spring2.0里怎么指定org.springframework.web.context.request.RequestContextListener

Question

按照书上的说法，我tomcat是6.0,支持web-app2.4,按照如下方式配置web.xml应该是可以的：<?xml version="1.0" encoding="UTF-8"?>
<web-app 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">
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</context-param>
<listener>
<listener-class>
org.springframework.web.context.request.RequestContextListener
</listener-class>
</listener>
</web-app>applicationContext.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"
xmlns:util="http://www.springframework.org/schema/util"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans 
         http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
         http://www.springframework.org/schema/util 
http://www.springframework.org/schema/util/spring-util-2.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd
         ">
<bean id="propertyConfigurer"
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location" value="classpath:jdbc.properties" />
</bean>
<bean id="dataSource"
class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close">
<property name="driverClassName"
value="${jdbc.driverClassName}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
</bean>
<bean id="jdbcTemplate"
class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="dataSource" />
</bean>

<bean id="forumDao" 
class="com.baobaotao.dao.jdbc.ForumJdbcDao" >
       <property name="jdbcTemplate" ref="jdbcTemplate"/>
    </bean>
    
    <bean id="postDao" class="com.baobaotao.dao.jdbc.PostJdbcDao">
     <property name="jdbcTemplate" ref="jdbcTemplate"></property>
    </bean>
    
    <bean id="topicDao" class="com.baobaotao.dao.jdbc.TopicJdbcDao">
     <property name="jdbcTemplate" ref="jdbcTemplate"></property>
    </bean>
    
   <bean id="template" class="org.springframework.transaction.support.TransactionTemplate">
       <property name="transactionManager" ref="txManager"></property>
   </bean>
   
   <bean id="forumService1" class="com.baobaotao.service.ForumService1">
       <property name="forumDao" ref="forumDao"/>
       <property name="template" ref="template"/>
    </bean> <tx:annotation-driven transaction-manager="txManager"/>
<!-- a PlatformTransactionManager is still required -->
<bean id="txManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<!-- (this dependency is defined somewhere else) -->
<property name="dataSource" ref="dataSource" />
</bean>

<bean id="userService" class="com.baobaotao.service.UserService"/>
    <bean id="forumService" class="com.baobaotao.service.ForumService">
       <property name="userService" ref="userService"/>
    </bean>
    
    <bean id="bbtForum" class="com.baobaotao.service.impl.BbtForumImpl" autowire="byName">
    </bean>
</beans>
test.jsp:<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<jsp:directive.page import="com.baobaotao.service.BbtForum"/>
<jsp:directive.page import="org.springframework.context.ApplicationContext"/>
<jsp:directive.page import="org.springframework.web.context.support.WebApplicationContextUtils"/>
<jsp:directive.page import="com.baobaotao.domain.Topic"/>
<jsp:directive.page import="com.baobaotao.domain.Post"/>
<%
        ApplicationContext ctx = WebApplicationContextUtils.getWebApplicationContext(application);
        BbtForum bbtForum = (BbtForum)ctx.getBean("bbtForum");//这行获得了null
     System.out.println("begin........");
     Topic topic = new Topic();
     topic.setTopicTitle("Title:jta-tomcat");
     Post post = new Post();
     post.setPostText("post content:jta-tomcat");
     topic.setPost(post);
     bbtForum.addTopic(topic);
     System.out.println("end........");
     System.out.println(ctx.getBean("bbtForum")==ctx.getBean("bbtForum"));
 %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body></body>
</html>访问test.jsp的时候就抛出空指针异常了，如果用传统的org.springframework.web.context.ContextLoaderListener则运行正常。

Answer 1

RequestContextListener与ContextLoaderListener好像有点区别吧，至少对于作用域上是不同的，在Spring2.0中除了以前的Singleton和Prototype外又加入了三个新的web作用域，分别为request、session和global session，你去查一下Spring官方手册，好像里面是这样写的：当使用了Spring's DispatcherServlet以外的Servlet 2.4及以上的Web容器时（如使用JSF或Struts），你需要在Web应用的'web.xml'文件中增加 javax.servlet.ServletRequestListener 定义