如何在Spring中有条件地启用或禁用计划作业？ [英] How to conditionally enable or disable scheduled jobs in Spring?

问题描述

我使用 @Scheduled 注释在Spring中使用cron样式的patten定义计划作业。

cron模式存储在配置属性文件中。实际上有两个属性文件：一个默认配置和一个与环境相关的配置文件配置（例如dev，test，prod客户1，prod客户2等），并覆盖某些默认值。

我在我的spring上下文中配置了一个属性占位符bean，它允许我使用 $ {} 样式占位符从属性文件中导入值。 / p>

作业bean类似如下：

  @Component 
 public class ImagesPurgeJob implements Job {
 
 private Logger logger = Logger.getLogger（this.getClass（））; 
 
 @Override 
 @Transactional（readOnly = true）
 @Scheduled（cron =$ {jobs.mediafiles.imagesPurgeJob.schedule}）
 public void execute （）{
 // Do something 
 //可以使用DAO或其他自动装配的bean 
} 
} 
  

我的上下文XML的相关部分：

 通过注释启用计划任务配置 - > 
< task：annotation-driven /> 
 
<！ - 加载配置文件并允许'$ {}'样式占位符 - > 
< bean class =org.springframework.context.support.PropertySourcesPlaceholderConfigurer> 
< property name =locations> 
< list> 
< value> classpath：config / default-config.properties< / value> 
< value> classpath：config / environment-config.properties< / value> 
< / list> 
< / property> 
< property name =ignoreUnresolvablePlaceholdersvalue =true/> 
< property name =ignoreResourceNotFoundvalue =false/> 
< / bean> 
  

我真的很喜欢这个。

但是，我还有一个要求：在某些情况下，其中一些工作可以完全禁用。

所以，在我使用Spring管理它们之前，我们手动创建它们，并且有一个布尔参数以及配置文件中的cron参数，用于指定是否必须启用该作业： / p>

  jobs.mediafiles.imagesPurgeJob.enable = true或false 
 jobs.mediafiles.imagesPurgeJob.schedule = 0 0 0 / 12 * *？ 
 

如何在Spring中使用此参数有条件地创建或只是简单地忽略bean config参数？

一个显而易见的解决方法是定义一个永远不会评估的cron模式，因此作业不会被执行。但是bean仍然会被创建，配置会有点模糊，所以我觉得必须有一个更好的解决方案。

任何想法？

解决方案

  @Component 
 public class ImagesPurgeJob implements Job {
 
私人记录器logger = Logger.getLogger（this.getClass（））; 
 
 @Value（$ {jobs.mediafiles.imagesPurgeJob.enable}）
 private boolean imagesPurgeJobEnable; 
 
 @Override 
 @Transactional（readOnly = true）
 @Scheduled（cron =$ {jobs.mediafiles.imagesPurgeJob.schedule}）
 public void execute （）{
 
 //做某事
 //可以使用DAO或其他自动装配的bean 
 if（imagesPurgeJobEnable）{
 
 here ... 
 
} 
} 
  

p>

I am defining scheduled jobs with cron style pattenrs in Spring, using the @Scheduled annotation.

The cron pattern is stored in a config properties file. Actually there are two properties files : one default config, and one profile config that is environment dependent (e.g. dev, test, prod customer 1, prod customer 2 etc.) and overrides some of the default values.

I configured a property placeholder bean in my spring context which allows me to use ${} style placeholders to import values from my properties files.

The job beans looks like this :

@Component
public class ImagesPurgeJob implements Job {

    private Logger logger = Logger.getLogger(this.getClass());

    @Override
    @Transactional(readOnly=true)
    @Scheduled(cron = "${jobs.mediafiles.imagesPurgeJob.schedule}")
    public void execute() {
        //Do something
            //can use DAO or other autowired beans here
    }
}

Relevant parts of my context XML :

<!-- Enable configuration of scheduled tasks via annotations -->
    <task:annotation-driven/>

<!-- Load configuration files and allow '${}' style placeholders -->
    <bean class="org.springframework.context.support.PropertySourcesPlaceholderConfigurer">
        <property name="locations">
            <list>
                <value>classpath:config/default-config.properties</value>
                <value>classpath:config/environment-config.properties</value>
            </list>
        </property>
        <property name="ignoreUnresolvablePlaceholders" value="true"/>
        <property name="ignoreResourceNotFound" value="false"/>
    </bean>

I really like this. It's quite simple and clean with minimal XML.

However I have one more requirement : some of these jobs can be totally disabled in some cases.

So, before I used Spring to manage them I created them manually and there is a boolean parameter along with the cron parameter in the config files, to specify if the job has to be enabled or not :

jobs.mediafiles.imagesPurgeJob.enable=true or false
jobs.mediafiles.imagesPurgeJob.schedule=0 0 0/12 * * ?

How can I use this parameter in Spring to conditionally create or just plainly ignore the bean, depending on this config parameter ?

One obvious workaround would be to define a cron pattern that would never evaluate, so the job is never executed. But the bean would still be created and the config would be a bit obscure, so I feel there must be a better solution.

Any idea ?

解决方案

@Component
public class ImagesPurgeJob implements Job {

    private Logger logger = Logger.getLogger(this.getClass());

    @Value("${jobs.mediafiles.imagesPurgeJob.enable}")
    private boolean imagesPurgeJobEnable;

    @Override
    @Transactional(readOnly=true)
    @Scheduled(cron = "${jobs.mediafiles.imagesPurgeJob.schedule}")
    public void execute() {

         //Do something
        //can use DAO or other autowired beans here
        if(imagesPurgeJobEnable){

            Do your conditional job here...

        }
   }

}

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