2024/01/21
在servlet层来调用DAO层来实现数据库操作
这里根据查询数据库的返回值来选择跳转的页面，在输入的账号或密码错误时可以给出提示。
package com.example.demo; import bean.Base_InformationBean; import bean.InfoDAO; import jakarta.servlet.ServletException; import jakarta.servlet.annotation.WebServlet; import jakarta.servlet.http.HttpServlet; import jakarta.servlet.http.HttpServletRequest; import jakarta.servlet.http.HttpServletResponse; import java.io.IOException; import java.io.PrintWriter; @WebServlet(value="/login-servlet") public class LoginServlet extends HttpServlet { private String code; private String password; private Base_InformationBean hhh; public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException { code=request.getParameter("nameid"); password=request.getParameter("pwd"); hhh=new Base_InformationBean(); hhh.setCode(code); hhh.setPassword(password); boolean flag= new InfoDAO().Login(hhh); if(flag) { response.sendRedirect("success.jsp"); } else { request.setAttribute("msg","账号或密码错误"); try { request.getRequestDispatcher("index.jsp").forward(request,response); } catch (ServletException e) { throw new RuntimeException(e); } } } public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException { response.setContentType("text/html"); doGet(request,response); } }
我们要接受提示首先要给前面的<span>值一个初始的变量用于接收。
<span id="msg" style="font-size: 12px;color:red">${msg}</span><br>