點擊上方藍色“小哈學Java”，選擇“設為星標”

回復“資源”獲取獨家整理的學習資料！

來源：jianshu.com/p/0f68936393fd

添加執(zhí)行定時任務的線程池配置類
添加定時任務示例類
定時任務數(shù)據(jù)庫表設計
添加定時任務實體類
新增定時任務

在spring boot項目中，可以通過@EnableScheduling注解和@Scheduled注解實現(xiàn)定時任務，也可以通過SchedulingConfigurer接口來實現(xiàn)定時任務。但是這兩種方式不能動態(tài)添加、刪除、啟動、停止任務。

要實現(xiàn)動態(tài)增刪啟停定時任務功能，比較廣泛的做法是集成Quartz框架。但是本人的開發(fā)原則是：在滿足項目需求的情況下，盡量少的依賴其它框架，避免項目過于臃腫和復雜。

查看spring-context這個jar包中org.springframework.scheduling.ScheduledTaskRegistrar這個類的源代碼，發(fā)現(xiàn)可以通過改造這個類就能實現(xiàn)動態(tài)增刪啟停定時任務功能。

添加執(zhí)行定時任務的線程池配置類

@Configuration
public?class?SchedulingConfig?{
????@Bean
????public?TaskScheduler?taskScheduler()?{
????????ThreadPoolTaskScheduler?taskScheduler?=?new?ThreadPoolTaskScheduler();
????????//?定時任務執(zhí)行線程池核心線程數(shù)
????????taskScheduler.setPoolSize(4);
????????taskScheduler.setRemoveOnCancelPolicy(true);
????????taskScheduler.setThreadNamePrefix("TaskSchedulerThreadPool-");
????????return?taskScheduler;
????}
}

添加ScheduledFuture的包裝類。ScheduledFuture是ScheduledExecutorService定時任務線程池的執(zhí)行結果。

public?final?class?ScheduledTask?{

????volatile?ScheduledFuture?future;

????/**
?????*?取消定時任務
?????*/
????public?void?cancel()?{
????????ScheduledFuture?future?=?this.future;
????????if?(future?!=?null)?{
????????????future.cancel(true);
????????}
????}
}

添加Runnable接口實現(xiàn)類，被定時任務線程池調用，用來執(zhí)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("定時任務開始執(zhí)行?- bean：{}，方法：{}，參數(shù)：{}",?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("定時任務執(zhí)行異常?- bean：%s，方法：%s，參數(shù)：%s ",?beanName,?methodName,?params),?ex);
????????}

????????long?times?=?System.currentTimeMillis()?-?startTime;
????????logger.info("定時任務執(zhí)行結束?- bean：{}，方法：{}，參數(shù)：{}，耗時：{}?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);
????}
}

添加定時任務注冊類，用來增加、刪除定時任務。

@Component
public?class?CronTaskRegistrar?implements?DisposableBean?{

????private?final?Map?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();
????}
}

添加定時任務示例類

@Component("demoTask")
public?class?DemoTask?{
????public?void?taskWithParams(String?params)?{
????????System.out.println("執(zhí)行有參示例任務："?+?params);
????}

????public?void?taskNoParams()?{
????????System.out.println("執(zhí)行無參示例任務");
????}
}

定時任務數(shù)據(jù)庫表設計

添加定時任務實體類

public?class?SysJobPO?{
????/**
?????*?任務ID
?????*/
????private?Integer?jobId;
????/**
?????*?bean名稱
?????*/
????private?String?beanName;
????/**
?????*?方法名稱
?????*/
????private?String?methodName;
????/**
?????*?方法參數(shù)
?????*/
????private?String?methodParams;
????/**
?????*?cron表達式
?????*/
????private?String?cronExpression;
????/**
?????*?狀態(tài)（1正常?0暫停）
?????*/
????private?Integer?jobStatus;
????/**
?????*?備注
?????*/
????private?String?remark;
????/**
?????*?創(chuàng)建時間
?????*/
????private?Date?createTime;
????/**
?????*?更新時間
?????*/
????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;
????}

}

新增定時任務

boolean?success?=?sysJobRepository.addSysJob(sysJob);
if?(!success)
????return?OperationResUtils.fail("新增失敗");
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();

修改定時任務，先移除原來的任務，再啟動新任務

boolean?success?=?sysJobRepository.editSysJob(sysJob);
if?(!success)
????return?OperationResUtils.fail("編輯失敗");
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();

刪除定時任務

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

return?OperationResUtils.success();

定時任務啟動/停止狀態(tài)切換

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);
}

添加實現(xiàn)了CommandLineRunner接口的SysJobRunner類，當spring boot項目啟動完成后，加載數(shù)據(jù)庫里狀態(tài)為正常的定時任務。

@Service
public?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)?{
????????//?初始加載數(shù)據(jù)庫里狀態(tài)為正常的定時任務
????????List?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("定時任務已加載完畢...");
????????}
????}
}

工具類SpringContextUtils，用來從spring容器里獲取bean

@Component
public?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?getBean(Class?requiredType)?{
????????return?applicationContext.getBean(requiredType);
????}

????public?static??T?getBean(String?name,?Class?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?getType(String?name)?{
????????return?applicationContext.getType(name);
????}
}

END

有熱門推薦?
1.?談談幾個 Spring Cloud 常見面試題及答案
2.?最受歡迎的男友職業(yè)排行榜，程序員擠進前三！
3.?短 URL 服務，怎么設計與實現(xiàn)？
4.?Spring 的 Controller 是單例還是多例？怎么保證并發(fā)的安全？
最近面試BAT，整理一份面試資料《Java面試BATJ通關手冊》，覆蓋了Java核心技術、JVM、Java并發(fā)、SSM、微服務、數(shù)據(jù)庫、數(shù)據(jù)結構等等。
獲取方式：點“在看”，關注公眾號并回復?Java?領取，更多內容陸續(xù)奉上。
文章有幫助的話，在看，轉發(fā)吧。
謝謝支持喲 (*^__^*）

Spring Boot 實現(xiàn)定時任務的動態(tài)增刪啟停！

添加執(zhí)行定時任務的線程池配置類

添加定時任務示例類

定時任務數(shù)據(jù)庫表設計

添加定時任務實體類

新增定時任務