SpringMvc中的拦截器

1、创建自定义拦截器 

package com.bdqn.interceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
import com.bdqn.pojo.User;
import com.bdqn.tools.Constants;

public class SysInterceptor extends HandlerInterceptorAdapter{
	
	public boolean preHandle(HttpServletRequest request,
		                HttpServletResponse response,
		                Object handler) throws Exception{
		HttpSession session=request.getSession();
		User user=(User)session.getAttribute(Constants.USER_SESSION);

		if(null==user){ //如果session中没有用户信息，则重定向到401页面

			response.sendRedirect(request.getContextPath()+"/401.jsp");
			return false;
		}
	        return true;
	}
	
}

 2、在springmvc-servlet.xml中配置刚才创建的拦截器

<!-- 配置自定义拦截器interceptors -->
	<mvc:interceptors>
		<mvc:interceptor>
			<mvc:mapping path="/sys/**"/>
			<bean class="com.bdqn.interceptor.SysInterceptor"></bean>
		</mvc:interceptor>
	</mvc:interceptors>

3、演示效果