定時任務實現方式:
定時任務執行方式:
package com.autonavi.task.test; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.scheduling.annotation.Scheduled; import org.springframework.stereotype.Component; import com.autonavi.task.ScheduledTasks; @Component public class ScheduledTest { private static final Logger logger = LoggerFactory.getLogger(ScheduledTasks.class); @Scheduled(cron="0 0/2 * * * ?") public void executeFileDownLoadTask() { // 間隔2分鐘,執行任務 Thread current = Thread.currentThread(); System.out.println("定時任務1:"+current.getId()); logger.info("ScheduledTest.executeFileDownLoadTask 定時任務1:"+current.getId()+ ",name:"+current.getName()); } }
@Scheduled 注解用於標注這個方法是一個定時任務的方法,有多種配置可選。cron支持cron表達式,指定任務在特定時間執行;fixedRate以特定頻率執行任務;fixedRateString以string的形式配置執行頻率。
@SpringBootApplication @EnableScheduling public class App { private static final Logger logger = LoggerFactory.getLogger(App.class); public static void main(String[] args) { SpringApplication.run(App.class, args); logger.info("start"); } }
其中 @EnableScheduling 注解的作用是發現注解@Scheduled的任務並後台執行。
Springboot本身默認的執行方式是串行執行,也就是說無論有多少task,都是一個線程串行執行,並行需手動配置
繼承SchedulingConfigurer類並重寫其方法即可,如下:
@Configuration @EnableScheduling public class ScheduleConfig implements SchedulingConfigurer { @Override public void configureTasks(ScheduledTaskRegistrar taskRegistrar) { taskRegistrar.setScheduler(taskExecutor()); } @Bean(destroyMethod="shutdown") public Executor taskExecutor() { return Executors.newScheduledThreadPool(100); } }
再次執行之前的那個Demo,會欣然發現已經是並行執行了!
import org.springframework.scheduling.TaskScheduler; import org.springframework.scheduling.annotation.AsyncConfigurer; import org.springframework.scheduling.annotation.EnableAsync; import org.springframework.scheduling.annotation.EnableScheduling; import org.springframework.scheduling.annotation.SchedulingConfigurer; import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler; import org.springframework.scheduling.config.ScheduledTaskRegistrar; @Configuration @EnableScheduling @EnableAsync( mode = AdviceMode.PROXY, proxyTargetClass = false, order = Ordered.HIGHEST_PRECEDENCE ) @ComponentScan( basePackages = "hello" ) public class RootContextConfiguration implements AsyncConfigurer, SchedulingConfigurer { @Bean public ThreadPoolTaskScheduler taskScheduler() { ThreadPoolTaskScheduler scheduler = new ThreadPoolTaskScheduler(); scheduler.setPoolSize(20); scheduler.setThreadNamePrefix("task-"); scheduler.setAwaitTerminationSeconds(60); scheduler.setWaitForTasksToCompleteOnShutdown(true); return scheduler; } @Override public Executor getAsyncExecutor() { Executor executor = this.taskScheduler(); return executor; } @Override public void configureTasks(ScheduledTaskRegistrar registrar) { TaskScheduler scheduler = this.taskScheduler(); registrar.setTaskScheduler(scheduler); } }
在啟動的main方法加入額外配置:
@SpringBootApplication public class Application { public static void main(String[] args) throws Exception { AnnotationConfigApplicationContext rootContext = new AnnotationConfigApplicationContext(); rootContext.register(RootContextConfiguration.class); rootContext.refresh(); } }