在Java中,使用Quartz框架可以實(shí)現(xiàn)任務(wù)調(diào)度和依賴執(zhí)行。Quartz是一個(gè)功能強(qiáng)大的開(kāi)源作業(yè)調(diào)度庫(kù),可以用于執(zhí)行定時(shí)任務(wù)或者作業(yè)。要實(shí)現(xiàn)任務(wù)的依賴執(zhí)行,你需要?jiǎng)?chuàng)建一個(gè)JobListener,并在其中實(shí)現(xiàn)任務(wù)之間的依賴關(guān)系。
以下是一個(gè)簡(jiǎn)單的示例,展示了如何使用Quartz實(shí)現(xiàn)任務(wù)的依賴執(zhí)行:
<groupId>org.quartz-scheduler</groupId>
<artifactId>quartz</artifactId>
<version>2.3.2</version>
</dependency>
public class JobA implements Job {
@Override
public void execute(JobExecutionContext context) throws JobExecutionException {
System.out.println("Job A is executing...");
}
}
public class JobB implements Job {
@Override
public void execute(JobExecutionContext context) throws JobExecutionException {
System.out.println("Job B is executing...");
}
}
public class DependencyJobListener extends JobListenerSupport {
@Override
public String getName() {
return "DependencyJobListener";
}
@Override
public void jobWasExecuted(JobExecutionContext context, JobExecutionException jobException) {
String jobName = context.getJobDetail().getKey().getName();
if ("JobA".equals(jobName)) {
try {
// 當(dāng)JobA執(zhí)行完成后,觸發(fā)JobB的執(zhí)行
JobKey jobBKey = new JobKey("JobB", "group1");
JobDetail jobB = context.getScheduler().getJobDetail(jobBKey);
if (jobB != null) {
context.getScheduler().triggerJob(jobBKey);
}
} catch (SchedulerException e) {
e.printStackTrace();
}
}
}
}
public class QuartzDemo {
public static void main(String[] args) {
try {
// 創(chuàng)建調(diào)度器
SchedulerFactory schedulerFactory = new StdSchedulerFactory();
Scheduler scheduler = schedulerFactory.getScheduler();
// 創(chuàng)建JobDetail
JobDetail jobA = JobBuilder.newJob(JobA.class)
.withIdentity("JobA", "group1")
.build();
JobDetail jobB = JobBuilder.newJob(JobB.class)
.withIdentity("JobB", "group1")
.build();
// 創(chuàng)建Trigger
Trigger triggerA = TriggerBuilder.newTrigger()
.withIdentity("TriggerA", "group1")
.startNow()
.withSchedule(SimpleScheduleBuilder.simpleSchedule()
.withIntervalInSeconds(5)
.repeatForever())
.build();
// 將JobDetail和Trigger添加到調(diào)度器中
scheduler.scheduleJob(jobA, triggerA);
scheduler.addJob(jobB, true);
// 將JobListener添加到調(diào)度器中
scheduler.getListenerManager().addJobListener(new DependencyJobListener());
// 啟動(dòng)調(diào)度器
scheduler.start();
} catch (SchedulerException e) {
e.printStackTrace();
}
}
}
在這個(gè)示例中,我們創(chuàng)建了兩個(gè)Job(JobA和JobB),并在JobListener中實(shí)現(xiàn)了任務(wù)依賴關(guān)系。當(dāng)JobA執(zhí)行完成后,JobB會(huì)被觸發(fā)執(zhí)行。你可以根據(jù)自己的需求修改JobListener中的邏輯,以實(shí)現(xiàn)不同的任務(wù)依賴關(guān)系。