spring mvc 拦截器

说明：仅供自己学习理解笔记使用

spring mvc 拦截器需要实现HandlerInterceptor接口

 public class UserIsLoginInterceptor implements HandlerInterceptor  {
    @Override
    public boolean preHandle(HttpServletRequest request,
            HttpServletResponse response, Object handler) throws Exception {
        
        System.out.println("Pre-handle");
        
        return false;
    }
    
    @Override
    public void postHandle(HttpServletRequest request,
            HttpServletResponse response, Object handler,
            ModelAndView modelAndView) throws Exception {
        System.out.println("Post-handle");
    }
    
    @Override
    public void afterCompletion(HttpServletRequest request,
            HttpServletResponse response, Object handler, Exception ex)
            throws Exception {
        System.out.println("After completion handle");
    }
}

模拟一个控制器：

@Controller
public class AddUserController {
    @RequestMapping(value = "/user/addUi", method = RequestMethod.GET)
    public String addUi() {
        return "addUser";
    }
}

spring的配置：

<?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:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/mvc 
        http://www.springframework.org/schema/mvc/spring-mvc.xsd">
        
    <context:annotation-config />
    <context:component-scan base-package="net.viralpatel.spring3.controller"/>
    
　　<!--注册spring mvc 拦截器-->
    <mvc:interceptors>
    　　<bean class="com.yjdgis.interceptor.UserIsLoginInterceptor" />
    </mvc:interceptors> 

　　<!--多个拦截器的注册-->
<!--<bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping">
      　　　<property name="interceptors"> 
           　　　　<list>             
　　　　　　　　　　　　 <ref bean="com.yjdgis.interceptor.handlerInterceptor1"/>            
　　　　　　　　　　　　 <ref bean="com.yjdgis.interceptor.handlerInterceptor2"/>          
　　　　　　　　　　</list>      
　　　　　　</property> 
　　 </bean>  -->
   
  <bean id="jspViewResolver"
    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>
</beans>

则拦截器的执行顺序就是此处添加拦截器的顺序；会输出：
HandlerInterceptor1 preHandle 
HandlerInterceptor2 preHandle 
 
HandlerInterceptor2 postHandle
HandlerInterceptor1 postHandle 

HandlerInterceptor2 afterCompletion 
HandlerInterceptor1 afterCompletion

------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 

附加说明：

spring配置文件注册拦截器一

 <mvc:interceptors>
        <mvc:interceptor>
            <mvc:mapping path="/**"/>
            <bean class="com.yjdgis.interceptors.MyInterceptor"></bean>
        </mvc:interceptor>
    </mvc:interceptors>

spring拦截器注册二

bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping">
        <property name="interceptors">
            <list>
                <bean class="com.yjdgis.interceptors.MyInterceptor"></bean>
            </list>
           </property>
    </bean>

在方法二中不可使用<mvc:annotation-driven />。 它默认已经注册了DefaultAnnotationHandlerMapping，AnnotationMethodHandlerAdapter

<!-- 包扫描，注册了各种处理器，<mvc:annotation-driven />也有可能重复注册好多处理器。只有我们都熟悉了，再使用完全自动化吧 -->
<context:component-scan base-package="com.yjdgis"/>

多拦截器注册：

<mvc:interceptors>
        <mvc:interceptor>
            <mvc:mapping path="/**"/>
            <bean class="com.yjdgis.interceptors.MyInterceptor1"></bean>
        </mvc:interceptor>

　　  <mvc:interceptor>
            <mvc:mapping path="/**"/>
            <bean class="com.yjdgis.interceptors.MyInterceptor2"></bean>
         </mvc:interceptor>
    </mvc:interceptors>