解决方案

Question

几个月前，如果找到数据库中的某些条件，我每天晚上都会运行一个简单的应用程序来向我的用户发送电子邮件。我用Spring 3.1.0和Quartz 1.8.5来完成这个任务;到目前为止，非常好。

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运行URL。

我添加了一个servlet并且工作正常：每当有人调用URL时，应用就会运行。

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，如果所述servlet被调用了n次，那么当Quartz触发我的工作时，我的应用程序将发送n + 1个重复的电子邮件，而不仅仅是1.

我想了解为什么会发生这种情况以及如何解决这个问题。你能帮帮我吗？

以下是我提问的相关文件。

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时发生的日志文件摘录：

<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**

的web.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>

APP-scheduler.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());

    }

}

非常感谢你的时间。

解决方案

---关注@Boris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());

    }

}

Answer 1

在你的代码中，你要在每个GET方法上创建一个新的应用程序上下文，你应该在servlet init（）方法中创建你的上下文，或者改为使用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());

    }
}

目前尚不清楚你的GerenciadorTasks是否是单身人士，所以在我的回答中我使用了getbean（）而不是自动装配。 在每个GET请求上调用init（）是不太可能的，你想做什么。另请注意，{/ 3}}已在您的配置中使用

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>

如果您想在春季使用计划，请考虑使用root web app context。

所以我认为仅使用根网络应用程序上下文与调度api是可行的方法。另请查看the respective API。

为什么每次访问servlet时我的Spring应用程序上下文都会重新加载？

解决方案

1 个答案: