6.SpringMVC注解启用

SpringMVC注解可以帮助我们快速地注入 属性和参数 提高开发效率。

由于

1. 有相当一部分人讨厌xml配置方式

2. 注解可以覆盖 xml则不能

3. 使用注解比xml规范化，因为很多注解都是java的规范的范畴,当你使用象jndi,或jpa这样规范化统一框架时不需要更改注解 ,xml则不行

缺点：

不利于维护，springmvc xml配置文件可以看清所有的mvc架构，易于维护，可读性强。

运行的错误：

严重: StandardWrapper.Throwable
java.lang.NoClassDefFoundError: javax/portlet/PortletResponse

上述问题一般就是jar包引错或者是

解决方案：

你bean里是不是引入了一个InternalResourceViewResolver类，这个类的包是web.servlet,不是web.portlet;
<beans:bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">

引入jar包

1.web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
    xmlns="http://java.sun.com/xml/ns/javaee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
    http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
    <servlet>
    <!--基础配置有springMVC配置的servlet路径-->
    <servlet-name>SpringMVC</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <!--如果需要加载其他地方的多个springMVC配置文件-->
           <init-param>
               <param-name>contextConfigLocation</param-name>
               <param-value>classpath*:config/SpringMVCAnnotation-servlet.xml</param-value>
               <!--classpath*代表在src下寻找config文件夹再在其中寻找以-servlet.xml文件结尾的文件-->
           </init-param>
           <!--配置加载顺序的，数字越低优先级越高-->
           <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>SpringMVC</servlet-name>
        <url-pattern>/</url-pattern><!-- 拦截所有请求 -->
    </servlet-mapping>
</web-app>

2.SpringMVCAnnotation-servlet.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:p="http://www.springframework.org/schema/p"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="     
           http://www.springframework.org/schema/beans     
           http://www.springframework.org/schema/beans/spring-beans-3.0.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">
<!-- 注解开始 -->
<!--spring启动时的注解扫描包-->
    <context:component-scan base-package="annotation"></context:component-scan>
<!-- 两个bean的作用是根据url找类，根据类去找方法-->
    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" />  
    <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping"></bean>
    <!-- 静态资源访问 -->
    <mvc:resources location="/img/" mapping="/img/**" />
    <mvc:resources location="/js/" mapping="/js/**" />
    <!--以上两句就是设置spring的拦截器不对img文件夹与js文件夹的文件进行拦截-->
    


    <!-- 视图解析器 -->
    <bean id="viewResolver"
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/"></property> <!-- 前缀 -->
        <property name="suffix" value=".jsp"></property> <!-- 后缀 -->
    </bean>
</beans> 

3.UserController.java

package annotation;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;
@Controller
public class UserController {
    //value指的是浏览器要请求的地址，method指的是请求的方式
    @RequestMapping(value="/user/addUser",method=RequestMethod.POST)
    public ModelAndView addUser(){
        String result ="---1.this is addUser---";
        return new ModelAndView("/annotation","result",result);
    }
    @RequestMapping(value="/user/delUser",method=RequestMethod.GET)
    public ModelAndView delUser(){
        String result ="---2.this is delUser---";
        return new ModelAndView("/annotation","result",result);
    }
    @RequestMapping(value="/user/toUser",method=RequestMethod.GET)
    public ModelAndView toUser(){
        String result ="---3.this is toUser---";
        return new ModelAndView("/touser","result",result);
    }
}
/*此处请注意，@Controller的使用。@RequestMapping(value="/user/addUser",method=RequestMethod.POST)中的value表示跳转路径，method表示通过哪种方式调用这个方法*/

4.annotation.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
  </head>
  
  <body>
    <h1>SpringMVC注解1 <h1/><br>
    ${result}
  </body>
</html>

5.touser.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>  
<%  
String path = request.getContextPath();  
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";  
%>  
  
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">  
<html>  
  <head>  
    <base href="<%=basePath%>">  
      
    <title>My JSP 'index.jsp' starting page</title>  
    <meta http-equiv="pragma" content="no-cache">  
    <meta http-equiv="cache-control" content="no-cache">  
    <meta http-equiv="expires" content="0">      
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">  
    <meta http-equiv="description" content="This is my page">  
    <!--  
    <link rel="stylesheet" type="text/css" href="styles.css">  
    -->  
  </head>  
    
  <body>  
    <form action="/springMVC4/user/addUser" method="post">  
    <h1>SpringMVC注解</h1>   
    <br>  
    ${result }  
    <input type="submit"  value="post请求">  
    </form>  
  </body>  
</html>