index.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title></title> </head> <body> <form method="post" action="register.jsp"> 用户名:<input type="text" name="username"><br> 密码: <input type="text" name="password"><br> 性别: <input type="text" name="gender"><br> 年龄: <input type="text" name="age"><br> <button type="submit">注册</button> </form> </body> </html>register.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Title</title> </head> <body> <% //user对象实例化 UserBean user = new UserBean(); //给对象赋值 user.setUsername(request.getParameter("username")); user.setPassword(request.getParameter("password")); //数据库操作 //1 加载驱动程序 Class.forName("com.mysql.jdbc.Driver"); //如果执行到此位置报错 标识驱动的jar包没有加载成功 //2 建立数据库连接 10.3.22.1 String url = "jdbc:mysql://127.0.0.1:3306/book?user=root&password=root";//book 为数据库名 Connection connection = DriverManager.getConnection(url);//获得连接对象 //alt + 回车 自动导入类 如果报此行有问题说明 数据库的连接地址或用户名和密码有问题 //3 创建Statement对象 执行sql语句 alt+enter 自动引入缺失的类 Statement stmt = connection.createStatement(); // sql 插入语句值是字符串 必须使用单引号 String sql = "insert into user (username,password,gender,age) values('"+user.getUsername()+"','"+user.getPassword()+"',1,23)"; //String sql = "update user set status = 3 where id = 11"; //tring sql = "delete from user where id = 17"; //执行sql语句时id 保证数据库中存在该数据 //使用Statement 对象执行sql语句 增删改的数据库操作使用executeUpdate int count = stmt.executeUpdate(sql); //如果报此行有错误 数码上一行的sql语句是有问题的 请检查数据库 if(count == 0 ){ out.print("注册失败"); //如果能执行到此位置 表示数据库操作是成功 数据库的数据是没有发生变化 否则的肯定有异常 }else{ out.print("注册成功"); } %> </body> </html>home.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Title</title> </head> <body> <% //加载数据库驱动 Class.forName("com.mysql.jdbc.Driver"); //建立数据库连接 //数据库连接地址 String url = "jdbc:mysql://localhost:3306/book"; Connection connection = DriverManager.getConnection(url,"root","root"); //第一个root为数据库的用户名 第二个root为数据库的密码 String sql = "select * from user where username = ? and password = ?"; //在PreparedStatement 中使用问好代替实际参数 PreparedStatement ps = connection.prepareStatement(sql); ps.setString(1,request.getParameter("username")); ps.setString(2,request.getParameter("password")); // String sql = "insert into user(username,password,gender) values (?,?,?)"; ResultSet rs = ps.executeQuery(); while (rs.next()){ out.print(rs.getString("username")+"-"+rs.getString(3)+"<br>"); } /* //使用Statement对象执行sql语句 Statement stmt = connection.createStatement(); //stmt.executeUpdate() 执行增删改操作的函数 String sql = "select * from user where username = '"+request.getParameter("username")+"'"; ResultSet rs = stmt.executeQuery(sql); //执行查询的函数 返回结果集 while (rs.next()){ out.print(rs.getString("username")+"-"+rs.getString(3)+"<br>"); } */ %> </body> </html>UserBean
package com.media.bean; public class UserBean { private String username; private String password; private int gender; private int age; private int status; public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public int getGender() { return gender; } public void setGender(int gender) { this.gender = gender; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public int getStatus() { return status; } public void setStatus(int status) { this.status = status; } }