quartz整合spring框架service层对象注入为null解决方案

Job实现类代码

 package cn.itcast.quartz;

 import org.quartz.Job;
 import org.quartz.JobExecutionContext;
 import org.quartz.JobExecutionException;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;

 import cn.itcast.service.HelloServiceImpl;

 /**
  * @author: 攻城狮小白
  * @creationTime:2017年11月20日 下午5:21:28
  */
 @Service
 public class HelloJob implements Job{

     @Autowired
     private HelloServiceImpl helloServiceImpl;
     public void execute(JobExecutionContext context) throws JobExecutionException {
         helloServiceImpl.sayHello();
     }

 }

HelloJob.java

业务实现类代码

 package cn.itcast.service;

 import org.springframework.stereotype.Service;

 /**
  * @author: 攻城狮小白
  * @creationTime:2017年11月20日 下午5:42:12
  */
 @Service
 public class HelloServiceImpl {
     public void sayHello(){
         System.out.println("hello quartz...");
     }
 }

HelloServiceImpl.java

spring核心配置文件applicationContext.xml

 <?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:context="http://www.springframework.org/schema/context"
     xsi:schemaLocation="
         http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
         http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

     <context:component-scan base-package="cn.itcast"></context:component-scan>
     <bean id="jobDetail" class="org.springframework.scheduling.quartz.JobDetailFactoryBean">
         <property name="jobClass" value="cn.itcast.quartz.HelloJob"></property>
     </bean>

     <bean id="simpleTrigger" class="org.springframework.scheduling.quartz.SimpleTriggerFactoryBean">
         <property name="jobDetail" ref="jobDetail"></property>
         <property name="startDelay" value="3000"></property>
         <property name="repeatInterval" value="5000"></property>
     </bean>

     <bean id="scheduler" class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
         <property name="triggers">
             <list>
                 <ref bean="simpleTrigger"/>
             </list>
         </property>
     </bean>
 </beans>

applicationContext.xml

描述：按上面配置的代码执行时，helloServiceImpl对象会无法注入，会报空指针异常。

原因：因为JobDetailFactoryBean中注入的是一个cn.itcast.quartz.HelloJob实现类的全路径，底层会反射创建出一个HelloJob的对象，但是该对象不是由spring管理的，所以业务层的对象无法注入。

解决方案有如下两种

方案一：将如下类JobFactory复制放到自己项目下，然后修改配置文件，并将该JobFactory配置到applicationContext.xml中(详见配置文件第20行和第22行)，helloServiceImpl就能够被注入了。

 package cn.itcast.quartz;

 import org.quartz.spi.TriggerFiredBundle;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.config.AutowireCapableBeanFactory;
 import org.springframework.scheduling.quartz.AdaptableJobFactory;
 import org.springframework.stereotype.Service;

 @Service("jobFactory")
 public class JobFactory extends AdaptableJobFactory {
     @Autowired
     private AutowireCapableBeanFactory capableBeanFactory;
     @Override
     protected Object createJobInstance(TriggerFiredBundle bundle) throws Exception {
         // 调用父类的方法
         Object jobInstance = super.createJobInstance(bundle);
         // 进行注入
         capableBeanFactory.autowireBean(jobInstance);
         return jobInstance;
     }
 }

JobFactory.java

 <?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:context="http://www.springframework.org/schema/context"
     xsi:schemaLocation="
         http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
         http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

     <context:component-scan base-package="cn.itcast"></context:component-scan>
     <bean id="jobDetail" class="org.springframework.scheduling.quartz.JobDetailFactoryBean">
         <property name="jobClass" value="cn.itcast.quartz.HelloJob"></property>
     </bean>

     <bean id="simpleTrigger" class="org.springframework.scheduling.quartz.SimpleTriggerFactoryBean">
         <property name="jobDetail" ref="jobDetail"></property>
         <property name="startDelay" value="3000"></property>
         <property name="repeatInterval" value="5000"></property>
     </bean>

     <bean id="jobFactory" class="cn.itcast.quartz.JobFactory"></bean>
     <bean id="scheduler" class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
         <property name="jobFactory" ref="jobFactory"></property>
         <property name="triggers">
             <list>
                 <ref bean="simpleTrigger"/>
             </list>
         </property>
     </bean>
 </beans>

applicationContext.xml

方案二：在Job实现类中添加下面这行代码即可(这种方式虽然方便，但是当你的Job实现类过多时，需要给每个类都添加该行代码，所以当Job实现类过多的时候建议还是采用方案一，只需要配置一次就OK)

SpringBeanAutowiringSupport.processInjectionBasedOnCurrentContext(this);

 package cn.itcast.quartz;

 import org.quartz.Job;
 import org.quartz.JobExecutionContext;
 import org.quartz.JobExecutionException;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 import org.springframework.web.context.support.SpringBeanAutowiringSupport;

 import cn.itcast.service.HelloServiceImpl;

 /**
  * @author: 攻城狮小白
  * @creationTime:2017年11月20日 下午5:21:28
  */
 @Service
 public class HelloJob implements Job{
     @Autowired
     private HelloServiceImpl helloServiceImpl;
     public void execute(JobExecutionContext context) throws JobExecutionException {
         SpringBeanAutowiringSupport.processInjectionBasedOnCurrentContext(this);
         helloServiceImpl.sayHello();
     }
 }

HelloJob.java