servlet 过滤器及登录页面

1---------------------------- 登录过滤类loginFilter ------------------------------------------ package spell; 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.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class loginFilter extends HttpServlet implements Filter { private FilterConfig filterConfig; //Handle the passed-in FilterConfig public void init(FilterConfig filterConfig) throws ServletException { this.filterConfig = filterConfig; } //Process the request/response pair public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) { try { HttpServletRequest req=(HttpServletRequest)request; HttpServletResponse rsp=(HttpServletResponse)response; HttpSession session=req.getSession(true); String userName=(String)session.getAttribute("userName"); if(userName!=null) {//验证通过 filterChain.doFilter(request, response); } else {//验证不通过,取得设置的跳转页面参数 String noLogin=filterConfig.getInitParameter("noLogin"); rsp.sendRedirect(noLogin); } } catch (Exception sx) { filterConfig.getServletContext().log(sx.getMessage()); } } //Clean up resources public void destroy() { } protected void doGet(HttpServletRequest arg0, HttpServletResponse arg1) throws ServletException, IOException { // TODO Auto-generated method stub super.doGet(arg0, arg1); } protected void doPost(HttpServletRequest arg0, HttpServletResponse arg1) throws ServletException, IOException { // TODO Auto-generated method stub super.doPost(arg0, arg1); } } web.xml配置 ---------------------------- <filter> <filter-name>loginFilter</filter-name> <filter-class>spell.loginFilter</filter-class> <!--loginFilter对应的类名--> <init-param> <param-name>noLogin</param-name> <param-value>../strutsHtml.jsp</param-value> <!--没有登录跳转的页面--> </init-param> </filter> <filter-mapping> <filter-name>loginFilter</filter-name> <!--选择loginFilter来验证登录--> <url-pattern>/member/*</url-pattern> <!--配置member下的文件要求权限判断--> </filter-mapping> 2----------------------------- servlet登陆拦截器 2012-07-26 11:25:03| 分类： 默认分类 |举报|字号 订阅 实现Servlet.Filter接口 public class AdminLoginFilter implements Filter 新建一个实现filter接口的类,实现dofilter方法，在dofilter方法里面写一个判读，比如如果用户名密码为空，则返回到登录页面 public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2) throws IOException, ServletException { HttpServletResponse response = (HttpServletResponse) arg1; HttpServletRequest request=(HttpServletRequest)arg0; HttpSession session = request.getSession(true); String username = (String) session.getAttribute("username");// String url=request.getRequestURI(); if(username==null || username.equals("")) { //判断获取的路径不为空且不是访问登录页面或执行登录操作时跳转 if(url!=null && !url.equals("") && ( url.indexOf("Login")<0 && url.indexOf("login")<0 )) { response.sendRedirect("login.jsp"); return ; } } //已通过验证，用户访问继续 arg2.doFilter(arg0, arg1); } web.xml配置过滤器 <filter> <filter-name>AdminLoginFilter</filter-name> <filter-class>com.vnb.servlet.AdminLoginFilter</filter-class> </filter> <!-- 配置多个映射，哪些请求执行过滤器 --> <filter-mapping> <filter-name>AdminLoginFilter</filter-name> <url-pattern>/web-inf/*</url-pattern> </filter-mapping> <filter-mapping> <filter-name>AdminLoginFilter</filter-name> <url-pattern>*.jsp</url-pattern> </filter-mapping> 3---------------------------------- public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2) throws IOException, ServletException { HttpServletResponse response = (HttpServletResponse) arg1; HttpServletRequest request=(HttpServletRequest)arg0; HttpSession session = request.getSession(true); String username = (String) session.getAttribute("username");// String url=request.getRequestURI(); if(username==null || username.equals("")) { //判断获取的路径不为空且不是访问登录页面或执行登录操作时跳转 if(url!=null && !url.equals("") && ( url.indexOf("Login")<0 && url.indexOf("login")<0 )) { response.sendRedirect("login.jsp"); return ; } } //已通过验证，用户访问继续 arg2.doFilter(arg0, arg1); } web.xml配置过滤器 <filter> <filter-name>AdminLoginFilter</filter-name> <filter-class>com.vnb.servlet.AdminLoginFilter</filter-class> </filter> <!-- 配置多个映射，哪些请求执行过滤器 --> <filter-mapping> <filter-name>AdminLoginFilter</filter-name> <url-pattern>/web-inf/*</url-pattern> </filter-mapping> <filter-mapping> <filter-name>AdminLoginFilter</filter-name> <url-pattern>*.jsp</url-pattern> </filter-mapping> 4--------------------------- 用filter结合session 例如： public class CheckStuLoginFilter implements Filter { public void destroy() { // TODO Auto-generated method stub } public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { HttpServletResponse resp = (HttpServletResponse) response; HttpServletRequest req = (HttpServletRequest) request; HttpSession session = req.getSession(); Stuinfo stuinfo = (Stuinfo) session.getAttribute("stuinfo"); String requestURI = req.getRequestURI().substring( req.getRequestURI().indexOf("/", 1), req.getRequestURI().length()); if (!requestURI.equals("/index.jsp")) { if (stuinfo == null) { resp.sendRedirect(req.getContextPath() + "/index.jsp"); return; } } chain.doFilter(request, response); } public void init(FilterConfig arg0) throws ServletException { // TODO Auto-generated method stub } }