Quartz简介

标签（空格分隔）： Quartz

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QuartzAPI

Scheduler 与调度程序交互的API
Job 执行作业组件要实现的接口
JobDetail 定义作业实例
Trigger 触发器，定义执行给定作业的计划的组件
JobBuilder 定义和构建JobDetail实例
TriggerBuilder 定义和构建触发器实例

Job和JobDetail

schedule执行job,会调用job的execute方法

// define the job and tie it to our HelloJob class
  JobDetail job = newJob(HelloJob.class)
      .withIdentity("myJob", "group1") // name "myJob", group "group1"
      .build();

  // Trigger the job to run now, and then every 40 seconds
  Trigger trigger = newTrigger()
      .withIdentity("myTrigger", "group1")
      .startNow()
      .withSchedule(simpleSchedule()
          .withIntervalInSeconds(40)
          .repeatForever())            
      .build();

  // Tell quartz to schedule the job using our trigger
  sched.scheduleJob(job, trigger);

 public class HelloJob implements Job {

    public HelloJob() {
    }

    public void execute(JobExecutionContext context)
      throws JobExecutionException
    {
      System.err.println("Hello!  HelloJob is executing.");
    }
  }

可以使用JobDataMap来存取数据，在构建JobDetail时，可把数据放入JobDataMap

// define the job and tie it to our DumbJob class
  JobDetail job = newJob(DumbJob.class)
      .withIdentity("myJob", "group1") // name "myJob", group "group1"
      .usingJobData("jobSays", "Hello World!")
      .usingJobData("myFloatValue", 3.141f)
      .build();

然后在执行job的过程中可以从JobDataMap中取数据

public class DumbJob implements Job {

    public DumbJob() {
    }

    public void execute(JobExecutionContext context)
      throws JobExecutionException
    {
      JobKey key = context.getJobDetail().getKey();

      JobDataMap dataMap = context.getJobDetail().getJobDataMap();

      String jobSays = dataMap.getString("jobSays");
      float myFloatValue = dataMap.getFloat("myFloatValue");

      System.err.println("Instance " + key + " of DumbJob says: " + jobSays + ", and val is: " + myFloatValue);
    }
  }

@DisallowConcurrentExecution 加到job类上表示不要并发执行
@PersistJobDataAfterExecution 加到job类上表示成功执行job类的execute方法后，更新数据

Triggers

jobkey属性 当trigger触发时执行的job的身份
优先级 可设置优先级，只有同时触发的才会比较优先级
错过触发 如果scheduler关闭了或者线程池里没有可用的线程来执行job，此时的trigger就会miss其触发时间。默认都是用智能机制（smart policy），根据触发器类型和配置动态调整行为。
日历示例 Quartz的Calendar对象可以和trigger关联，排除掉一些节日或者时间

HolidayCalendar cal = new HolidayCalendar();
cal.addExcludedDate( someDate );
cal.addExcludedDate( someOtherDate );

sched.addCalendar("myHolidays", cal, false);


Trigger t = newTrigger()
    .withIdentity("myTrigger")
    .forJob("myJob")
    .withSchedule(dailyAtHourAndMinute(9, 30)) // execute job daily at 9:30
    .modifiedByCalendar("myHolidays") // but not on holidays
    .build();

类型

最常用的是SimpleTrigger和CronTrigger，前者按间隔时间和次数设置，后者按Cron表达式设置

JobStores

用于跟踪“工作数据”：jobs，triggers，日历等

RAMJobStore 最简单性能最高的，保存在RAM中
JDBC JobStore 通过JDBC保存在数据库里