JAVA filter 过滤器

package com.suypower.NJESIS.systemManage;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class RequestFilter implements Filter{
	public void init(FilterConfig filterConfig) throws ServletException{
		System.out.println("---RequestFilter-inited---");
	}

	public void doFilter(ServletRequest request,ServletResponse response,FilterChain fc) throws ServletException,IOException{
		HttpServletRequest req=(HttpServletRequest)request;
		HttpServletResponse res=(HttpServletResponse)response;
		req.setCharacterEncoding("gbk");
		String uri=req.getRequestURI();

		// 未登录时访问项目中的任何路径,都跳转到登录页面
		if( req.getSession().getAttribute("userbean")!=null ||
				uri.endsWith("/login.jsp") || uri.endsWith("/login") ||
				uri.endsWith("/login_go.jsp") || uri.endsWith("/login.css") ||
				uri.endsWith("/login.gif") || uri.endsWith("/input.gif") ||
				uri.endsWith("/botton-qued.gif") || uri.endsWith("/botton-qux.gif")|| uri.endsWith("//login_sso.jsp")
				){
			fc.doFilter(req, res);
		}
		else{
			res.sendRedirect(req.getContextPath()+"/NJESIS/login.jsp");
		}
	}

	public void destroy(){
		System.out.println("---RequestFilter-destroyed---");
	}
}