HTTP Status 404 - Servlet dispatcherServlet is not available

我把代码贴上来，麻烦大家帮我看看这个错误是为什么？web.xml<?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">
<servlet>
<servlet-name>dispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!--初始化参数-->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/dispatcherServlet-servlet.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>  dispatcherServlet-servlet.xml<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<!--定义映射-->
    <bean id="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
        <property name="mappings">
            <props>
               <prop key="user.do">userFormController</prop>
            </props>
        </property>
</bean>
<!--定义视图-->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="viewClass">
            <value>org.springframework.web.servlet.view.InternalResourceView</value>
        </property> 
</bean>
<bean id="userFormController" class="com.action.userFormController">
        <property name="commandClass">
            <value>com.model.User</value>
        </property>
        <property name="ViewPage">
            <value>/view.jsp</value>
        </property>
    </bean>
</beans>submit.jsp<%@page contentType="text/html;charset=GBK"%>
<html> 
<head><title>练习使用SimpleFormController</title></head> 
<body> 
    <form name="HelloWorld" action="test/user.do" method="post"> 
        请输入要提交的内容：<input type="text" name="username" value=""/><br> 
        <input type="text" name="password" value=""/>
        <input type="submit" value="提交"/> 
    </form> 
</body> 
</html>userFormController.javapackage com.action;import java.util.HashMap;
import java.util.Map;import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.SimpleFormController;import com.model.User;public class userFormController extends SimpleFormController{ private String ViewPage;

public ModelAndView OnSubmit(Object command){

User user = (User)command;
Map model = new HashMap();
model.put("user",user);
return new ModelAndView(getViewPage(),model);
} public String getViewPage() {
return ViewPage;
} public void setViewPage(String viewPage) {
this.ViewPage = viewPage;
}
}