SpringBoot如何实现动态增删启停定时任务

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。

添加执行定时任务的线程池配置类

@Configuration
publicclassSchedulingConfig{
@Bean
publicTaskSchedulertaskScheduler(){
ThreadPoolTaskSchedulertaskScheduler=newThreadPoolTaskScheduler();
//定时任务执行线程池核心线程数
taskScheduler.setPoolSize(4);
taskScheduler.setRemoveOnCancelPolicy(true);
taskScheduler.setThreadNamePrefix("TaskSchedulerThreadPool-");
returntaskScheduler;
}
}

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

publicfinalclassScheduledTask{

volatileScheduledFuturefuture;

/**
*取消定时任务
*/
publicvoidcancel(){
ScheduledFuturefuture=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。

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("定时任务开始执行- bean：{}，方法：{}，参数：{}",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("定时任务执行异常- bean：%s，方法：%s，参数：%s ",beanName,methodName,params),ex);
}

longtimes=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
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);
}
}

添加定时任务注册类，用来增加、删除定时任务。

@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();
}
}

添加定时任务示例类

@Component("demoTask")
publicclassDemoTask{
publicvoidtaskWithParams(Stringparams){
System.out.println("执行有参示例任务："+params);
}

publicvoidtaskNoParams(){
System.out.println("执行无参示例任务");
}
}

定时任务数据库表设计

添加定时任务实体类

publicclassSysJobPO{
/**
*任务ID
*/
privateIntegerjobId;
/**
*bean名称
*/
privateStringbeanName;
/**
*方法名称
*/
privateStringmethodName;
/**
*方法参数
*/
privateStringmethodParams;
/**
*cron表达式
*/
privateStringcronExpression;
/**
*状态（1正常0暂停）
*/
privateIntegerjobStatus;
/**
*备注
*/
privateStringremark;
/**
*创建时间
*/
privateDatecreateTime;
/**
*更新时间
*/
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("新增失败");
else{
if(sysJob.getJobStatus().equals(SysJobStatus.NORMAL.ordinal())){
SchedulingRunnabletask=newSchedulingRunnable(sysJob.getBeanName(),sysJob.getMethodName(),sysJob.getMethodParams());
cronTaskRegistrar.addCronTask(task,sysJob.getCronExpression());
}
}

returnOperationResUtils.success();

修改定时任务，先移除原来的任务，再启动新任务

booleansuccess=sysJobRepository.editSysJob(sysJob);
if(!success)
returnOperationResUtils.fail("编辑失败");
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();

删除定时任务

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

returnOperationResUtils.success();

定时任务启动/停止状态切换

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。

@Service
publicclassSysJobRunnerimplementsCommandLineRunner{

privatestaticfinalLoggerlogger=LoggerFactory.getLogger(SysJobRunner.class);

@Autowired
privateISysJobRepositorysysJobRepository;

@Autowired
privateCronTaskRegistrarcronTaskRegistrar;

@Override
publicvoidrun(String...args){
//初始加载数据库里状态为正常的定时任务
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("定时任务已加载完毕...");
}
}
}

工具类SpringContextUtils，用来从spring容器里获取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，参考本文代码可成功运行，亲测！