该内容已被发布者删除 该内容被自由微信恢复
文章于 2021年12月22日 被检测为删除。
查看原文
被用户删除
其他

Spring Boot 实现定时任务的动态增删启停!

点击关注 👉 鸭哥聊Java 2021-12-16

大家好,我是鸭哥。


答案


在spring boot项目中,可以通过@EnableScheduling注解和@Scheduled注解实现定时任务,也可以通过SchedulingConfigurer接口来实现定时任务。但是这两种方式不能动态添加、删除、启动、停止任务。


要实现动态增删启停定时任务功能,比较广泛的做法是集成Quartz框架。但是本人的开发原则是:在满足项目需求的情况下,尽量少的依赖其它框架,避免项目过于臃肿和复杂。


查看spring-context这个jar包中

org.springframework.scheduling.ScheduledTaskRegistrar这个类的源代码,发现可以通过改造这个类就能实现动态增删启停定时任务功能。


定时任务列表页


定时任务执行日志


添加执行定时任务的线程池配置类

@Configurationpublic class SchedulingConfig { @Bean public TaskScheduler taskScheduler() { ThreadPoolTaskScheduler taskScheduler = new ThreadPoolTaskScheduler(); // 定时任务执行线程池核心线程数 taskScheduler.setPoolSize(4); taskScheduler.setRemoveOnCancelPolicy(true); taskScheduler.setThreadNamePrefix("TaskSchedulerThreadPool-"); return taskScheduler; }}

添加ScheduledFuture的包装类。ScheduledFuture是ScheduledExecutorService定时任务线程池的执行结果。

public final class ScheduledTask {
volatile ScheduledFuture<?> future;
/** * 取消定时任务 */ public void cancel() { ScheduledFuture<?> future = this.future; if (future != null) { future.cancel(true); } }}

添加Runnable接口实现类,被定时任务线程池调用,用来执行指定bean里面的方法。

public class SchedulingRunnable implements Runnable {
private static final Logger logger = LoggerFactory.getLogger(SchedulingRunnable.class);
private String beanName;
private String methodName;
private String params;
public SchedulingRunnable(String beanName, String methodName) { this(beanName, methodName, null); }
public SchedulingRunnable(String beanName, String methodName, String params) { this.beanName = beanName; this.methodName = methodName; this.params = params; }
@Override public void run() { logger.info("定时任务开始执行 - bean:{},方法:{},参数:{}", beanName, methodName, params); long startTime = System.currentTimeMillis();
try { Object target = SpringContextUtils.getBean(beanName);
Method method = null; if (StringUtils.isNotEmpty(params)) { method = target.getClass().getDeclaredMethod(methodName, String.class); } else { method = target.getClass().getDeclaredMethod(methodName); }
ReflectionUtils.makeAccessible(method); if (StringUtils.isNotEmpty(params)) { method.invoke(target, params); } else { method.invoke(target); } } catch (Exception ex) { logger.error(String.format("定时任务执行异常 - bean:%s,方法:%s,参数:%s ", beanName, methodName, params), ex); }
long times = System.currentTimeMillis() - startTime; logger.info("定时任务执行结束 - bean:{},方法:{},参数:{},耗时:{} 毫秒", beanName, methodName, params, times); }
@Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; SchedulingRunnable that = (SchedulingRunnable) o; if (params == null) { return beanName.equals(that.beanName) && methodName.equals(that.methodName) && that.params == null; }
return beanName.equals(that.beanName) && methodName.equals(that.methodName) && params.equals(that.params); }
@Override public int hashCode() { if (params == null) { return Objects.hash(beanName, methodName); }
return Objects.hash(beanName, methodName, params); }}

添加定时任务注册类,用来增加、删除定时任务。

@Componentpublic class CronTaskRegistrar implements DisposableBean {
private final Map<Runnable, ScheduledTask> scheduledTasks = new ConcurrentHashMap<>(16);
@Autowired private TaskScheduler taskScheduler;
public TaskScheduler getScheduler() { return this.taskScheduler; }
public void addCronTask(Runnable task, String cronExpression) { addCronTask(new CronTask(task, cronExpression)); }
public void addCronTask(CronTask cronTask) { if (cronTask != null) { Runnable task = cronTask.getRunnable(); if (this.scheduledTasks.containsKey(task)) { removeCronTask(task); }
this.scheduledTasks.put(task, scheduleCronTask(cronTask)); } }
public void removeCronTask(Runnable task) { ScheduledTask scheduledTask = this.scheduledTasks.remove(task); if (scheduledTask != null) scheduledTask.cancel(); }
public ScheduledTask scheduleCronTask(CronTask cronTask) { ScheduledTask scheduledTask = new ScheduledTask(); scheduledTask.future = this.taskScheduler.schedule(cronTask.getRunnable(), cronTask.getTrigger());
return scheduledTask; }

@Override public void destroy() { for (ScheduledTask task : this.scheduledTasks.values()) { task.cancel(); }
this.scheduledTasks.clear(); }}


添加定时任务示例类

@Component("demoTask")public class DemoTask { public void taskWithParams(String params) { System.out.println("执行有参示例任务:" + params); }
public void taskNoParams() { System.out.println("执行无参示例任务"); }}


定时任务数据库表设计


定时任务数据库表设计


添加定时任务实体类

public class SysJobPO { /** * 任务ID */ private Integer jobId; /** * bean名称 */ private String beanName; /** * 方法名称 */ private String methodName; /** * 方法参数 */ private String methodParams; /** * cron表达式 */ private String cronExpression; /** * 状态(1正常 0暂停) */ private Integer jobStatus; /** * 备注 */ private String remark; /** * 创建时间 */ private Date createTime; /** * 更新时间 */ private Date updateTime;
public Integer getJobId() { return jobId; }
public void setJobId(Integer jobId) { this.jobId = jobId; }
public String getBeanName() { return beanName; }
public void setBeanName(String beanName) { this.beanName = beanName; }
public String getMethodName() { return methodName; }
public void setMethodName(String methodName) { this.methodName = methodName; }
public String getMethodParams() { return methodParams; }
public void setMethodParams(String methodParams) { this.methodParams = methodParams; }
public String getCronExpression() { return cronExpression; }
public void setCronExpression(String cronExpression) { this.cronExpression = cronExpression; }
public Integer getJobStatus() { return jobStatus; }
public void setJobStatus(Integer jobStatus) { this.jobStatus = jobStatus; }
public String getRemark() { return remark; }
public void setRemark(String remark) { this.remark = remark; }
public Date getCreateTime() { return createTime; }
public void setCreateTime(Date createTime) { this.createTime = createTime; }
public Date getUpdateTime() { return updateTime; }
public void setUpdateTime(Date updateTime) { this.updateTime = updateTime; }
}

新增定时任务

新增定时任务

boolean success = sysJobRepository.addSysJob(sysJob);if (!success) return OperationResUtils.fail("新增失败");else { if (sysJob.getJobStatus().equals(SysJobStatus.NORMAL.ordinal())) { SchedulingRunnable task = new SchedulingRunnable(sysJob.getBeanName(), sysJob.getMethodName(), sysJob.getMethodParams()); cronTaskRegistrar.addCronTask(task, sysJob.getCronExpression()); }}
return OperationResUtils.success();

修改定时任务,先移除原来的任务,再启动新任务

boolean success = sysJobRepository.editSysJob(sysJob);if (!success) return OperationResUtils.fail("编辑失败");else { //先移除再添加 if (existedSysJob.getJobStatus().equals(SysJobStatus.NORMAL.ordinal())) { SchedulingRunnable task = new SchedulingRunnable(existedSysJob.getBeanName(), existedSysJob.getMethodName(), existedSysJob.getMethodParams()); cronTaskRegistrar.removeCronTask(task); }
if (sysJob.getJobStatus().equals(SysJobStatus.NORMAL.ordinal())) { SchedulingRunnable task = new SchedulingRunnable(sysJob.getBeanName(), sysJob.getMethodName(), sysJob.getMethodParams()); cronTaskRegistrar.addCronTask(task, sysJob.getCronExpression()); }}
return OperationResUtils.success();

删除定时任务

boolean success = sysJobRepository.deleteSysJobById(req.getJobId());if (!success) return OperationResUtils.fail("删除失败");else{ if (existedSysJob.getJobStatus().equals(SysJobStatus.NORMAL.ordinal())) { SchedulingRunnable task = new SchedulingRunnable(existedSysJob.getBeanName(), existedSysJob.getMethodName(), existedSysJob.getMethodParams()); cronTaskRegistrar.removeCronTask(task); }}
return OperationResUtils.success();

定时任务启动/停止状态切换

if (existedSysJob.getJobStatus().equals(SysJobStatus.NORMAL.ordinal())) { SchedulingRunnable task = new SchedulingRunnable(existedSysJob.getBeanName(), existedSysJob.getMethodName(), existedSysJob.getMethodParams()); cronTaskRegistrar.addCronTask(task, existedSysJob.getCronExpression());} else { SchedulingRunnable task = new SchedulingRunnable(existedSysJob.getBeanName(), existedSysJob.getMethodName(), existedSysJob.getMethodParams()); cronTaskRegistrar.removeCronTask(task);}

添加实现了CommandLineRunner接口的SysJobRunner类,当spring boot项目启动完成后,加载数据库里状态为正常的定时任务。

@Servicepublic class SysJobRunner implements CommandLineRunner {
private static final Logger logger = LoggerFactory.getLogger(SysJobRunner.class);
@Autowired private ISysJobRepository sysJobRepository;
@Autowired private CronTaskRegistrar cronTaskRegistrar;
@Override public void run(String... args) { // 初始加载数据库里状态为正常的定时任务 List<SysJobPO> jobList = sysJobRepository.getSysJobListByStatus(SysJobStatus.NORMAL.ordinal()); if (CollectionUtils.isNotEmpty(jobList)) { for (SysJobPO job : jobList) { SchedulingRunnable task = new SchedulingRunnable(job.getBeanName(), job.getMethodName(), job.getMethodParams()); cronTaskRegistrar.addCronTask(task, job.getCronExpression()); }
logger.info("定时任务已加载完毕..."); } }}

工具类SpringContextUtils,用来从spring容器里获取bean

@Componentpublic class SpringContextUtils implements ApplicationContextAware {
private static ApplicationContext applicationContext;
@Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { SpringContextUtils.applicationContext = applicationContext; }
public static Object getBean(String name) { return applicationContext.getBean(name); }
public static <T> T getBean(Class<T> requiredType) { return applicationContext.getBean(requiredType); }
public static <T> T getBean(String name, Class<T> requiredType) { return applicationContext.getBean(name, requiredType); }
public static boolean containsBean(String name) { return applicationContext.containsBean(name); }
public static boolean isSingleton(String name) { return applicationContext.isSingleton(name); }
public static Class<? extends Object> getType(String name) { return applicationContext.getType(name); }}
来源:jianshu.com/p/0f68936393fd


近期技术热文

1、7 个 Spring Cloud 实战项目推荐,赶紧收藏!

2、卧槽!Java 中的 xx ≠ null 是什么鬼东西?第一次见。。。

3、为什么我不建议你用阿里巴巴Java规范,而使用 Google Guava 编程?

4、为什么索引可以让查询变快,你有思考过吗?


点击下方公众号
回复关键字【666
领取资料


我就知道你会点赞+“在看”

: . Video Mini Program Like ,轻点两下取消赞 Wow ,轻点两下取消在看

您可能也对以下帖子感兴趣

文章有问题?点此查看未经处理的缓存