dwr学习 之 一、dwr+spring的简单集成

1. 环境搭建

我采用的环境为SpringMVC + myBatis + mySql + maven；

关于使用Eclipse构建Maven的SpringMVC项目，请参考： http://limingnihao.iteye.com/blog/830409.

关于mybatis，请参考：http://limingnihao.iteye.com/blog/781671

1.1 web.xml

在配置好SpringMVC的环境之下，需要在web.xml中给Spring的dispatcher在添加一个dwr的servlet-mapping。

Xml代码:

     <!-- spring -->
     <servlet>
         <servlet-name>springDispatcher</servlet-name>
         <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
         <init-param>
             <param-name>contextConfigLocation</param-name>
             <param-value>/WEB-INF/dispatcher-servlet.xml</param-value>
         </init-param>
         <load-on-startup>1</load-on-startup>
     </servlet>
     <servlet-mapping>
         <servlet-name>springDispatcher</servlet-name>
         <url-pattern>*.do</url-pattern>
     </servlet-mapping>  

     <!-- dwr设置 -->
     <servlet-mapping>
         <servlet-name>springDispatcher</servlet-name>
         <url-pattern>/dwr/*</url-pattern>
     </servlet-mapping>  

1.2 Spring配置文件

添加dwr的namespace、dwr的controller、注解扫描等标签。给出配置文件全部内容如下：

Xml代码:

 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
     xmlns:aop="http://www.springframework.org/schema/aop"
     xmlns:context="http://www.springframework.org/schema/context"
     xmlns:mvc="http://www.springframework.org/schema/mvc"
     xmlns:tx="http://www.springframework.org/schema/tx"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xmlns:dwr="http://www.directwebremoting.org/schema/spring-dwr"
     xsi:schemaLocation="http://www.springframework.org/schema/aop
         http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
         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
         http://www.springframework.org/schema/mvc
         http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
         http://www.springframework.org/schema/tx
         http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
         http://www.directwebremoting.org/schema/spring-dwr
         http://www.directwebremoting.org/schema/spring-dwr-3.0.xsd">  

     <aop:aspectj-autoproxy />
     <mvc:annotation-driven />
     <context:component-scan base-package="liming.student.manager" />  

     <!-- 导入属性配置文件 -->
     <context:property-placeholder location="classpath:mysql.properties" />  

     <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
         <property name="prefix" value="/WEB-INF/views/" />
         <property name="suffix" value=".jsp" />
     </bean>  

     <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
         <property name="driverClassName" value="${jdbc.driverClassName}" />
         <property name="url" value="${jdbc.url}" />
         <property name="username" value="${username}" />
         <property name="password" value="${password}" />
     </bean>  

     <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
         <property name="dataSource" ref="dataSource" />
     </bean>  

     <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
         <property name="configLocation" value="classpath:mybatis-config.xml" />
         <property name="dataSource" ref="dataSource" />
     </bean>  

     <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
         <property name="annotationClass" value="org.springframework.stereotype.Repository" />
         <property name="basePackage" value="liming.student.manager" />
         <property name="sqlSessionFactory" ref="sqlSessionFactory" />
     </bean>  

     <!-- DWR配置 -->
     <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping">
         <property name="order" value="1" />
     </bean>
     <bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping">
         <property name="order" value="2" />
     </bean>
     <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" />
     <bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter" />
     <bean class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
         <property name="order" value="3" />
         <property value="true" name="alwaysUseFullPath"></property>
         <property name="mappings">
             <props>
                 <prop key="/dwr/**">dwrController</prop>
             </props>
         </property>
     </bean>  

     <dwr:controller id="dwrController" debug="true">
         <dwr:config-param name="allowScriptTagRemoting" value="true" />
         <dwr:config-param name="crossDomainSessionSecurity" value="false" />
     </dwr:controller>
     <dwr:configuration></dwr:configuration>
     <dwr:annotation-config />
     <dwr:annotation-scan scanRemoteProxy="true" scanDataTransferObject="true" base-package="liming.student.manager" />  

 </beans> 

2. 配置文件解说

2.1 controller

添加dwr的dwr:controller标签，debug为true时，可以访问/dwr/index.html的测试页面。还可以可以设置一些参数的值：

Xml代码:

 <dwr:controller id="dwrController" debug="true">
     <dwr:config-param name="allowScriptTagRemoting" value="true" />
     <dwr:config-param name="crossDomainSessionSecurity" value="false" />
 </dwr:controller> 

controller常用配置：

参数名称	默认值	说明
jsonpEnabled	false	Set to true to enable DWR's JSONP remoting.
allowGetForSafariButMakeForgeryEasier	false	Set to true to make DWR work in Safari 1.x (where a bug drops the bodies from POST requests). POST requests are slightly harder to forge, so enabling this reduces security slightly.
crossDomainSessionSecurity	true	Set to false to enable requests from other domains. Note that enabling this can be a significant security risk. See the Wikipedia notes on CSRF for more. Do not set this to false without understanding the consequences.
allowScriptTagRemoting	true	Set to true to enable Script Tag remoting. Note that enabling this can be a significant security risk. See the Wikipedia notes on CSRF for more. Do not set this to false without understanding the consequences. There are some cases where you will need to enable Script Tag remoting, but want to leave crossDomainSessionSecurity in place - particularly when you have an http based web page, and an https based DWR service.
debug	false	Set to true to enable the debug/test pages.
scriptSessionTimeout	1800000 (30 mins)	How quickly do scriptSessions timeout?
maxCallCount	20	What is the maximum number of calls that can be done in a single batch. (Helps prevent DoS attacks).

2.2 url-mapping

在Springmvc中，每个url都需要一个controller的映射器(RequestMapping)，需要使用<dwr:url-mapping />标签进行声明，这样才可以访问/engine.js, /interface.js, /call/**, /interface/**路径。但是带来的不管是测试页(/dwe/index.html)将不能访问。解决办法是，声明一个SimpleUrlHandlerMapping的bean指定dwr的请求路径：