答案

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。

定時任務列表頁

定時任務執(zhí)行日志

添加執(zhí)行定時任務的線程池配置類

@Configurationpublic 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。

@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。

@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) {        // 初始加載數(shù)據(jù)庫里狀態(tài)為正常的定時任務        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容器里獲取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);    }}

來源：jianshu.com/p/0f68936393fd

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

Spring Boot 實現(xiàn)定時任務的動態(tài)增刪啟停！