Question

目前我正在使用以下配置来安排我的调度程序。

 @Schedule(second ="1/10", minute = "*", hour = "*")
 private void scheduleUser() {      
    try {
        new UserFacade().insertUserInfo();            
    } catch (Exception e) {
        logger.error("Error in : " + e);
    }
 }

现在我想在运行时设置计时器值而不是硬编码方式。假设我有一个bean调用Property，它有一个名为frequency的字段。

现在我想为new Property().getFrequency()调度程序设置EJB之类的值。

有没有办法做一些像下面这样的事情？

 @Schedule(second =new Property().getFrequency(), minute = "*", hour = "*")
 private void scheduleUser() {      
    try {
        new UserFacade().insertUserInfo();            
    } catch (Exception e) {
        logger.error("Error in : " + e);
    }
 }

Answer 1

没有注释，没有。您必须使用程序化计时器（Java 7，EE7）：

package com.foo;

import java.util.Date;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.annotation.Resource;
import javax.ejb.EJBException;
import javax.ejb.Singleton;
import javax.ejb.Timeout;
import javax.ejb.Timer;
import javax.ejb.TimerService;

@Singleton
public class MyTimer {
    @Resource
    private TimerService timerService;

    @Timeout
    public void timeout(Timer timer) {
        System.out.println("TimerBean: timeout occurred");
    }

    public void schedule(Date start, long intervalMilis) {
        try{
            timerService.createTimer(start, intervalMilis, "my timer");            
        } catch (EJBException|IllegalArgumentException|IllegalStateException ex)  {
            Logger.getLogger(MyTimer.class.getName()).log(Level.WARNING, ex.getMessage(), ex);
        }
    }
}

有关详细信息，请参阅https://docs.oracle.com/javaee/7/tutorial/ejb-basicexamples004.htm。

Answer 2

类似于Vegard提交的答案，除了使用ScheduleExpression的答案。更多信息Beginning Java EE 7 book

import javax.ejb.ScheduleExpression;

@Singleton
public class MyTimer {

    @Resource
    private TimerService timerService;

    @Timeout
    public void timeout(Timer timer) {
        System.out.println("TimerBean: timeout occurred");
    }

    public void schedule(String DOW, String H, String M, String S) {
        try{
            ScheduleExpression scheduleExpression = new ScheduleExpression();
            scheduleExpression.dayOfWeek(DOW); 
            scheduleExpression.hour(H); 
            scheduleExpression.minute(M); 
            scheduleExpression.second(S); 

            timerService.createCalendarTimer(scheduleExpression, new TimerConfig(this, false));
        } catch (EJBException|IllegalArgumentException|IllegalStateException ex)  {
            Logger.getLogger(MyTimer.class.getName()).log(Level.WARNING, ex.getMessage(), ex);
        }
    }

}

如何在EJB调度中设置计时器值？

2 个答案: