我有一个监控应用程序，其中我正在运行fixedRate任务。这是拉入Consul配置的配置参数。我想引入更新的配置，所以我添加了@RefreshScope。但是只要我更新Consul上的配置值，fixedRate任务就会停止运行。
@Service
@RefreshScope
public class MonitorService {
@Autowired
private AppConfig appConfig;
@PostConstruct
public void postConstRun() {
System.out.println(appConfig.getMonitorConfig());
}
@Scheduled(fixedRate = 1000)
public void scheduledMonitorScan() {
System.out.println("MonitorConfig:" + appConfig.getMonitorConfig());
}
}
AppConfig类只有一个String参数：
@Configuration
@Getter
@Setter
public class AppConfig {
@Value("${monitor-config:default value}")
private String monitorConfig;
}
一旦我更新了consul中的值，计划任务就会停止运行（以sheduledMonitorScan方法显示）停止显示。
答案 0 :(得分：2)
import java.text.SimpleDateFormat;
import java.util.Date;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.cloud.context.scope.refresh.RefreshScopeRefreshedEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
@Component
@RefreshScope
public class AlertSchedulerCron implements ApplicationListener<RefreshScopeRefreshedEvent> {
private SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
@Value("${pollingtime}")
private String pollingtime;
/*
* @Value("${interval}") private String interval;
*/
@Scheduled(cron = "${pollingtime}")
//@Scheduled(fixedRateString = "${interval}" )
public void task() {
System.out.println(pollingtime);
System.out.println("Scheduler (cron expression) task with duration : " + sdf.format(new Date()));
}
@Override
public void onApplicationEvent(RefreshScopeRefreshedEvent event) {
// TODO Auto-generated method stub
}
}
答案 1 :(得分：1)
我已经通过实现SchedulingConfigurer接口完成了针对这种情况的解决方法。 在这里，我正在从外部属性文件动态更新“ scheduler.interval”属性，并且即使在执行器刷新后，调度程序也能正常工作，因为我不再使用@RefreshScope。 希望这对您有帮助。
public class MySchedulerImpl implements SchedulingConfigurer {
@Autowired
private Environment env;
@Bean(destroyMethod = "shutdown")
public Executor taskExecutor() {
return Executors.newScheduledThreadPool(10);
}
@Override
public void configureTasks(final ScheduledTaskRegistrar taskRegistrar) {
taskRegistrar.setScheduler(this.taskExecutor());
taskRegistrar.addTriggerTask(() -> {
//put your code here that to be scheduled
}, triggerContext -> {
final Calendar nextExecutionTime = new GregorianCalendar();
final Date lastActualExecutionTime = triggerContext.lastActualExecutionTime();
if (lastActualExecutionTime == null) {
nextExecutionTime.setTime(new Date());
} else {
nextExecutionTime.setTime(lastActualExecutionTime);
nextExecutionTime.add(Calendar.MILLISECOND, env.getProperty("scheduler.interval", Integer.class));
}
return nextExecutionTime.getTime();
});
}
}
答案 2 :(得分：1)
这是我们解决此问题的方法。
/**
* Listener of Spring's lifecycle to revive Scheduler beans, when spring's
* scope is refreshed.
* <p>
* Spring is able to restart beans, when we change their properties. Such a
* beans marked with RefreshScope annotation. To make it work, spring creates
* <b>lazy</b> proxies and push them instead of real object. The issue with
* scope refresh is that right after refresh in order for such a lazy proxy
* to be actually instantiated again someone has to call for any method of it.
* <p>
* It creates a tricky case with Schedulers, because there is no bean, which
* directly call anything on any Scheduler. Scheduler lifecycle is to start
* few threads upon instantiation and schedule tasks. No other bean needs
* anything from them.
* <p>
* To overcome this, we had to create artificial method on Schedulers and call
* them, when there is a scope refresh event. This actually instantiates.
*/
@RequiredArgsConstructor
public class RefreshScopeListener implements ApplicationListener<RefreshScopeRefreshedEvent> {
private final List<RefreshScheduler> refreshSchedulers;
@Override
public void onApplicationEvent(RefreshScopeRefreshedEvent event) {
refreshSchedulers.forEach(RefreshScheduler::materializeAfterRefresh);
}
}
因此，我们定义了一个接口，该接口不执行任何特殊操作，但允许我们调用刷新的作业。
public interface RefreshScheduler {
/**
* Used after refresh context for scheduler bean initialization
*/
default void materializeAfterRefresh() {
}
}
这是实际的作业，其参数from.properties可以刷新。
public class AJob implements RefreshScheduler {
@Scheduled(cron = "${from.properties}")
public void aTask() {
// do something useful
}
}
答案 3 :(得分：1)
我的解决方案包括听EnvironmentChangeEvent
@Configuration
public class SchedulingSpringConfig implements ApplicationListener<EnvironmentChangeEvent>, SchedulingConfigurer {
private static final Logger LOGGER = LoggerFactory.getLogger(SchedulingSpringConfig.class);
private final DemoProperties demoProperties;
public SchedulingSpringConfig(DemoProperties demoProperties) {
this.demoProperties = demoProperties;
}
@Override
public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
LOGGER.info("Configuring scheduled task with cron expression: {}", demoProperties.getCronExpression());
taskRegistrar.addTriggerTask(triggerTask());
taskRegistrar.setTaskScheduler(taskScheduler());
}
@Bean
public TriggerTask triggerTask() {
return new TriggerTask(this::work, cronTrigger());
}
private void work() {
LOGGER.info("Doing work!");
}
@Bean
@RefreshScope
public CronTrigger cronTrigger() {
return new CronTrigger(demoProperties.getCronExpression());
}
@Bean
public ThreadPoolTaskScheduler taskScheduler() {
return new ThreadPoolTaskScheduler();
}
@Override
public void onApplicationEvent(EnvironmentChangeEvent event) {
if (event.getKeys().contains("demo.config.cronExpression")) {
ScheduledTasksRefresher scheduledTasksRefresher = new ScheduledTasksRefresher(triggerTask());
scheduledTasksRefresher.afterPropertiesSet();
}
}
}
然后我使用ContextLifecycleScheduledTaskRegistrar重新创建任务。
public class ScheduledTasksRefresher extends ContextLifecycleScheduledTaskRegistrar {
private final TriggerTask triggerTask;
ScheduledTasksRefresher(TriggerTask triggerTask) {
this.triggerTask = triggerTask;
}
@Override
public void afterPropertiesSet() {
super.destroy();
super.addTriggerTask(triggerTask);
super.afterSingletonsInstantiated();
}
}
属性定义：
@ConfigurationProperties(prefix = "demo.config", ignoreUnknownFields = false)
public class DemoProperties {
private String cronExpression;
public String getCronExpression() {
return cronExpression;
}
public void setCronExpression(String cronExpression) {
this.cronExpression = cronExpression;
}
}
主要定义：
@SpringBootApplication
@EnableConfigurationProperties(DemoProperties.class)
@EnableScheduling
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}