servlet过滤器过滤所有，只放行登录相关模块最近做项目用到了servlet的过滤器，发现如果仅仅只是从web.xml文
servlet过滤器过滤所有，只放行登录相关模块
最近做项目用到了servlet的过滤器，发现如果仅仅只是从web.xml文件上配置不够灵活，很难达到项目要求，用户体验度也不好，故在配置文件中加上过滤应用全局：
package com.speed.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;/* * 安全过滤器修正v1版本 * 功能：只允许登录过的用户访问资源 */public class LimitFilter implements Filter {FilterConfig filterconfig;public void init(FilterConfig arg0) throws ServletException {filterconfig = arg0;}public void doFilter(ServletRequest arg0, ServletResponse arg1,FilterChain arg2) throws IOException, ServletException {HttpServletRequest request = (HttpServletRequest) arg0;HttpServletResponse response = (HttpServletResponse) arg1;String request_uri = request.getRequestURI(); String ctx_path = request.getContextPath(); if(request_uri.substring(ctx_path.length()).equals("/loginFailure.jsp")|| request_uri.substring(ctx_path.length()).equals("/")|| request_uri.substring(ctx_path.length()).equals("/validateCode.action")|| request_uri.substring(ctx_path.length()).equals("/loginByForm.jsp")|| request_uri.substring(ctx_path.length()).equals("/userMgr.action")) {System.out.println("------filter输出------安全验证登录通过uri："+request_uri); arg2.doFilter(arg0, arg1);}else if(request_uri.substring(ctx_path.length()).equals("/images/login2.jpg")||request_uri.substring(ctx_path.length()).equals("/images/enter.gif")||request_uri.substring(ctx_path.length()).equals("/images/reset.gif")||request_uri.substring(ctx_path.length()).equals("/images/shutdown.jpg")){arg2.doFilter(arg0, arg1);}else{if (request.getSession().getAttribute("USER_INFO") == null) {response.setCharacterEncoding("utf-8");System.out.println(ctx_path+"/loginFailure.jsp");response.sendRedirect(ctx_path+"/loginFailure.jsp");return;} else {arg2.doFilter(arg0, arg1);}}}public void destroy() { }}