要實現動態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，發現可以通過改造這個類就能實現動態增刪啟停定時任務功能。

添加執行定時任務的線程池配置類

@Configuration
publicclassSchedulingConfig{
@Bean
publicTaskSchedulertaskScheduler(){
ThreadPoolTaskSchedulertaskScheduler=newThreadPoolTaskScheduler();
//定時任務執行線程池核心線程數
taskScheduler.setPoolSize(4);
taskScheduler.setRemoveOnCancelPolicy(true);
taskScheduler.setThreadNamePrefix("TaskSchedulerThreadPool-");
returntaskScheduler;
}
}

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

publicfinalclassScheduledTask{

volatileScheduledFuturefuture;

/**
*取消定時任務
*/
publicvoidcancel(){
ScheduledFuturefuture=this.future;
if(future!=null){
future.cancel(true);
}
}
}

添加Runnable接口實現類，被定時任務線程池調用，用來執行指定bean里面的方法。

publicclassSchedulingRunnableimplementsRunnable{

privatestaticfinalLoggerlogger=LoggerFactory.getLogger(SchedulingRunnable.class);

privateStringbeanName;

privateStringmethodName;

privateStringparams;

publicSchedulingRunnable(StringbeanName,StringmethodName){
this(beanName,methodName,null);
}

publicSchedulingRunnable(StringbeanName,StringmethodName,Stringparams){
this.beanName=beanName;
this.methodName=methodName;
this.params=params;
}

@Override
publicvoidrun(){
logger.info("定時任務開始執行- bean：{}，方法：{}，參數：{}",beanName,methodName,params);
longstartTime=System.currentTimeMillis();

try{
Objecttarget=SpringContextUtils.getBean(beanName);

Methodmethod=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(Exceptionex){
logger.error(String.format("定時任務執行異常- bean：%s，方法：%s，參數：%s ",beanName,methodName,params),ex);
}

longtimes=System.currentTimeMillis()-startTime;
logger.info("定時任務執行結束- bean：{}，方法：{}，參數：{}，耗時：{}毫秒",beanName,methodName,params,times);
}

@Override
publicbooleanequals(Objecto){
if(this==o)returntrue;
if(o==null||getClass()!=o.getClass())returnfalse;
SchedulingRunnablethat=(SchedulingRunnable)o;
if(params==null){
returnbeanName.equals(that.beanName)&&
methodName.equals(that.methodName)&&
that.params==null;
}

returnbeanName.equals(that.beanName)&&
methodName.equals(that.methodName)&&
params.equals(that.params);
}

@Override
publicinthashCode(){
if(params==null){
returnObjects.hash(beanName,methodName);
}

returnObjects.hash(beanName,methodName,params);
}
}

添加定時任務注冊類，用來增加、刪除定時任務。

@Component
publicclassCronTaskRegistrarimplementsDisposableBean{

privatefinalMapscheduledTasks=newConcurrentHashMap<>(16);

@Autowired
privateTaskSchedulertaskScheduler;

publicTaskSchedulergetScheduler(){
returnthis.taskScheduler;
}

publicvoidaddCronTask(Runnabletask,StringcronExpression){
addCronTask(newCronTask(task,cronExpression));
}

publicvoidaddCronTask(CronTaskcronTask){
if(cronTask!=null){
Runnabletask=cronTask.getRunnable();
if(this.scheduledTasks.containsKey(task)){
removeCronTask(task);
}

this.scheduledTasks.put(task,scheduleCronTask(cronTask));
}
}

publicvoidremoveCronTask(Runnabletask){
ScheduledTaskscheduledTask=this.scheduledTasks.remove(task);
if(scheduledTask!=null)
scheduledTask.cancel();
}

publicScheduledTaskscheduleCronTask(CronTaskcronTask){
ScheduledTaskscheduledTask=newScheduledTask();
scheduledTask.future=this.taskScheduler.schedule(cronTask.getRunnable(),cronTask.getTrigger());

returnscheduledTask;
}


@Override
publicvoiddestroy(){
for(ScheduledTasktask:this.scheduledTasks.values()){
task.cancel();
}

this.scheduledTasks.clear();
}
}

添加定時任務示例類

@Component("demoTask")
publicclassDemoTask{
publicvoidtaskWithParams(Stringparams){
System.out.println("執行有參示例任務："+params);
}

publicvoidtaskNoParams(){
System.out.println("執行無參示例任務");
}
}

定時任務數據庫表設計

添加定時任務實體類

publicclassSysJobPO{
/**
*任務ID
*/
privateIntegerjobId;
/**
*bean名稱
*/
privateStringbeanName;
/**
*方法名稱
*/
privateStringmethodName;
/**
*方法參數
*/
privateStringmethodParams;
/**
*cron表達式
*/
privateStringcronExpression;
/**
*狀態（1正常0暫停）
*/
privateIntegerjobStatus;
/**
*備注
*/
privateStringremark;
/**
*創建時間
*/
privateDatecreateTime;
/**
*更新時間
*/
privateDateupdateTime;

publicIntegergetJobId(){
returnjobId;
}

publicvoidsetJobId(IntegerjobId){
this.jobId=jobId;
}

publicStringgetBeanName(){
returnbeanName;
}

publicvoidsetBeanName(StringbeanName){
this.beanName=beanName;
}

publicStringgetMethodName(){
returnmethodName;
}

publicvoidsetMethodName(StringmethodName){
this.methodName=methodName;
}

publicStringgetMethodParams(){
returnmethodParams;
}

publicvoidsetMethodParams(StringmethodParams){
this.methodParams=methodParams;
}

publicStringgetCronExpression(){
returncronExpression;
}

publicvoidsetCronExpression(StringcronExpression){
this.cronExpression=cronExpression;
}

publicIntegergetJobStatus(){
returnjobStatus;
}

publicvoidsetJobStatus(IntegerjobStatus){
this.jobStatus=jobStatus;
}

publicStringgetRemark(){
returnremark;
}

publicvoidsetRemark(Stringremark){
this.remark=remark;
}

publicDategetCreateTime(){
returncreateTime;
}

publicvoidsetCreateTime(DatecreateTime){
this.createTime=createTime;
}

publicDategetUpdateTime(){
returnupdateTime;
}

publicvoidsetUpdateTime(DateupdateTime){
this.updateTime=updateTime;
}

}

booleansuccess=sysJobRepository.addSysJob(sysJob);
if(!success)
returnOperationResUtils.fail("新增失敗");
else{
if(sysJob.getJobStatus().equals(SysJobStatus.NORMAL.ordinal())){
SchedulingRunnabletask=newSchedulingRunnable(sysJob.getBeanName(),sysJob.getMethodName(),sysJob.getMethodParams());
cronTaskRegistrar.addCronTask(task,sysJob.getCronExpression());
}
}

returnOperationResUtils.success();

修改定時任務，先移除原來的任務，再啟動新任務

booleansuccess=sysJobRepository.editSysJob(sysJob);
if(!success)
returnOperationResUtils.fail("編輯失敗");
else{
//先移除再添加
if(existedSysJob.getJobStatus().equals(SysJobStatus.NORMAL.ordinal())){
SchedulingRunnabletask=newSchedulingRunnable(existedSysJob.getBeanName(),existedSysJob.getMethodName(),existedSysJob.getMethodParams());
cronTaskRegistrar.removeCronTask(task);
}

if(sysJob.getJobStatus().equals(SysJobStatus.NORMAL.ordinal())){
SchedulingRunnabletask=newSchedulingRunnable(sysJob.getBeanName(),sysJob.getMethodName(),sysJob.getMethodParams());
cronTaskRegistrar.addCronTask(task,sysJob.getCronExpression());
}
}

returnOperationResUtils.success();

刪除定時任務

booleansuccess=sysJobRepository.deleteSysJobById(req.getJobId());
if(!success)
returnOperationResUtils.fail("刪除失敗");
else{
if(existedSysJob.getJobStatus().equals(SysJobStatus.NORMAL.ordinal())){
SchedulingRunnabletask=newSchedulingRunnable(existedSysJob.getBeanName(),existedSysJob.getMethodName(),existedSysJob.getMethodParams());
cronTaskRegistrar.removeCronTask(task);
}
}

returnOperationResUtils.success();

定時任務啟動/停止狀態切換

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

添加實現了CommandLineRunner接口的SysJobRunner類，當spring boot項目啟動完成后，加載數據庫里狀態為正常的定時任務。

@Service
publicclassSysJobRunnerimplementsCommandLineRunner{

privatestaticfinalLoggerlogger=LoggerFactory.getLogger(SysJobRunner.class);

@Autowired
privateISysJobRepositorysysJobRepository;

@Autowired
privateCronTaskRegistrarcronTaskRegistrar;

@Override
publicvoidrun(String...args){
//初始加載數據庫里狀態為正常的定時任務
ListjobList=sysJobRepository.getSysJobListByStatus(SysJobStatus.NORMAL.ordinal());
if(CollectionUtils.isNotEmpty(jobList)){
for(SysJobPOjob:jobList){
SchedulingRunnabletask=newSchedulingRunnable(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
publicclassSpringContextUtilsimplementsApplicationContextAware{

privatestaticApplicationContextapplicationContext;

@Override
publicvoidsetApplicationContext(ApplicationContextapplicationContext)
throwsBeansException{
SpringContextUtils.applicationContext=applicationContext;
}

publicstaticObjectgetBean(Stringname){
returnapplicationContext.getBean(name);
}

publicstaticTgetBean(ClassrequiredType){
returnapplicationContext.getBean(requiredType);
}

publicstaticTgetBean(Stringname,ClassrequiredType){
returnapplicationContext.getBean(name,requiredType);
}

publicstaticbooleancontainsBean(Stringname){
returnapplicationContext.containsBean(name);
}

publicstaticbooleanisSingleton(Stringname){
returnapplicationContext.isSingleton(name);
}

publicstaticClassgetType(Stringname){
returnapplicationContext.getType(name);
}
}

本文完，參考本文代碼可成功運行，親測！