loginfilter.java

一套购物车项目。电子商务系统。实现了前台和后台的业务逻辑。

package com.softfz.jn0708.filter;

import java.io.IOException;
import java.util.Enumeration;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

/**
 * 
 * 登录过滤器
 * @author student
 *
 */
public class LoginFilter implements Filter{

	public void init(FilterConfig arg0) throws ServletException {
		
		
	}

	public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
		HttpServletRequest request = (HttpServletRequest)req;
		HttpSession session = request.getSession();
			
		if(session.getAttribute("uname")!=null){
			
			chain.doFilter(req,res);
		}else{
			
				String uri = request.getRequestURI();
				String params ="";
				Enumeration urlParams=request.getParameterNames();
				while(urlParams.hasMoreElements()){
					String paramName = (String)urlParams.nextElement();
					String paramValue = request.getParameter(paramName);
					params += paramName+"="+paramValue +"&"; 
				}
				if(!params.equals("")){				
					params = params.substring(0,params.length()-1);					
				}
				uri = uri + "?"+params;
				request.setAttribute("uri",uri);
				request.getRequestDispatcher("/shop/login.jsp").forward(req,res);
				
			
		}		

	}
	
	public void destroy() {
	
	}

}