1、下载驱动，并把jar包放到Tomcat的lib目录下 下载连接
2、把jar包添加到项目中
3、登录页面
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>Insert title here</title> </head> <body> <form method="POST" name="frmLogin" action="LoginServlet"> <h1 align="center">用户登录</h1> <br /> 账号：<input type="text" name="username" size="20" maxlength="20" /><br> 密码：<input type="password" name="pwd" size="20" maxlength="20" /><br> <input type="submit" name="Submit" value="提交" onClick="return validateLogin()" /> <input type="reset" name="Reset" value="重置" /> </form> <script language="javascript"> function validateLogin(){ var sUserName = document.frmLogin.username.value ; var sPassword = document.frmLogin.password.value ; if (sUserName ==""){ alert("请输入用户名!"); return false ; } if (sPassword ==""){ alert("请输入密码!"); return false ; } } </script> </body> </html>
4、Servlet代码连接数据库
package me.letterwish.servlet; import java.io.IOException; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import com.mysql.jdbc.Connection; import com.mysql.jdbc.Statement; /** * Servlet implementation class LoginServlet */ @WebServlet("/LoginServlet") public class LoginServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public LoginServlet() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse * response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub response.getWriter().append("Served at: ").append(request.getContextPath()); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse * response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub response.setContentType("text/html;charset=utf-8"); request.setCharacterEncoding("utf-8"); String username = request.getParameter("username"); String pwd = request.getParameter("pwd"); try { Class.forName("com.mysql.jdbc.Driver"); } catch (ClassNotFoundException e) { e.printStackTrace(); System.out.println("找不到驱动 "); } // 连接URL 服务器地址 端口号 数据库名 String url = "jdbc:mysql://120.25.248.101:3306/letterwish"; Connection conn = null; Statement stmt = null; ResultSet rs = null; try { //数据可的登录名 登录密码 conn = (Connection) DriverManager.getConnection(url, "root", "root"); stmt = (Statement) conn.createStatement(); // SQL语句 String sql = "select * from users where account='" + username + "' and pwd= '" + pwd + "'"; rs = stmt.executeQuery(sql);// 返回查询结果 } catch (SQLException e) { e.printStackTrace(); } HttpSession session = request.getSession(); session.setAttribute("username", username); try { if (rs.next()) { // 如果记录集非空，表明有匹配的用户名和密码，登陆成功 response.sendRedirect("home.jsp"); } else { session.setAttribute("message", "用户名或密码不匹配。"); System.out.println("XXXXXXXXXX"); } } catch (SQLException e) { e.printStackTrace(); } } }