用户可以在特定日期后通过 cron 表达式通过用户界面动态启动一些特定任务。任务存储在数据库中,以备需要重新启动时使用。
在研究一些替代方案时,我发现了 ScheduledTaskRegistrar 的解决方案。看起来不错。我的代码的主要部分如下。
我的问题是:如何停止上下文中任何最初/cron 启动的作业?
我查看了与 ScheduledTaskRegistrar 相关的类,但尚未找到任何解决方案。使用 Quartz 是另一种解决方案,但我更喜欢轻量级、简单的解决方案。
@Override
public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
this.taskRegistrar = taskRegistrar;
LocalDateTime now = LocalDateTime.now();
taskDefinitionRepository.findAll().forEach( t -> {
if( t.getFirstDateTime().isBefore( now)) {
taskRegistrar.addTriggerTask( exampleTaskBean, triggerContext -> {
if( triggerContext.lastScheduledExecutionTime() == null) {
return convertLocalDateTimeToDate( t.getFirstDateTime());
} else {
taskRegistrar.addCronTask( exampleTaskBean, t.getThenCronExpression());
return null;
}
});
} else {
taskRegistrar.addCronTask( exampleTaskBean, t.getThenCronExpression());
}
});
}
有办法停止特定任务吗?任务不会很多。
是否有更好的简单框架或者 Quartz 是正确的选择?
在调查现有的 Quartz 库时,(使用 iso 创建)该包不适合我的情况。它的数据库表比我的整个应用程序还要多。
在大约 15 分钟内,我编写了以下包。它对于使用 Cron 表达式调度任务来说已经足够好了。崩溃后,任务也会自动重新安排。
配置:
@Configuration
@EnableScheduling
public class TaskSchedulingConfig implements SchedulingConfigurer {
public static final int SCHEDULER_JOB_POOL_SIZE = 5;
@Override
public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
taskRegistrar.setTaskScheduler(taskScheduler());
}
@Bean
public TaskScheduler taskScheduler() {
ThreadPoolTaskScheduler scheduler = new ThreadPoolTaskScheduler();
scheduler.setPoolSize(SCHEDULER_JOB_POOL_SIZE);
scheduler.setThreadNamePrefix("SomeThreadScheduler__");
scheduler.initialize();
return scheduler;
}
}
任务定义:
@Builder
@NoArgsConstructor
@AllArgsConstructor
@Data
@Entity
@Table(name = "LTST_SCHEDULED_TASK")
public class TaskDefinition {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "LTST_ID", updatable = false, nullable = false)
private Long id;
@Column(name = "LTST_TASK_NAME")
private String taskName;
@Column(name = "LTST_CRON_EXPR")
private String cronExpression;
@Column(name = "LTST_TASK_DATA")
private String taskData;
}
样本服务。使用原型 bean 当然会更好,但就我而言,这已经足够好了。您可以轻松地增强这一点。
@Service
public class TaskDefinitionBean1 implements Runnable {
private final Logger logger = LoggerFactory.getLogger(TaskDefinitionBean1.class);
@Override
public void run() {
logger.info("Running job task-1");
}
}
调度服务,基于之前的配置:
@Service
public class TaskSchedulingService {
private static final Logger logger = LoggerFactory.getLogger(TaskSchedulingService.class);
private final TaskScheduler taskScheduler;
private final TaskDefinitionBean1 taskBean1;
private final TaskDefinitionBean2 taskBean2;
private final TaskDefinitionRepository taskDefinitionRepository;
private final Map<String, ScheduledFuture<?>> schedulerMap = new HashMap<>();
public TaskSchedulingService(TaskScheduler taskScheduler, TaskDefinitionBean1 taskBean1,
TaskDefinitionBean2 taskBean2, TaskDefinitionRepository taskDefinitionRepository) {
this.taskScheduler = taskScheduler;
this.taskBean1 = taskBean1;
this.taskBean2 = taskBean2;
this.taskDefinitionRepository = taskDefinitionRepository;
startScheduling();
}
private void startScheduling() {
taskDefinitionRepository.findAll().forEach(t -> {
logger.info("Start existing task '{}' with cron expression {}", t.getTaskName(), t.getCronExpression());
// Simplistic way to start different services ... good enough for prototyping
if( t.getTaskName().matches( "one")) {
schedulerMap.put(t.getTaskName(), taskScheduler.schedule(taskBean1, new CronTrigger(t.getCronExpression())));
} else {
schedulerMap.put(t.getTaskName(), taskScheduler.schedule(taskBean2, new CronTrigger(t.getCronExpression())));
}
});
}
public TaskDefinition addCronTask(String taskName, String cronExpression) {
if (schedulerMap.containsKey(taskName)) {
return null;
}
TaskDefinition taskDefinition = TaskDefinition.builder().taskName(taskName).cronExpression(cronExpression).build();
logger.info("Start new task '{}' with cron expression {}", taskDefinition.getTaskName(), taskDefinition.getCronExpression());
// Simplistic way to start different services ... good enough for prototyping
if( taskDefinition.getTaskName().matches( "one")) {
schedulerMap.put(taskDefinition.getTaskName(), taskScheduler.schedule(taskBean1, new CronTrigger(taskDefinition.getCronExpression())));
} else {
schedulerMap.put(taskDefinition.getTaskName(), taskScheduler.schedule(taskBean2, new CronTrigger(taskDefinition.getCronExpression())));
}
taskDefinitionRepository.save(taskDefinition);
return taskDefinition;
}
public void stopCronTask(String taskName) {
ScheduledFuture<?> scheduleJob = schedulerMap.get(taskName);
if (scheduleJob == null) {
return; // unknow job, so don't stop
}
scheduleJob.cancel(false);
taskDefinitionRepository.deleteByTaskName( taskName);
schedulerMap.remove(taskName);
}
public List<TaskDefinition> getScheduledTasks() {
return StreamSupport.stream(taskDefinitionRepository.findAll().spliterator(), false).toList();
}
}
将其放在 API 后面,以便您可以自己创建演示:
@RestController
@RequestMapping("/scheduledtasks")
public class ScheduleTaskController {
private static final Logger logger = LoggerFactory.getLogger(ScheduleTaskController.class);
private final TaskSchedulingService taskSchedulingService;
public ScheduleTaskController(TaskSchedulingService taskSchedulingService) {
this.taskSchedulingService = taskSchedulingService;
}
@GetMapping(value = "")
public ResponseEntity<List<TaskRequest>> getScheduleTasks() {
return ok().body( taskSchedulingService.getScheduledTasks().stream().map(this::convertTaskDefinitionToTaskRequest).toList());
}
@PostMapping(value = "", consumes = "application/json")
public ResponseEntity<TaskDefinition> startTaskWithName(@RequestBody TaskRequest taskRequest) {
logger.info("Start task with name {} and cronexpression {}", taskRequest.getTaskName(),
taskRequest.getCronExpression());
return status(HttpStatus.OK).body( taskSchedulingService.addCronTask( taskRequest.getTaskName(),
taskRequest.getCronExpression()));
}
@DeleteMapping(value = "/{taskname}")
public ResponseEntity<TaskRequest> deleteTaskWithName(@PathVariable("taskname") String taskname) {
logger.info("Delete task with name {}", taskname);
taskSchedulingService.stopCronTask( taskname);
return status(HttpStatus.OK).body( new TaskRequest( taskname, ""));
}
private TaskRequest convertTaskDefinitionToTaskRequest( TaskDefinition taskDefinition) {
return new TaskRequest(taskDefinition.getTaskName(), taskDefinition.getCronExpression());
}
}
最后,一种用于任务的 POJO:
@AllArgsConstructor
@Data
public class TaskRequest {
private String taskName;
private String cronExpression;
}