UserFilter.java ~~~ package zyw.filter; import zyw.bean.User; import javax.servlet.*; import javax.servlet.annotation.WebFilter; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import java.io.IOException; @WebFilter(filterName = "UserFilter",urlPatterns = "/category") public class UserFilter implements Filter { public void destroy() { } public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException { req.setCharacterEncoding("utf-8"); resp.setContentType("text/html;charset=utf-8"); // 1 获取serssion 校验用户信息 HttpServletRequest request= (HttpServletRequest) req; HttpServletResponse response= (HttpServletResponse) resp; HttpSession session = request.getSession(); User user = (User) session.getAttribute("user"); // 2 判断user信息是否为空 ，空则跳转登录界面 if (user==null) { response.sendRedirect(request.getContextPath()+"/login.jsp"); return; } // 3 user不为空 放行 chain.doFilter(req, resp); } public void init(FilterConfig config) throws ServletException { } } ~~~ UserServlet.java ~~~ package zyw.web; import org.apache.commons.beanutils.BeanUtils; import zyw.bean.User; import zyw.service.UserService; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.Cookie; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.lang.reflect.InvocationTargetException; import java.sql.SQLException; import java.util.Map; @WebServlet(name = "UserServlet",urlPatterns = "/user") public class UserServlet extends BaseServlet { /* protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request,response); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String method = request.getParameter("method"); if ("login".equals(method)){ login(request,response); }else if("register".equals(method)){ register(request,response); } }*/ public void login(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String name = request.getParameter("name"); String password = request.getParameter("password"); UserService userService=new UserService(); User user=null; try { //调用service中登录方法 user = userService.login(name, password); } catch (SQLException e) { e.printStackTrace(); } if (user!=null){ //登录成功后我们再获取是否保存密码的信息，如果失败了保存密码就没有意义了 String remember = request.getParameter("remember"); if (remember.equals("yes")){ // 将用户名和密码加入到cookie中 Cookie nameCookie = new Cookie("name", name); Cookie passwordCookie = new Cookie("password", password); //设置cookie的有效期 防止销毁 nameCookie.setMaxAge(60*10);//10分钟 passwordCookie.setMaxAge(60*10); //将cookie发送给客户端保存 response.addCookie(nameCookie); response.addCookie(passwordCookie); } //权限控制登录 request.getSession().setAttribute("user",user); //登录成功跳转生鲜种类列表界面 response.sendRedirect(request.getContextPath()+"/category?method=queryCategoryList&currentCount=0&currentPage=0"); }else { //登录失败提示 response.setContentType("text/html;charset=utf-8"); response.getWriter().write("用户登录失败"); } } public void register(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String name = request.getParameter("name"); String id = request.getParameter("id"); String password = request.getParameter("password"); String email = request.getParameter("email"); User user=new User(); Map<String,String[]> stringMap =request.getParameterMap(); try { //分别将属性设置到对象中 // BeanUtils.setProperty(user,name,name); //将属性的map集合封装到对象中 BeanUtils.populate(user,stringMap); } catch (IllegalAccessException e) { e.printStackTrace(); } catch (InvocationTargetException e) { e.printStackTrace(); } UserService userService=new UserService(); // boolean register = userService.register(user); boolean register = userService.register(user); if (register) { response.sendRedirect(request.getContextPath()+"login.jsp"); }else { response.setContentType("text/html;charset=utf-8"); response.getWriter().write("注册失败"); } } } ~~~ 主要在UserServlet.java中添加 ~~~ //权限控制登录 request.getSession().setAttribute("user",user); ~~~ 本项目源码，下载密码：higj ，[点击下载](https://pan.baidu.com/s/1sD701efqdonZ71efrMO2JQ)