JSF-2应用程序中的服务器端计时器 [英] Server side timer in a JSF-2 application

问题描述

在我正在处理的JSF-2应用程序中，我需要在用户执行操作时启动服务器端Timer.
此计时器必须与应用程序本身相关，因此在关闭用户会话时必须保留该计时器.
为了解决此问题，我认为可以使用java.util.Timer类在Application范围的Bean中实例化计时器对象.
会是一个好的解决方案吗?还有其他更好的方法可以做到这一点吗?谢谢

in the JSF-2 application I'm working on, I need to start a server side Timer when a user does an action.
This timer must be related to the application itself, so it must survive when the user session is closed.
To solve this problem, I thought to use java.util.Timer class instantiating the timer object in an Application scoped bean.
Could it be a good solution? Are there other better ways to achive this? Thanks

推荐答案

没有ejb容器

如果您的容器不具有ejb功能(tomcat，码头等)，则可以使用石英调度程序库: http ://quartz-scheduler.org/

If your container doesnt have ejb capabilities (tomcat, jetty etc..), you can go with quartz scheduler library: http://quartz-scheduler.org/

他们还有一些不错的代码示例: http://quartz- scheduler.org/documentation/quartz-2.1.x/examples/Example1

They also has some nice code samples: http://quartz-scheduler.org/documentation/quartz-2.1.x/examples/Example1

EJB 3.1

如果您的应用程序服务器具有EJB 3.1(glassfish，Jboss)，则存在Java ee标准的创建计时器的方法.主要查看@Schedule和@Timeout批注.

If your app-server have a EJB 3.1 (glassfish, Jboss), there is a java ee standard way of creating timers. Mainly look into the @Schedule and @Timeout annotations.

类似的情况可能会覆盖您的用例(注释为@Timeout的方法将在计时器用尽时被调用)

Something like this might cover your usecase (method annotated @Timeout will be invoked when timer runs out)

import javax.annotation.Resource;
import javax.ejb.Stateless;
import javax.ejb.Timeout;
import javax.ejb.Timer;
import javax.ejb.TimerConfig;
import javax.ejb.TimerService;

@Stateless
public class TimerBean {
    @Resource
    protected TimerService timerService;

    @Timeout
    public void timeoutHandler(Timer timer) {
        String name = timer.getInfo().toString();
        System.out.println("Timer name=" + name);
    }

    public void startTimer(long initialExpiration, long interval, String name){      
        TimerConfig config = new TimerConfig();
        config.setInfo(name);
        config.setPersistent(false);
        timerService.createIntervalTimer(initialExpiration, interval, config);
    }
}

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