springmvc No mapping found for HTTP request with URI in Dispatc

项目是使用spring MVC

（1）在浏览器中访问，后台总报错：

No mapping found for HTTP request with URI [/exam3/welcome] in DispatcherServlet with name 'spring2'

 查了好半天，才发现是controller 没有扫描到。

我是使用的注解。

spring mvc配置文件如下：

<?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"
	xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
            http://www.springframework.org/schema/context
           http://www.springframework.org/schema/context/spring-context-3.2.xsd
           http://www.springframework.org/schema/aop
           http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
           http://www.springframework.org/schema/tx 
           http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
           http://www.springframework.org/schema/mvc 
           http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd"
           >

	<!-- HandlerMapping -->
	<bean
		class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping" />

	<!-- HandlerAdapter -->
	<bean
		class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter" />
	<!-- ViewResolver -->
	<bean
		class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="viewClass"
			value="org.springframework.web.servlet.view.JstlView" />
		<property name="prefix" value="/WEB-INF/jsp/" />
		<property name="suffix" value=".jsp" />
	</bean>
<mvc:annotation-driven />
<!-- 处理器 -->  
<!-- <bean name="/hello" class="com.mvc.jn.controller.HelloWorldController"/> -->
<context:component-scan base-package="com"/>
</beans>

 controller 的目录结构如下：

 

 

（2）这个问题解决之后，又报错：

No mapping found for HTTP request with URI [/exam3/WEB-INF/jsp/welcome.jsp] in DispatcherServlet with name 'spring2'

结果发现是web.xml配置得有问题，下面是有问题的：

<servlet>
		<servlet-name>spring2</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<load-on-startup>1</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>spring2</servlet-name>
		<url-pattern>/*</url-pattern>
	</servlet-mapping>

 解决方法：把url-pattern 由/* 改为/