Quartz与Spring集成 Job如何自动注入Spring容器托管的对象

测试环境 Spring3 M2  quartz-2.1.7

 

我们要达到这样的效果

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);
            }
        }

其中红色标记的是重点，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。