Spring使用之：Quartz定时任务为什么会被阻塞

周日，公司CTO给我打电话说，监控系统的数据从下午1点就不更新了。我登录服务器排除了数据同步问题，查看日志也没有例外抛出，查询了前一天的 日志发现几个数据库表空间溢出例外。最后定位，Spring定时任务挂掉了。重启应用恢复正常。周一早上，同样的问题又发生了，6点开始定时任务又停了。 Spring定时任务为什么会被阻塞呢？ 

原因： 

周一中午，我在进行接口状态监控测试时发现，接口状态查询任务尽然会执行半小时。问题找到了，由于我在接口状态查询任务中没有设置读超时、在接口 网络繁忙时，接口状态查询任务会占用很长的时间，Spring定时任务默认都是并发执行的，不会等待上一次任务执行完毕，只要间隔时间到就会执行。接口状 态查询任务每5分钟执行一次，假如每次都执行1小时的话，其他任务就会被阻塞。因为Quartz的线程都被接口状态查询任务占用了。其他任务只有等待。 

解决方法： 

1.将JobDetail的concurrent属性配置为false。不允许任务并发执行。 
2.任务执行时间较长时，查找根本问题。 

实验： 

JobOne.java

 package  test.job;

 import  java.util.Date;

 public   class  JobOne {
     public   void  execute(){
         System.out.println("execute JobOne(" + new  Date()+ ")" );
         try  {
             Thread.sleep(1000000 );
         }catch (InterruptedException ire) {

         }
     }
 }

 package test.job;

 import java.util.Date;

 public class JobOne {
     public void execute(){
         System.out.println("execute JobOne("+new Date()+")");
         try {
             Thread.sleep(1000000);
         }catch(InterruptedException ire) {

         }
     }
 }

JobTwo.java

 package  test.job;

 import  java.util.Date;

 public   class  JobTwo {
     public   void  execute(){
         System.out.println("execute JobTwo(" + new  Date()+ ")" );
     }

 }

 package test.job;

 import java.util.Date;

 public class JobTwo {
     public void execute(){
         System.out.println("execute JobTwo("+new Date()+")");
     }

 }

配置文件

  xml   version = "1.0"   encoding = "UTF-8" ?>
 < beans   xmlns = "http://www.springframework.org/schema/beans"   xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:aop = "http://www.springframework.org/schema/aop"   xmlns:tx ="http://www.springframework.org/schema/tx"
        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-

 beans-2.0.xsd
             http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
             http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd">





     < bean   id = "jobOne"   class = "test.job.JobOne"   >

      bean >



     < bean   id = "jobOneDetail"   class ="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean" >
         < property   name = "targetObject"   ref = "jobOne" />
         < property   name = "targetMethod"   value = "execute" />
         < property   name = "concurrent"   value = "true"   />
      bean >



     < bean   id = "jobOneSimpleTrigger"   class ="org.springframework.scheduling.quartz.SimpleTriggerBean" >
         < property   name = "jobDetail"   ref = "jobOneDetail"   />
         < property   name = "startDelay" > < value > 0  value >  property >
         < property   name = "repeatInterval" > < value > 1000  value >  property >
      bean >





     < bean   id = "jobTwo"   class = "test.job.JobTwo"   >

      bean >



     < bean   id = "jobTwoDetail"   class ="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean" >
         < property   name = "targetObject"   ref = "jobTwo" />
         < property   name = "targetMethod"   value = "execute" />
         < property   name = "concurrent"   value = "true"   />
      bean >



     < bean   id = "jobTwoSimpleTrigger"   class ="org.springframework.scheduling.quartz.SimpleTriggerBean" >
         < property   name = "jobDetail"   ref = "jobTwoDetail"   />
         < property   name = "startDelay" > < value > 0  value >  property >
         < property   name = "repeatInterval" > < value > 1000  value >  property >
      bean >






     < bean    class = "org.springframework.scheduling.quartz.SchedulerFactoryBean" >
         < property   name = "triggers" >
             < list >
                 < ref   local = "jobOneSimpleTrigger" />
                 < ref   local = "jobTwoSimpleTrigger" />
              list >
          property >
      bean >

  beans >

 xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-

 beans-2.0.xsd
             http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
             http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd">





     <bean id="jobOne" class="test.job.JobOne" >

     bean>



     <bean id="jobOneDetail" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">
         <property name="targetObject" ref="jobOne"/>
         <property name="targetMethod" value="execute"/>
         <property name="concurrent" value="true" />
     bean>



     <bean id="jobOneSimpleTrigger" class="org.springframework.scheduling.quartz.SimpleTriggerBean">
         <property name="jobDetail" ref="jobOneDetail" />
         <property name="startDelay"><value>0value>property>
         <property name="repeatInterval"><value>1000value>property>
     bean>





     <bean id="jobTwo" class="test.job.JobTwo" >

     bean>



     <bean id="jobTwoDetail" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">
         <property name="targetObject" ref="jobTwo"/>
         <property name="targetMethod" value="execute"/>
         <property name="concurrent" value="true" />
     bean>



     <bean id="jobTwoSimpleTrigger" class="org.springframework.scheduling.quartz.SimpleTriggerBean">
         <property name="jobDetail" ref="jobTwoDetail" />
         <property name="startDelay"><value>0value>property>
         <property name="repeatInterval"><value>1000value>property>
     bean>






     <bean  class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
         <property name="triggers">
             <list>
                 <ref local="jobOneSimpleTrigger"/>
                 <ref local="jobTwoSimpleTrigger"/>
             list>
         property>
     bean>

 beans>

MAIN类：

 package  test.job;

 import  org.springframework.context.ApplicationContext;
 import  org.springframework.context.support.ClassPathXmlApplicationContext;

 public   class  JobTest {
     private   ApplicationContext ac;

     public  JobTest(ApplicationContext ac) {
         this .ac = ac;
     }
     /**
      * @param args
      */
     public   static   void  main(String[] args) {
         JobTest job = new  JobTest( new  ClassPathXmlApplicationContext("applicationContext.xml" ));


     }

 }

 package test.job;

 import org.springframework.context.ApplicationContext;
 import org.springframework.context.support.ClassPathXmlApplicationContext;

 public class JobTest {
     private  ApplicationContext ac;

     public JobTest(ApplicationContext ac) {
         this.ac = ac;
     }
     /**
      * @param args
      */
     public static void main(String[] args) {
         JobTest job = new JobTest(new ClassPathXmlApplicationContext("applicationContext.xml"));


     }

 }

测试结果： 

当jobOne的concurrent为true时： 

execute JobOne(Thu Jan 24 13:40:22 CST 2008) 
execute JobTwo(Thu Jan 24 13:40:22 CST 2008) 
execute JobOne(Thu Jan 24 13:40:22 CST 2008) 
execute JobTwo(Thu Jan 24 13:40:22 CST 2008) 
execute JobOne(Thu Jan 24 13:40:23 CST 2008) 
execute JobTwo(Thu Jan 24 13:40:23 CST 2008) 
execute JobOne(Thu Jan 24 13:40:24 CST 2008) 
execute JobTwo(Thu Jan 24 13:40:24 CST 2008) 
execute JobOne(Thu Jan 24 13:40:25 CST 2008) 
execute JobTwo(Thu Jan 24 13:40:25 CST 2008) 
execute JobOne(Thu Jan 24 13:40:26 CST 2008) 
execute JobTwo(Thu Jan 24 13:40:26 CST 2008) 
execute JobOne(Thu Jan 24 13:40:27 CST 2008) 
execute JobTwo(Thu Jan 24 13:40:27 CST 2008) 
execute JobOne(Thu Jan 24 13:40:28 CST 2008) 
execute JobTwo(Thu Jan 24 13:40:28 CST 2008) 
execute JobOne(Thu Jan 24 13:40:29 CST 2008) 
execute JobTwo(Thu Jan 24 13:40:29 CST 2008) 
execute JobOne(Thu Jan 24 13:40:31 CST 2008) 

（JobOne并发执行，到这里所有任务阻塞没有信息输出，可以看出默认有10个线程，都被JobOne占用） 

当jobOne的concurrent为false时： 

execute JobOne(Thu Jan 24 13:43:00 CST 2008) 
execute JobTwo(Thu Jan 24 13:43:00 CST 2008) 
execute JobTwo(Thu Jan 24 13:43:00 CST 2008) 
execute JobTwo(Thu Jan 24 13:43:01 CST 2008) 
execute JobTwo(Thu Jan 24 13:43:02 CST 2008) 
execute JobTwo(Thu Jan 24 13:43:03 CST 2008) 
execute JobTwo(Thu Jan 24 13:43:04 CST 2008) 
execute JobTwo(Thu Jan 24 13:43:05 CST 2008) 
execute JobTwo(Thu Jan 24 13:43:06 CST 2008) 
execute JobTwo(Thu Jan 24 13:43:07 CST 2008) 
execute JobTwo(Thu Jan 24 13:43:08 CST 2008) 
execute JobTwo(Thu Jan 24 13:43:09 CST 2008) 

（JobOne不并发执行，JobTwo不会被阻塞）