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.HttpServlet; 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 HttpServlet { 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); } } protected 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 { //調用service中登錄方法 user = userService.login(name, password); } catch (SQLException e) { e.printStackTrace(); } if (user!=null){ //登錄成功后我們再獲取是否保存密碼的信息，如果失敗了保存密碼就沒有意義了 String remember = request.getParameter("remember"); if (remember.equals("yes")){ // 將用戶名和密碼加入到cookie中 Cookie nameCookie = new Cookie("name", name); Cookie passwordCookie = new Cookie("password", password); //設置cookie的有效期 防止銷毀 nameCookie.setMaxAge(60*10);//10分鐘 passwordCookie.setMaxAge(60*10); //將cookie發送給客戶端保存 response.addCookie(nameCookie); response.addCookie(passwordCookie); } //登錄成功跳轉生鮮種類列表界面 response.sendRedirect(request.getContextPath()+"/category-list.jsp"); }else { //登錄失敗提示 response.setContentType("text/html;charset=utf-8"); response.getWriter().write("用戶登錄失敗"); } } protected 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 { //分別將屬性設置到對象中 // BeanUtils.setProperty(user,name,name); //將屬性的map集合封裝到對象中 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("注冊失敗"); } } } ~~~ 更改login.jsp相關內容   結果登錄與注冊功能沒問題