package com.itheima.web;
import com.itheima.mapper.UserMapper;
import com.itheima.pojo.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
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 java.io.IOException;
import java.io.InputStream;
@WebServlet("/registerServlet")
public class RegisterServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1.接受用户数据
String username = request.getParameter("username");
String password = request.getParameter("password");
//封装用户对象
User user = new User();
user.setUsername(username);
user.setPassword(password);
//2.调用mapper 根据用户名调查用户对象
//2.1 获取SqlSessionFactory对象
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.2 获取SqlSession对象
SqlSession sqlSession = sqlSessionFactory.openSession();
//2.3 获取Mapper
UserMapper UserMapper = sqlSession.getMapper(UserMapper.class);
//2.4 调用方法
User u = UserMapper.selectByUsername(username);
//3.判断用户对象是否为null
if (u == null){
//用户名不存在，可以添加用户
UserMapper.add(user);
//设置 防止乱码
response.setContentType("text/html;charset=utf-8");
//调用Writer输出
response.getWriter().write("注册成功");
//提交事务
sqlSession.commit();
//释放资源
sqlSession.close();
}else {
//用户名存在，给出提示信息
//设置 防止乱码
response.setContentType("text/html;charset=utf-8");
//调用Writer输出
response.getWriter().write("用户名已存在");
}
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request,response);
}
}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>欢迎注册</title>
<link href="css/register.css" rel="stylesheet">
</head>
<body>
<div class="form-div">
<div class="reg-content">
<h1>欢迎注册</h1>
<span>已有帐号？</span> <a href="login.html">登录</a>
</div>
<form id="reg-form" action="/RootDemo1/registerServlet" method="post">
<table>
<tr>
<td>用户名</td>
<td class="inputs">
<input name="username" type="text" id="username">
<br>
<span id="username_err" class="err_msg" style="display: none">用户名不太受欢迎</span>
</td>
</tr>
<tr>
<td>密码</td>
<td class="inputs">
<input name="password" type="password" id="password">
<br>
<span id="password_err" class="err_msg" style="display: none">密码格式有误</span>
</td>
</tr>
</table>
<div class="buttons">
<input value="注 册" type="submit" id="reg_btn">
</div>
<br class="clear">
</form>
</div>
</body>
</html>
package com.itheima.mapper;
import com.itheima.pojo.User;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
public interface UserMapper {
/*
* 根据用户名和密码查询用户对象
* */
@Select("select * from tb_user where username = #{username} and password =#{password}")
User select(@Param("username") String username,@Param("password") String password);
/*
* 根据用户名查询用户对象
* */
@Select("select * from tb_user where username=#{username}")
User selectByUsername(String username);
/*
* 添加用户
* */
@Insert("insert into tb_user values (null,#{username},#{password})")
void add(User user);
}
标签：username,用户名,用户注册,案例,User,import,password,user From： https://www.cnblogs.com/Karl-hut/p/17512549.html