@Data
@AllArgsConstructor
@NoArgsConstructor
public class TaskEntity {
  /**
   * 任務(wù)id
   */
  private int taskId;
  /**
   * 任務(wù)說明
   */
  private String desc;
  /**
   * cron 表達(dá)式
   */
  private String expression;
}

public interface TaskService {

  void HandlerJob();

  Integer jobId();

}

@Service
public class TaskServiceJob1Impl implements TaskService {
  @Override
  public void HandlerJob() {
    System.out.println("------job1 開始執(zhí)行---------："+new Date());

    System.out.println(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "  " + Thread.currentThread().getName() + "  任務(wù)一啟動");
    try {
      Thread.sleep(10000);//任務(wù)耗時10秒
    } catch (InterruptedException e) {
      e.printStackTrace();
    }
    System.out.println(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "  " + Thread.currentThread().getName() + "  結(jié)束");

  }

  @Override
  public Integer jobId() {
    return 1;
  }
}

@Slf4j
@Component
public class TaskSolverChooser implements ApplicationContextAware {

  private ApplicationContext applicationContext;

  private Map<Integer, TaskService> chooseMap = new HashMap<>(16);

  /**
   * 拿到spring context 上下文
   */
  @Override
  public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
    this.applicationContext = applicationContext;
  }

  @PostConstruct
  private void registerToTaskSolver(){
    Map<String, TaskService> taskServiceMap = applicationContext.getBeansOfType(TaskService.class);
    for (TaskService value : taskServiceMap.values()) {
      chooseMap.put(value.jobId(), value);
      log.info("task {} 處理器: {} 注冊成功",new Object[]{value.jobId(),value});
    }
  }

  /**
   * 獲取需要的job
   */
  public TaskService getTask(Integer jobId){
    return chooseMap.get(jobId);
  }
}

@Component
public class MyScheduledTask implements SchedulingConfigurer {

  private volatile ScheduledTaskRegistrar registrar;

  private final ConcurrentHashMap<Integer, ScheduledFuture<?>> scheduledFutures = new ConcurrentHashMap<>();
  private final ConcurrentHashMap<Integer, CronTask> cronTasks = new ConcurrentHashMap<>();

  @Autowired
  private TaskSolverChooser taskSolverChooser;

  @Override
  public void configureTasks(ScheduledTaskRegistrar registrar) {

    //設(shè)置20個線程,默認(rèn)單線程,如果不設(shè)置的話，不能同時并發(fā)執(zhí)行任務(wù)
    registrar.setScheduler(Executors.newScheduledThreadPool(10));
    this.registrar = registrar;
  }

  /**
   * 修改 cron 需要 調(diào)用該方法
   */
  public void refresh(List<TaskEntity> tasks){
    //取消已經(jīng)刪除的策略任務(wù)
    Set<Integer> sids = scheduledFutures.keySet();
    for (Integer sid : sids) {
      if(!exists(tasks, sid)){
        scheduledFutures.get(sid).cancel(false);
      }
    }
    for (TaskEntity TaskEntity : tasks) {
      String expression = TaskEntity.getExpression();
      //計劃任務(wù)表達(dá)式為空則跳過
      if(!StringUtils.hasLength(expression)){
        continue;
      }
      //計劃任務(wù)已存在并且表達(dá)式未發(fā)生變化則跳過
      if (scheduledFutures.containsKey(TaskEntity.getTaskId())
          && cronTasks.get(TaskEntity.getTaskId()).getExpression().equals(expression)) {
        continue;
      }
      //如果策略執(zhí)行時間發(fā)生了變化，則取消當(dāng)前策略的任務(wù)
      if(scheduledFutures.containsKey(TaskEntity.getTaskId())){
        scheduledFutures.get(TaskEntity.getTaskId()).cancel(false);
        scheduledFutures.remove(TaskEntity.getTaskId());
        cronTasks.remove(TaskEntity.getTaskId());
      }
      //業(yè)務(wù)邏輯處理
      CronTask task = cronTask(TaskEntity, expression);


      //執(zhí)行業(yè)務(wù)
      ScheduledFuture<?> future = registrar.getScheduler().schedule(task.getRunnable(), task.getTrigger());
      cronTasks.put(TaskEntity.getTaskId(), task);
      scheduledFutures.put(TaskEntity.getTaskId(), future);
    }
  }

  /**
   * 停止 cron 運行
   */
  public void stop(List<TaskEntity> tasks){
    tasks.forEach(item->{
      if (scheduledFutures.containsKey(item.getTaskId())) {
        // mayInterruptIfRunning設(shè)成false話，不允許在線程運行時中斷，設(shè)成true的話就允許。
        scheduledFutures.get(item.getTaskId()).cancel(false);
        scheduledFutures.remove(item.getTaskId());
      }
    });
  }

  /**
   * 業(yè)務(wù)邏輯處理
   */
  public CronTask cronTask(TaskEntity TaskEntity, String expression) {
    return new CronTask(() -> {
          //每個計劃任務(wù)實際需要執(zhí)行的具體業(yè)務(wù)邏輯
          //采用策略，模式 ，執(zhí)行我們的job
          taskSolverChooser.getTask(TaskEntity.getTaskId()).HandlerJob();
        }, expression);
  }

  private boolean exists(List<TaskEntity> tasks, Integer tid){
    for(TaskEntity TaskEntity:tasks){
      if(TaskEntity.getTaskId() == tid){
        return true;
      }
    }
    return false;
  }

  @PreDestroy
  public void destroy() {
    this.registrar.destroy();
  }

}

@Component
public class StartInitTask implements CommandLineRunner {

  @Autowired
  private MyScheduledTask myScheduledTask;

  @Override
  public void run(String... args) throws Exception {
    List<TaskEntity> list = Arrays.asList(
        new TaskEntity(1, "測試1", "0/1 * * * * ?"),
        new TaskEntity(2, "測試2", "0/1 * * * * ?")
    );
    myScheduledTask.refresh(list);
  }
}

@RestController
public class StartController {

  @Autowired
  private MyScheduledTask scheduledTask;

  @PostMapping(value = "/startOrChangeCron")
  public String changeCron(@RequestBody List<TaskEntity> list){
    if (CollectionUtils.isEmpty(list)) {
      // 這里模擬存在數(shù)據(jù)庫的數(shù)據(jù)
      list = Arrays.asList(
          new TaskEntity(1, "測試1","0/1 * * * * ?") ,
          new TaskEntity(2, "測試2","0/1 * * * * ?")
      );
    }
    scheduledTask.refresh(list);
    return "task任務(wù):" + list.toString() + "已經(jīng)開始運行";
  }

  @PostMapping(value = "/stopCron")
  public String stopCron(@RequestBody List<TaskEntity> list){
    if (CollectionUtils.isEmpty(list)) {
      // 這里模擬將要停止的cron可通過前端傳來
      list = Arrays.asList(
          new TaskEntity(1, "測試1","0/1 * * * * ?") ,
          new TaskEntity(2, "測試2","0/1 * * * * ?")
      );
    }
    scheduledTask.stop(list);
    List<Integer> collect = list.stream().map(TaskEntity::getTaskId).collect(Collectors.toList());
    return "task任務(wù):" + collect.toString() + "已經(jīng)停止啟動";
  }

}