskExecutor'

<!-- 定时检查捡货路径不完整的，　是否有补货进来，　如果补货了，则重新跑捡货路径 -->
    <bean id="xsaCheckUnCompletePathIsSupplied" class="org.springframework.scheduling.quartz.CronTriggerBean">
       <property name="jobDetail">
            <ref bean="xsaCheckUnCompletePathIsSuppliedJobDetail"/>
       </property>
       <property name="cronExpression">
            <value>${checkUnCompletePathIsSuppliedCron}</value>
       </property>
    </bean>
    <bean id="xsaCheckUnCompletePathIsSuppliedJobDetail" class="springframework.scheduling.quartz.BeanInvokingJobDetailFactoryBean">
        <property name="targetBean" value="runPickupPathService" />
        <property name="targetMethod" value="checkUnCompletePathIsSupplied" />
    </bean>

    <!-- 对于所有没有跑的捡货路径，进行跑捡货路径工作 -->
    <bean id="xsaRunUnRunPickupPath" class="org.springframework.scheduling.quartz.CronTriggerBean">
       <property name="jobDetail">
            <ref bean="xsaRunUnRunPickupPathJobDetail"/>
       </property>
       <property name="cronExpression">
            <value>${runUnRunPathCron}</value>
       </property>
    </bean>
    <bean id="xsaRunUnRunPickupPathJobDetail" class="springframework.scheduling.quartz.BeanInvokingJobDetailFactoryBean">
        <property name="targetBean" value="autoRunPickupPathService" />
        <property name="targetMethod" value="runAllUnRunPickupPath" />
    </bean>

这里targetBean autoRunPickupPathService 引用了如下的service，而 runPickupPathService 本身又是定时任务service，在跑完定时任务的时候需要被destory。

@Service
public class AutoRunPickupPathService {
    
    private final static Logger logger = LoggerFactory.getLogger(RunPickupPathService.class);
    @Resource
    private RunPickupPathService runPickupPathService;
    @Resource
    private XsaPickupPathMapper xsaPickupPathMapper;

    /**
     * 对于所有没有跑捡货路径的单据，跑捡货路径, 此方法设置为定时
     * @throws Exception 
     */
    public void runAllUnRunPickupPath() {
        synchronized (RunPickupPathService.class) {
            List<XsaPickupPath> pathList = xsaPickupPathMapper.getAllUnRunPickUpPath();
            if(null != pathList && pathList.size() > 0) {
                for(XsaPickupPath p : pathList) {
                    try {
                        runPickupPathService.runPickupPath(p.getServiceno(), true);
                    } catch (Exception e) {
                        logger.error("Auto Run Pickup Path Error, Transfer NO: " + p.getServiceno() + ", " + e.getMessage());
                    }
                }
            }
        }
    }

}

出现这种情况是下面情形，按时间先后出现如下 1->2->3->4

1、autoRunPickupPathService 已经运行结束，当前时间只有runPickupPathService 在运行。

2、runPickupPathService 运行完毕，发现此时没有别的类在引用自己，于是开始执行对bean的销毁（由spring控制，调用destory方法，不集成spring则由GC回收）。

3、在 runPickupPathService 正在销毁但销毁未完成的时候，定时任务 autoRunPickupPathService开始执行，由于类中引用了runPickupPathService ，于是开始创建runPickupPathService的实例。

4、由于spring的bean默认情况下都是单例（singleton），导致出现如上报错，即 Singleton bean creation not allowed while the singletons of this factory are in destruction 。

最终解释可以归为一句话:定时任务的相互调用会导致单例bean出现混乱。

解决方案：去掉定时任务之间的调用。

这是我分析的原因，我检测的三次重启都是由这个定时任务创建bean失败导致。