java - 每 30 秒执行一次 Java 类的最简单方法是什么？

Question

我一直在阅读有关 java/spring/hibernate 并通过“虚拟”示例进行工作，所以我告诉我的 friend 为我推荐一些更难的东西，现在我被困住了.. 这是我最简单的类(class)能想到

package spring.com.practice;

public class Pitcher {

    private String shout;

    public String getShout() {
        return shout;
    }

    public void setShout(String shout) {
        this.shout = shout;
    }

    public void voice()
    {
        System.out.println(getShout());
    }

}

通过从spring beans调用metod voice() 打印出一些东西的最简单方法是什么，并且每30秒重复一次可以说，这是我到目前为止所得到的:

<bean id="simpleTrigger" class="org.springframework.scheduling.quartz.SimpleTriggerBean">
    <property name="jobDetail" ref="jobSchedulerDetail" />
    <property name="startDelay" value="0" />
    <property name="repeatInterval" value="30" />
</bean>


<bean class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
    <property name="schedulerName" value="pitcherScheduler" />
    <property name="triggers">
        <list>
            <ref bean="simpleTrigger" />
        </list>
    </property>
</bean>
 <bean id="pitcher" class="spring.com.practice.Pitcher">
 <property name="shout" value="I started executing..."></property>
 </bean>

是的，我正在尝试在 Jboss 5 上运行它，我正在使用 maven 构建一个项目。

我得到了一些建议，我的应用程序上下文现在看起来像:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns:sched="http://www.springinaction.com/schema/sched"
   xsi:schemaLocation="http://www.springframework.org/schema/beans 
       http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
       http://www.springinaction.com/schema/sched
       http://www.springinaction.com/schema/sched-1.0.xsd"
       default-lazy-init="true">

   <bean id="stuffDoer" class="spring.com.practice">
   <property name="shout" value="I'm executing"/>
   </bean>

  <sched:timer-job
       target-bean="stuffDoer"
       target-method="voice"
       interval="5000" 
       start-delay="1000"
       repeat-count="10" />

</beans>

这是我的 web.xml:

<web-app id="simple-webapp" version="2.4"
    xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
    <display-name>spring app</display-name>
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
            /WEB-INF/conf/applicationContext.xml
</param-value>
    </context-param>
    <context-param>
        <param-name>log4jConfigLocation</param-name>
        <param-value>/WEB-INF/log4j.properties</param-value>
    </context-param>
    <listener>
        <listener-class>
            org.springframework.web.util.Log4jConfigListener
</listener-class>
    </listener>
    <listener>
        <listener-class>
            org.springframework.web.context.ContextLoaderListener
</listener-class>
    </listener>
</web-app>

现在我得到了这个异常(exception):

12:35:51,657 ERROR [01-SNAPSHOT]] Error configuring application listener of class org.springframework.web.context.ContextLoaderListener
java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener

我没有意识到每 30 秒执行一次 hello world 之类的东西会这么复杂

Answer 1

我不会为 Quartz 烦恼，对于这么简单的事情来说，它是矫枉过正的。 Java5自带调度器，已经够用了。

Pre-Spring 3，这是最简单的方法:

<bean class="org.springframework.scheduling.concurrent.ScheduledExecutorFactoryBean">
    <property name="scheduledExecutorTasks">
        <list>
            <bean class="org.springframework.scheduling.concurrent.ScheduledExecutorTask">
                <property name="period" value="30000"/>
                <property name="runnable">
                    <bean class="org.springframework.scheduling.support.MethodInvokingRunnable">
                        <property name="targetObject" ref="pitcher"/>
                        <property name="targetMethod" value="voice"/>
                    </bean>
                </property>
            </bean>
        </list>
    </property>
</bean>

使用 Spring 3，它可以非常简单:

@Scheduled(fixedRate=30000)
public void voice() {
    System.out.println(getShout());
}

和

<beans xmlns="http://www.springframework.org/schema/beans"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xmlns:task="http://www.springframework.org/schema/task"
           xsi:schemaLocation="
                http://www.springframework.org/schema/beans   http://www.springframework.org/schema/beans/spring-beans.xsd
                http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task.xsd
           "> 

  <bean id="pitcher" class="spring.com.practice.Pitcher">
     <property name="shout" value="I started executing..."></property>
  </bean>

  <task:annotation-driven/>

</beans>