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几个月前，我做了一个简单的应用程序，如果在数据库中找到某些条件，我每天晚上都会运行它来向我的用户发送电子邮件。我使用 Spring 3.1.0 和 Quartz 1.8.5 来实现这一点；到目前为止，一切都很好。

该应用程序部署在 weblogic 服务器中。

上周，我被要求修改应用程序以允许手动命令它通过 URL 运行。

我向它添加了一个 servlet，它运行良好：每次有人调用 URL 时，应用程序就会运行。

但是出现了一个附带效应——每个 servlet 调用也会引发 spring 上下文的重新加载，并创建另一个 Quartz 实例。因此，如果该 servlet 被调用 n 次，当 Quartz 解雇我的工作时，我的应用程序将重复发送 n+1 封电子邮件，而不是仅发送 1 封。

我想了解为什么会发生这种情况以及如何解决这个问题。请问你能帮帮我吗？

以下是我的问题的相关文件。

日志文件摘录，包括应用程序的启动：

28/11/2012 16:37:48 org.springframework.web.context.ContextLoader initWebApplicationContext
INFO: Root WebApplicationContext: initialization started
28/11/2012 16:37:48 org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing Root WebApplicationContext: startup date [Wed Nov 28 16:37:48 BRST 2012]; root of context hierarchy
28/11/2012 16:37:48 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from URL [file:/C:/bea/user_projects/workspaces/app/target/app-1.0.0/WEB-INF/classes/app-context.xml]
28/11/2012 16:37:48 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [app-data-context.xml]
28/11/2012 16:37:48 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [app-scheduler.xml]
28/11/2012 16:37:48 org.springframework.core.io.support.PropertiesLoaderSupport loadProperties
INFO: Loading properties file from class path resource [app.properties]
28/11/2012 16:37:48 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@599bcd: defining beans [org.springframework.beans.factory.config.PropertyPlaceholderConfigurer#0,appDS,job,cronTrigger,org.springframework.scheduling.quartz.SchedulerFactoryBean#0,appDAO,appService,mailerService,appTask, (...)]; root of factory hierarchy
28/11/2012 16:37:50 org.springframework.context.support.DefaultLifecycleProcessor$LifecycleGroup start
INFO: Starting beans in phase 2147483647

**28/11/2012 16:37:50 org.springframework.scheduling.quartz.SchedulerFactoryBean startScheduler
INFO: Starting Quartz Scheduler now**

28/11/2012 16:37:50 org.springframework.web.context.ContextLoader initWebApplicationContext
INFO: Root WebApplicationContext: initialization completed in 2109 ms

每次调用 servlet 时出现的日志文件摘录：

<28/11/2012 16h37min50s BRST> <Notice> <WebLogicServer> <BEA-000360> <Server started in RUNNING mode> 
28/11/2012 16:39:06 org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@11f7458: startup date [Wed Nov 28 16:39:06 BRST 2012]; root of context hierarchy
28/11/2012 16:39:06 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [app-context.xml]
28/11/2012 16:39:06 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [app-data-context.xml]
28/11/2012 16:39:06 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [app-scheduler.xml]
28/11/2012 16:39:06 org.springframework.core.io.support.PropertiesLoaderSupport loadProperties
INFO: Loading properties file from class path resource [app.properties]
28/11/2012 16:39:06 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@10ca001: defining beans [(...)]; root of factory hierarchy
28/11/2012 16:39:06 org.springframework.context.support.DefaultLifecycleProcessor$LifecycleGroup start
INFO: Starting beans in phase 2147483647
**28/11/2012 16:39:06 org.springframework.scheduling.quartz.SchedulerFactoryBean startScheduler
INFO: Starting Quartz Scheduler now**

网页.xml：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    version="2.5">

    <description>generic web.xml</description>

    <!-- ====================================== --> 
    <!--               SPRING                   -->
    <!-- ====================================== --> 
    <!-- Loading Application Bean's. -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath*:app-context.xml</param-value>
    </context-param>

    <listener>
      <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
   </listener>

   <servlet>
        <display-name>appServlet</display-name>
        <servlet-name>appServlet</servlet-name>
        <servlet-class>br.com.app.publicInterface.appServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>appServlet</servlet-name>
        <url-pattern>/appServlet</url-pattern>
    </servlet-mapping>

</web-app>

app-context.xml 摘录：

<?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:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.0.xsd">

    <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
        <property name="locations">
            <list>
               <value>classpath:app.properties</value>
            </list>
       </property>
    </bean>

    <import resource="classpath:app-data-context.xml"/>
    <import resource="classpath:app-scheduler.xml"/>

    <!-- DAOs -->
    <!-- Services -->   
    <!-- tasks -->

</beans>

应用程序调度程序.xml：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd">

    <bean name="job" class="org.springframework.scheduling.quartz.JobDetailBean">
        <property name="jobClass" value="br.com.app.job.QuartzJob" />
        <property name="jobDataAsMap">
            <map>
                <entry key="gerenciadorTasks">
                    <ref bean="gerenciadorTasks" />
                </entry>
            </map>
        </property>
    </bean>

    <bean id="cronTrigger" class="org.springframework.scheduling.quartz.CronTriggerBean">
        <property name="jobDetail" ref="job" />
        <property name="cronExpression" value="${quartz.cronExpression}" />
    </bean>

    <bean class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
        <property name="quartzProperties">
            <props>
                <prop key="org.quartz.scheduler.skipUpdateCheck">true</prop>
                <prop key="org.quartz.jobStore.isClustered">true</prop> 
                <prop key="org.quartz.scheduler.instanceName">NotificadorQuartzScheduler</prop>  
                <prop key="org.quartz.scheduler.instanceId">AUTO</prop> 
            </props>
        </property>
        <property name="triggers">
            <list>
                <ref bean="cronTrigger" />
            </list>
        </property>
    </bean>

</beans>

AppServlet 源代码：

public class AppServlet extends HttpServlet   {

    private static final long serialVersionUID = 7213474106234238692L;

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        PrintWriter out = resp.getWriter();

        out.println("execução iniciada em: " + new Date());
        ApplicationContext context = new ClassPathXmlApplicationContext("classpath:app-context.xml");   
        GerenciadorTasks gt = (GerenciadorTasks) context.getBean(SpringNameBeans.GERENCIADOR_TASKS);
        gt.init();
        out.println("execução terminada em: " + new Date());

    }

}

非常感谢您的宝贵时间。

解决方案

--- 按照@Boris 的信息，我稍微修改了我的servlet。我的上下文已经加载，我只需要访问它：

public class AppServlet extends HttpServlet   {

    private static final long serialVersionUID = 7213474106234238692L;

    ApplicationContext applicationContext = null;

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        PrintWriter out = resp.getWriter();

        out.println("execução iniciada em: " + new Date());
         if (applicationContext == null){
                applicationContext = WebApplicationContextUtils.getWebApplicationContext(this.getServletContext());
        }
        GerenciadorTasks gt = (GerenciadorTasks) applicationContext.getBean(SpringNameBeans.GERENCIADOR_TASKS);
        gt.init();
        out.println("execução terminada em: " + new Date());

    }

}
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1 回答 1

2

在您的代码中，您要在每个 GET 方法上创建一个新的应用程序上下文，您应该在 servlet init() 方法中创建您的上下文，或者改用 Web App root contet：

public class AppServlet extends HttpServlet   {

@Autowired
ApplicationContext applicationContext;

@Override
public void init(ServletConfig arg0) throws ServletException {
     WebApplicationContextUtils.getWebApplicationContext(arg0.getServletContext())
        .getAutowireCapableBeanFactory().autowireBean(this);
}

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        PrintWriter out = resp.getWriter();

        out.println("execução iniciada em: " + new Date());

        GerenciadorTasks gt = (GerenciadorTasks) this.applicationContext.getBean(SpringNameBeans.GERENCIADOR_TASKS);
        gt.init();
        out.println("execução terminada em: " + new Date());

    }
}

目前尚不清楚您的 GerenciadorTasks 是否是单例的，所以在我的回答中我使用 getbean() 而不是自动装配。在每个 GET 请求上调用 init() 不太可能是您想要做的。另请注意，根 Web 应用程序上下文已在您的配置中创建

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath*:app-context.xml</param-value>
    </context-param>

    <listener>
      <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
   </listener>

如果您想在 spring 中使用调度，请考虑使用相应的 API。

因此，我认为仅使用调度 api 的根 Web 应用程序上下文是可行的方法。还要看看Spring lifecyle beans。

于 2012-11-29T12:49:15.673 回答