Quartz与Spring的整合-Quartz中的job如何自动注入spring容器托管的对象

我们要达到这样的效果是在Quartz的Job实现类中引入spring 容器的服务，如下面源码参考：

public class CancelUnpaidOrderTask implements Job {
  @Autowired
  private AppOrderService orderService;

  @Override
  public void execute(JobExecutionContext ctx) throws JobExecutionException {
    ...
}

但是Job对象的实例化过程是在Quartz中进行的，AppOrderService是在Spring容器当中的，那么如何将他们关联到一起呢。 好在Quartz提供了JobFactory接口，让我们可以自定义实现创建Job的逻辑。

public interface JobFactory {

    Job newJob(TriggerFiredBundle bundle, Scheduler scheduler) throws SchedulerException;

}

那么我们通过实现JobFactory 接口，在实例化Job以后，在通过ApplicationContext 将Job所需要的属性注入即可
在Spring与Quartz集成时 用到的是org.springframework.scheduling.quartz.SchedulerFactoryBean这个类。源码如下，我们只看最关键的地方。

// Get Scheduler instance from SchedulerFactory.
    try {
      this.scheduler = createScheduler(schedulerFactory, this.schedulerName);
      populateSchedulerContext();

      if (!this.jobFactorySet && !(this.scheduler instanceof RemoteScheduler)) {
        // Use AdaptableJobFactory as default for a local Scheduler, unless when
        // explicitly given a null value through the "jobFactory" bean property.
        this.jobFactory = new AdaptableJobFactory();
      }
      if (this.jobFactory != null) {
        if (this.jobFactory instanceof SchedulerContextAware) {
          ((SchedulerContextAware) this.jobFactory).setSchedulerContext(this.scheduler.getContext());
        }
        this.scheduler.setJobFactory(this.jobFactory);
      }
    }

如果我们不指定jobFactory，那么Spring就使用AdaptableJobFactory。我们在来看一下这个类的实现
 

package org.springframework.scheduling.quartz;

import java.lang.reflect.Method;

import org.quartz.Job;
import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.spi.JobFactory;
import org.quartz.spi.TriggerFiredBundle;

import org.springframework.util.ReflectionUtils;


public class AdaptableJobFactory implements JobFactory {

   
  public Job newJob(TriggerFiredBundle bundle, Scheduler scheduler) throws SchedulerException {
    return newJob(bundle);
  }

  public Job newJob(TriggerFiredBundle bundle) throws SchedulerException {
    try {
      Object jobObject = createJobInstance(bundle);
      return adaptJob(jobObject);
    }
    catch (Exception ex) {
      throw new SchedulerException("Job instantiation failed", ex);
    }
  }

  protected Object createJobInstance(TriggerFiredBundle bundle) throws Exception {
    // Reflectively adapting to differences between Quartz 1.x and Quartz 2.0...
    Method getJobDetail = bundle.getClass().getMethod("getJobDetail");
    Object jobDetail = ReflectionUtils.invokeMethod(getJobDetail, bundle);
    Method getJobClass = jobDetail.getClass().getMethod("getJobClass");
    Class jobClass = (Class) ReflectionUtils.invokeMethod(getJobClass, jobDetail);
    return jobClass.newInstance();
  }

  protected Job adaptJob(Object jobObject) throws Exception {
    if (jobObject instanceof Job) {
      return (Job) jobObject;
    }
    else if (jobObject instanceof Runnable) {
      return new DelegatingJob((Runnable) jobObject);
    }
    else {
      throw new IllegalArgumentException("Unable to execute job class [" + jobObject.getClass().getName() +
          "]: only [org.quartz.Job] and [java.lang.Runnable] supported.");
    }
  }

}

其他的我们都不管，我们就看红色的地方，这里是创建了一个Job,那我们就在这里去给Job的属性进行注入就可以了，让我们写一个类继承它，然后复写这个方法进行对Job的注入。

public class MyJobFactory extends AdaptableJobFactory {

  //这个对象Spring会帮我们自动注入进来,也属于Spring技术范畴.
  @Autowired
  private AutowireCapableBeanFactory capableBeanFactory;
  
  protected Object createJobInstance(TriggerFiredBundle bundle) throws Exception {
    //调用父类的方法
    Object jobInstance = super.createJobInstance(bundle);
    //进行注入,这属于Spring的技术,不清楚的可以查看Spring的API.
    capableBeanFactory.autowireBean(jobInstance);
    return jobInstance;
  }
}

接下来把他配置到Spring当中去

<bean id="jobFactory" class="com.gary.operation.jobdemo.demo1.MyJobFactory"></bean>

然后在把org.springframework.scheduling.quartz.SchedulerFactoryBean的jobFactory设置成我们自己的。

<bean name="MyScheduler" class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
　　<!-- 其他属性省略 -->
　　<property name="jobFactory" ref="jobFactory"></property>
</bean>

这样就完成了Spring对Job的注入功能，其实很简单，原理就是在我们扩展JobFactory创建job的方法，在创建完Job以后进行属性注入。
 

Spring Quartz Java

https://blog.xqlee.com/article/15.html