在html页面输入内容与数据库验证是否匹配，即登录验证
数据库设计
login.html
<!DOCTYPE html> <html> <head> <title>login.html</title> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="this is my page"> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <meta http-equiv="Access-Control-Allow-Origin" content="*"> <!--<link rel="stylesheet" type="text/css" href="./styles.css">--> </head> <body> <label>用户名：</label><input id="nam" name="name"type="text" /> <label>密码：</label><input id="pass" name="password" type="password" /> <input id="register" type="button" value="登录" id="login"/> <input type="button" value="注册"/> </body> <script type="text/javascript" src="js/jquery-3.2.1.js"></script> <script type="text/javascript"> $("#register").click(function(){ var username=$("#nam").val(); var password=$("#pass").val(); if(username!=""&&password!=""){ $.ajax({ type:"POST", url:"search", dataType:"JSON", data:{ "username":username, "password":password } }) }else{ alert("请检查您的输入！"); } }) </script> </html>
search.java
package com.jquery.register; import java.io.IOException; import java.io.PrintWriter; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import javax.servlet.RequestDispatcher; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class search extends HttpServlet { public void destroy() { super.destroy(); } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); Connection conn = null; PreparedStatement stmt = null; ResultSet rs = null; String username = request.getParameter("username"); String password = request.getParameter("password"); System.out.println(username+password); String drive = "com.mysql.jdbc.Driver"; System.out.println("ajax后台交互成功"); try{ Class.forName(drive); conn = DriverManager .getConnection("jdbc:mysql://localhost:3306/test?user=root&password=123"); System.out.println("数据库连接成功"); String sql="select * from user_table where name='" + username + "' AND password='" + password + "'"; stmt = conn.prepareStatement(sql); rs=stmt.executeQuery(); System.out.println("success"); // while(rs.next()){ // String name = rs.getString(1); // String password = rs.getString(2); // System.out.println(name + ", " + password); // } if(rs.next()){ System.out.println("sys"); }else{ System.out.println("error"); } out.flush(); out.close(); }catch (ClassNotFoundException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); }finally { try { //注意关闭原则：从里到外 if (rs != null) { rs.close(); } if (stmt != null) { stmt.close(); } if (conn != null) { conn.close(); } } catch (SQLException e) { e.printStackTrace(); } } } public void init() throws ServletException { // Put your code here } }
