springmvc拦截器和概念，配置！！！

用于拦截请求，过滤后再拦截

实现HandlerInterceptor接口

配置拦截器

package cn.zys.lanjieqi;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

public class MyZhujieqi implements HandlerInterceptor{
    //在请求处理方法之前执行
    //如果返回true 执行下一个拦截器
    //如果返回false 就不执行下一个
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
            throws Exception {
        // TODO Auto-generated method stub
        System.out.println("处理前~~");
        return true;
    }

    //在请求处理方法之后执行
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
            ModelAndView modelAndView) throws Exception {
        // TODO Auto-generated method stub
        System.out.println("处理后~~");
        HandlerInterceptor.super.postHandle(request, response, handler, modelAndView);
    }

    //DispatcherServlet 处理后执行    --适合做一些清理工作
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
            throws Exception {
        // TODO Auto-generated method stub
        HandlerInterceptor.super.afterCompletion(request, response, handler, ex);
    }

}

配置mvc.xml

<!-- 拦截器的配置 -->
    <mvc:interceptors>
    <!-- 配置一个拦截器 -->
        <mvc:interceptor>
        <!-- /**此路径下的所有子路径 -->
            <mvc:mapping path="/**"/>
            <bean class="cn.zys.lanjieqi.MyZhujieqi"></bean>
        </mvc:interceptor>
    </mvc:interceptors>