SpringBoot 實現動態增刪啓停定時任務
來源：www.jianshu.com/p/0f68936393fd
在 spring boot 項目中，可以通過@EnableScheduling註解和 @Scheduled 註解實現定時任務，也可以通過 SchedulingConfigurer 接口來實現定時任務。但是這兩種方式不能動態添加、刪除、啓動、停止任務。
要實現動態增刪啓停定時任務功能，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，儘量少的依賴其它框架，避免項目過於臃腫和複雜。
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啓停定時任務功能。
定時任務列表頁
定時任務執行日誌
添加執行定時任務的線程池配置類
@Configuration
public class SchedulingConfig {
@Bean
public TaskScheduler taskScheduler() {
ThreadPoolTaskScheduler taskScheduler = new ThreadPoolTaskScheduler();
// 定時任務執行線程池核心線程數
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 接口實現類，被定時任務線程池調用，用來執行指定 bean 裏面的方法。
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("定時任務開始執行 - bean：{}，方法：{}，參數：{}", 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("定時任務執行異常 - bean：%s，方法：%s，參數：%s ", beanName, methodName, params), ex);
}
long times = 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
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);
}
}添加定時任務註冊類，用來增加、刪除定時任務。
@Component
public 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();
}
}添加定時任務示例類
@Component("demoTask")
public class DemoTask {
public void taskWithParams(String params) {
System.out.println("執行有參示例任務：" + params);
}
public void taskNoParams() {
System.out.println("執行無參示例任務");
}
}定時任務數據庫表設計
定時任務數據庫表設計
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
*/
private String methodParams;
/**
* cron表達式
*/
private String cronExpression;
/**
* 狀態（1正常 0暫停）
*/
private Integer jobStatus;
/**
* 備註
*/
private String remark;
/**
* 創建時間
*/
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
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，再啓動新任務
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();定時任務啓動 / 停止狀態切換
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);
}添加實現了 CommandLineRunner 接口的 SysJobRunner 類，當 spring boot 項目啓動完成後，加載數據庫裏狀態爲正常的定時任務。另外，歡迎關注公衆號 Java 筆記蝦，後臺回覆 “後端面試”，送你一份面試題寶典！
@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) {
// 初始加載數據庫裏狀態爲正常的定時任務
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("定時任務已加載完畢...");
}
}
}工具類 SpringContextUtils，用來從 spring 容器裏獲取 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> 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);
}
}本文完，參考本文代碼可成功運行，親測！
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來源：https://mp.weixin.qq.com/s/Hh2UK3mImVdj87bpLRLkyQ