4.1简介
Struts2里面有种多方法action，能够让我们在一个类里面处理多个请求，经过我们的配置，能让每个请求对应一个方法。这样，系统就减少了很多类，系统性能也会得到提升。Spring的MultiActionController也是这样的作用。
4.2 开发环境
开发工具:myeclipse8.6.1
数据库:mysql5.5.23
服务器: tomcat6.0.37
框架版本: spring3.2.2
4.3 案例开发步骤
步骤一:在myeclipse8.6中新建web工程springmvc04，拷贝如下包到lib目下：
步骤二:编写web.xml 配置文件，代码如下：
=================================web.xml========================
<?xmlversion="1.0" encoding="UTF-8"?>
<web-appversion="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">
<!-- 配置spring的字符集过滤 -->
<filter>
<filter-name>encode</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<init-param>
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encode</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>
org.springframework.web.servlet.DispatcherServlet
</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
</web-app>
================================================================
步骤三：建立Register.jsp,如下所示:
=========================Register.jsp==============================
<body>
<div id="show">
<h2 align="center">用户注册</h2>
<form action="register.do" method="post">
<table border="1px"cellspacing="0">
<tr><td>请输入用户名:</td><td><input type="text"
name="userName"/></td></tr>
<tr><td>请输入密码:</td><td><input type="password"
name="pwd1"/></td></tr>
<tr><td>请再次输入密码:</td><td><input type="password"
name="pwd2"/></td></tr>
<tr><td>请输入真实姓名:</td><td><input type="text"
name="realName"/></td></tr>
<tr><td>请输入电子邮箱:</td><td><input type="text"
name="email"/></td></tr>
<tr><td>请输入联系电话:</td><td><input type="text"
name="phone"/></td></tr>
<tr><td colspan="2"><input type="submit" value="提交"/>
<input type="reset" value="重置"/></td></tr>
</table>
</form>
</div>
</body>
=====================================================================
步骤四：建立Login.jsp,如下所示:
=========================Login.jsp===================================
<body>
<div id="show">
<form action="login.do"method="post">
<table border="1px" cellpadding="0">
<tr><td>请输入用户名:</td>
<td><input type="text" name="userName"/></td></tr>
<tr><td>请输入密码:</td>
<td><input type="password" name="passWord"/></td></tr>
<tr><td colspan="2">
<input type="submit" value="提交" /></td></tr>
</table>
</form>
</div>
</body>
=====================================================================
步骤五：建立Delete.jsp,如下所示:
=========================Delete.jsp==================================
<body>
<div id="show">
<form action="delete.do"method="post">
<table border="1px" cellpadding="0">
<tr><td>请输入用户名:</td><td>
<input type="text" name="userName"/></td></tr>
<tr><td colspan="2">
<input type="submit" value="提交" /></td></tr>
</table>
</form>
</div>
</body>
=====================================================================
步骤六：建立实体类UserEntity.java,请自行建立，如图所示:
步骤七：在com.wx.controls包下面编写控制器UserControl.java,如下:
===================== UserControl.java===========================
public class UserControl extends MultiActionController{
public ModelAndView register(HttpServletRequestrequest,HttpServletResponse response){
UserEntity theUser=new UserEntity();
theUser.setUserName(request.getParameter("userName"));
theUser.setPwd1(request.getParameter("pwd1"));
theUser.setUserName(request.getParameter("realName"));
theUser.setEmail(request.getParameter("email"));
ModelAndView mov=new ModelAndView("index");
mov.addObject("theUser", theUser);
return mov;
}
public ModelAndView login(HttpServletRequestrequest,HttpServletResponse response){
String userName=request.getParameter("userName");
String passWord=request.getParameter("pwd1");
ModelAndView mov=new ModelAndView("index");
mov.addObject("userName", userName);
mov.addObject("passWord", passWord);
return mov;
}
/*返回字符串的形式*/
public String delete(HttpServletRequestrequest,HttpServletResponse response){
String userName=request.getParameter("userName");
System.out.println("来此了");
request.setAttribute("delUser", userName);
return "index";
}
}
==================================================================
知识讲解：在UserControl中分别定义了三个方法：register() , login() , delete(),是为了对应三个请求—->【/register.do , /login.do , /delete.do】。这三个方法不处理具体业务逻辑，仅仅为了演示绑定三个请求。特别注意第三个方法，视图名不是封装到ModelAndView中，而是直接以字符串的形式返回，特别适合从jsp、servlet开发或从struts2开发转到springmvc开发的童鞋们。
步骤八：在核心配置文件springmvc-servlet.xml里面完善如下配置
======================== springmvc-servlet.xml=======================
<beans>
<bean id="resourceView" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix"value="/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
<bean id="simpleUrlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
<property name="mappings">
<props>
<prop key="/register.do">userControl</prop>
<prop key="/login.do">userControl</prop>
<prop key="/delete.do">userControl</prop>
</props>
</property>
</bean>
<bean id="userControl" class="com.wx.controls.UserControl">
<property name="methodNameResolver" ref="springMethodNameResolver">
</property>
</bean>
<bean id="springMethodNameResolver" class="org.springframework.web.servlet.mvc.multiaction.PropertiesMethodNameResolver">
<property name="mappings">
<props>
<prop key="/register.do">register</prop>
<prop key="/login.do">login</prop>
<prop key="/delete.do">delete</prop>
</props>
</property>
</bean>
</beans>
====================================================================
知识讲解：springMethodNameResolver负责从请求中解析出需要调用的方法名称。Spring本身已经提供了一系列MethodNameResolver的实现，当然也可以编写自己的实现。在这里我们使用了Pro方式来解析，具体表现如下：
<prop key="/register.do">register</prop>当请求为/register.do时,调用register方法
<prop key="/login.do">login</prop>当请求为/login.do时,调用register方法
<prop key="/delete.do">delete</prop>当请求为/delete.do时,调用register方法。
然后通过把springMethodNameResolver解析器注入给UserControl的methodNameResolver(注意划横线处)，这样配置后才完成了一个真正的具有请求转发能力的MultiActionController控制器对象——UserControl。强调：此步骤实质完成了一个
工作：就是为UserControl控制器配置一个方法解析器。【<bean id="simpleUrlMapping"】
表示配置一个映射处理器，把下面三个请求都交给【id=userControl】的bean去处理。
<prop key="/register.do">userControl</prop>
<prop key="/login.do">userControl</prop>
<prop key="/delete.do">userControl</prop>
步骤九：在webroot目录下建立index.jsp
================================index.jsp=======================
<body>
<h2>用户注册:${requestScope.theUser.userName}</h2>
<h2>用户登录:${requestScope.userName}</h2>
<h2>用户删除:${requestScope.delUser}</h2>
</body>
==================================================================
步骤十: 启动tomcat，发布项目，在地址栏分别输入 http://localhost:8080/springmvc04/Register.jsp
http://localhost:8080/springmvc04/Login.jsp
http://localhost:8080/springmvc04/Delete.jsp
进行测试。
