Quartz與Spring集成 Job如何自動注入Spring容器托管的對象

 

測試環境 Spring3 M2  quartz-2.1.7

 

我們要達到這樣的效果

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

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

但是Job對象的實例化過程是在Quartz中進行的，AppOrderService是在Spring容器當中的，那么如何將他們關聯到一起呢。好在Quartz提供了JobFactory接口，讓我們可以自定義實現創建Job的邏輯。

public interface JobFactory {

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

}

那么我們通過實現JobFactory 接口，在實例化Job以后，在通過ApplicationContext 將Job所需要的屬性注入即可

在Spring與Quartz集成時 用到的是org.springframework.scheduling.quartz.SchedulerFactoryBean這個類。源碼如下，我們只看最關鍵的地方。

        // 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);
            }
        }

其中紅色標記的是重點，如果我們不指定jobFactory，那么Spring就使用AdaptableJobFactory。我們在來看一下這個類的實現

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.");
        }
    }

}

其他的我們都不管，我們就看紅色的地方，這里是創建了一個Job,那我們就在這里去給Job的屬性進行注入就可以了，讓我們寫一個類繼承它，然后復寫這個方法進行對Job的注入。

public class MyJobFactory extends AdaptableJobFactory {

    //這個對象Spring會幫我們自動注入進來,也屬於Spring技術范疇.
    @Autowired
    private AutowireCapableBeanFactory capableBeanFactory;
    
    protected Object createJobInstance(TriggerFiredBundle bundle) throws Exception {
        //調用父類的方法
        Object jobInstance = super.createJobInstance(bundle);
        //進行注入,這屬於Spring的技術,不清楚的可以查看Spring的API.
        capableBeanFactory.autowireBean(jobInstance);
        return jobInstance;
    }
}

接下來把他配置到Spring當中去

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

然后在把org.springframework.scheduling.quartz.SchedulerFactoryBean的jobFactory設置成我們自己的。

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

這樣就完成了Spring對Job的注入功能，其實很簡單，原理就是在我們擴展JobFactory創建job的方法，在創建完Job以后進行屬性注入。