java设置权限过滤器--防止用户未登录访问某些页面

秒速五厘米 2022-03-08 01:04 469阅读 0赞

话不多说，上代码！！！

package com.store.web.filter;
    
    import java.io.IOException;
    import javax.servlet.Filter;
    import javax.servlet.FilterChain;
    import javax.servlet.ServletException;
    import javax.servlet.ServletRequest;
    import javax.servlet.ServletResponse;
    import javax.servlet.annotation.WebFilter;
    import javax.servlet.http.HttpServletRequest;
    
    import com.store.domain.User;
    
    
    @WebFilter(
    		{ "/jsp/order_list.jsp", 
    		  "/jsp/order_info.jsp" ,
    		  "/jsp/cart.jsp"})
    
    /**
      *  权限过滤器，用来阻止用户在没有登录状态下访问某些网页
      *  如果没有登陆，跳转到提示页面，提示用户登录
      *  如果用户已经登录，则放行
     * @author zhujunwei
     * 2019年3月13日 下午8:28:20
     */
    public class PriviledgeFilter implements Filter {
    	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
    		HttpServletRequest httpServletRequest = (HttpServletRequest)request;
    		User user = (User)httpServletRequest.getSession().getAttribute("loginUser");
    		if(null != user) {
    			//已登录，放行
    			chain.doFilter(request, response);
    		} else {
    			//未登录，提示登录
    			httpServletRequest.setAttribute("msg", "您还没有登录，请登录后访问");
    			httpServletRequest.getRequestDispatcher("/jsp/info.jsp").forward(request, response);
    		}
    	}
    }