securityfilter.java

一个经典购物车（shoppingcart）实例代码

package com.jpioneer.application.filter;

import java.io.IOException;

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.HttpServletResponse;

public class SecurityFilter implements Filter {
    String blacklist="";
	public void init(FilterConfig arg0) throws ServletException {
		String initpara=arg0.getInitParameter("blacklist");
		if(initpara!=null && !"".equals(initpara)){
			blacklist=initpara;
		}
		
	}

	public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2) throws IOException, ServletException {
		HttpServletRequest request=(HttpServletRequest)arg0;
		HttpServletResponse response=(HttpServletResponse)arg1;
		String authorname=request.getParameter("authorname");
		if(authorname!=null){
			if(authorname.equals(blacklist)){
				response.sendRedirect("/Practice_ServletDB/pages/errors.html");
			}
		}
/*		if(authorname!=null && !"".equals(authorname)){
			if(authorname.equals(blacklist)){
				response.sendRedirect("/Practice_ServletDB/pages/errors.html");
			}
		}*/
		if("nick".equals(blacklist)){
			response.sendRedirect("/Practice_ServletDB/pages/errors.html");
		}
		arg2.doFilter(arg0,arg1);
		
	}

	public void destroy() {
		// TODO Auto-generated method stub
		
	}

}