基于java开发的学生成绩管理系统源码

package mywebapp; import java.io.IOException; import java.util.ArrayList; import java.util.List; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class userLoginCheckFilter implements Filter { public static final String login_page = "/index.jsp"; public void destroy(){ } public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain)throws ServletException, IOException { // servletRequest.setCharacterEncoding("UTF-8"); //servletResponse.setCharacterEncoding("UTF-8"); HttpServletRequest request = (HttpServletRequest)servletRequest; HttpServletResponse response = (HttpServletResponse)servletResponse; String currentURL = request.getRequestURI(); String ctxPath = request.getContextPath(); //除掉项目名称时访问页面当前路径 String targetURL = currentURL.substring(ctxPath.length()); System.out.println(targetURL); List<String>info = new ArrayList<String>(); HttpSession session = request.getSession(false); //对当前页面进行判断，如果当前页面不为登录页面 if(!(("/index.jsp".equals(targetURL)) || ("/selectLogin.jsp".equals(targetURL)) || ("/studentLogin.jsp".equals(targetURL)))){ //System.out.println("1"+targetURL+"ctxPath:"+ctxPath+"currentURL:"+currentURL); //在不为登陆页面时，再进行判断，如果不是登陆页面也没有session则跳转到登录页面， if(session == null || session.getAttribute("admin") == null){ info.add("You are not logged in!"); request.setAttribute("info",info); request.getRequestDispatcher(login_page).forward(request,response); return; }else{ //这里表示正确，会去寻找下一个链，如果不存在，则进行正常的页面跳转 filterChain.doFilter(request, response); return; } }else{ //这里表示如果当前页面是登陆页面，跳转到登陆页面 try{ filterChain.doFilter(request, response); }catch (Exception e){ throw e; } return; } } public void init(FilterConfig filterConfig)throws ServletException{ } }