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This article mainly explains "what support Spring provides for Quartz task scheduling". The explanation in this article is simple and clear, easy to learn and understand. Please follow the ideas of Xiaobian and go deep into it slowly to study and learn "what support Spring provides for Quartz task scheduling" together.

The Spring Framework provides rich Quartz task scheduling support, such as when to perform what tasks, it is an open source project maintained by OpenSymphony, developers can use it in Java EE, or stand-alone Java SE applications. Quartz is well suited for simple task scheduling and complex enterprise applications. These tasks can be ordinary POJOs or even EJB 3.0 components.

Quartz is ideal for developers who want to develop applications that:

Drive workflow: For example, if a newly created process task needs to be processed in 2 hours, Quartz checks whether the order was successfully processed after 2 hours. If not, Quartz processes the order according to the rules defined by the workflow, destroys it, or performs other processing.

System maintenance work: For example, exporting the contents of an RDBMS to XML files at fixed times each weekday.

Spring 2.0 provides the org.springframework.scheduling.quartz package to support Quartz task scheduling integration. To provide user tasks, developer implemented classes must inherit from the quartz.QuartzJobBean abstract class. QuartzJobBean is a simple implementation (subclass) of the org.quartz.Job interface in Quartz, and Spring provides QuartzJobBean classes to simplify the implementation of the Job interface. QuartzJobBean is similar to TimerTask in Java 2 SDK and is used to define the task itself. The executeInternal() method defines the task to be executed, similar to run() in TimerTask. The definition of ListImagesQuartzJob in imagedb is given below, which is almost indistinguishable from ListImagesTimerTask.

public class ListImagesQuartzJob extends QuartzJobBean {

private ImageDatabase imageDatabase;

private MailSender mailSender;

private String mailFrom;

private String mailTo;

public void setImageDatabase(ImageDatabase imageDatabase) {

this.imageDatabase = imageDatabase;

}

public void setMailSender(MailSender mailSender) {

this.mailSender = mailSender;

}

public void setMailFrom(String mailFrom) {

this.mailFrom = mailFrom;

}

public void setMailTo(String mailTo) {

this.mailTo = mailTo;

}

protected void executeInternal(JobExecutionContext context) {

......

logger.info("Next job execution at: " + context.getNextFireTime());

}

}

Developers can specify user tasks to be completed through the executeInternal() method, and pass context to it to obtain contextual information about the task execution, such as the next time the user task will be executed. Next, we specify the scheduling rules, which are configured in context/WEB-INF/schedulingContext-quartz.xml. JobDetailBean is a subclass of org.quartz.JobDetail in Quartz, and Spring provides JobDetailBean to simplify the development of the JobDetail subclass. The jobClass attribute in the JobDetailBean enables you to set the Job object type, while the jobDataAsMap attribute enables you to provide target values for various attributes of ListImagesQuartzJob.

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SimpleTriggerBean is a subclass of org.quartz.SimpleTrigger in Quartz, and Spring provides it to simplify the development of SimpleTrigger subclasses. To specify scheduling rules, developers need to use them to set how often and when tasks run. SimpleTriggerBean is similar to Scheduled TimerTask in Timer Task Scheduling, but more powerful. In this case, the startDelay property exposed by SimpleTriggerBean has the same meaning as the delay property in ScheduledTimerTask, and the repeatInterval property has the same meaning as the period property.

To specify more complex task scheduling rules, developers use Spring's CronTriggerBean, which is a subclass of org.quartz.CronTrigger in Quartz. Spring 2.0 provides CronTriggerBean to simplify the development of CronTrigger subclasses. CronTriggerBean is more powerful than SimpleTriggerBean in that it can control the exact time at which tasks are executed, for example, a task given in a QuartzJobBean needs to be executed at 9:30 a.m. The cronExpression attribute in the CronTriggerBean enables you to set the execution timing of tasks. An example configuration is shown below.

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The configuration snippet above also uses a MethodInvokingJobDetailFactoryBean, which can specify plain POJOs as user tasks. This is another strategy for specifying user tasks supported by the Spring Quartz Task Scheduling Integration.

After formulating the above two scheduling rules, developers need to implement them, and Scheduler FactoryBean can take care of this task. The example configuration is as follows. The triggers attribute enables developers to specify a collection of SimpleTriggerBeans and CronTriggerBeans, and the quartzProperties attribute enables developers to control Quartz details, such as the number of threads in the thread pool.

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props>

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Thank you for reading, the above is "Spring Quartz task scheduling provides what support" content, after learning this article, I believe we have a deeper understanding of Spring Quartz task scheduling provides what support this problem, the specific use of the situation also needs to be verified by practice. Here is, Xiaobian will push more articles related to knowledge points for everyone, welcome to pay attention!

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