RequestResponse案例

文章目录

一、用户登录
- 1、环境准备
- - 数据库准备
  - 导入MyBatis坐标，MySQL驱动坐标
  - mybatis-config.xml准备
  - UserMapper.xml
- 2、流程说明
- - UserMapper接口
  - login.html
  - LoginServlet
二、用户注册
- register.html
- RegisterServlet

一、用户登录

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1、环境准备

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数据库准备

create database db1;
-- 创建用户表
CREATE TABLE tb_user(id int primary key auto_increment,username varchar(20) unique,password varchar(32)
);-- 添加数据
INSERT INTO tb_user(username,password) values('zhangsan','123'),('lisi','234');SELECT * FROM tb_user;

导入MyBatis坐标，MySQL驱动坐标

        <dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.5</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.34</version></dependency>

mybatis-config.xml准备

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configurationPUBLIC "-//mybatis.org//DTD Config 3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration><!--起别名--><typeAliases><package name="com.itheima.pojo"/></typeAliases><environments default="development"><environment id="development"><transactionManager type="JDBC"/><dataSource type="POOLED"><property name="driver" value="com.mysql.jdbc.Driver"/><property name="url" value="jdbc:mysql:///db1?useSSL=false&amp;useServerPrepStmts=true"/><property name="username" value="root"/><property name="password" value="1234"/></dataSource></environment></environments><mappers><!--扫描mapper--><package name="com.itheima.mapper"/></mappers>
</configuration>

UserMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.itheima.mapper.UserMapper"></mapper>

2、流程说明

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UserMapper接口

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* @param username* @param password* @return*/@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* @param username* @return*/@Select("select * from tb_user where username = #{username}")User selectByUsername(String username);/*** 添加用户* @param user*/@Insert("insert into tb_user values(null,#{username},#{password})")void add(User user);
}

login.html

<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><title>login</title><link href="css/login.css" rel="stylesheet">
</head><body>
<div id="loginDiv"><form action="/request-demo/loginServlet" method="post" id="form"><h1 id="loginMsg">LOGIN IN</h1><p>Username:<input id="username" name="username" type="text"></p><p>Password:<input id="password" name="password" type="password"></p><div id="subDiv"><input type="submit" class="button" value="login up"><input type="reset" class="button" value="reset">&nbsp;&nbsp;&nbsp;<a href="register.html">没有账号？点击注册</a></div></form>
</div></body>
</html>

LoginServlet

package com.itheima.web;import com.itheima.mapper.UserMapper;
import com.itheima.pojo.User;
import com.itheima.util.SqlSessionFactoryUtils;
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.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//1. 接收用户名和密码String username = request.getParameter("username");String password = request.getParameter("password");//2. 调用MyBatis完成查询//2.1 获取SqlSessionFactory对象/* String resource = "mybatis-config.xml";InputStream inputStream = Resources.getResourceAsStream(resource);SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);*/SqlSessionFactory sqlSessionFactory = SqlSessionFactoryUtils.getSqlSessionFactory();//2.2 获取SqlSession对象SqlSession sqlSession = sqlSessionFactory.openSession();//2.3 获取MapperUserMapper userMapper = sqlSession.getMapper(UserMapper.class);//2.4 调用方法User user = userMapper.select(username, password);//2.5 释放资源sqlSession.close();//获取字符输出流，并设置content typeresponse.setContentType("text/html;charset=utf-8");PrintWriter writer = response.getWriter();//3. 判断user释放为nullif(user != null){// 登陆成功writer.write("登陆成功");}else {// 登陆失败writer.write("登陆失败");}}@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doGet(request, response);}
}

二、用户注册

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register.html

<!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="/request-demo/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>

RegisterServlet

package com.itheima.web;import com.itheima.mapper.UserMapper;
import com.itheima.pojo.User;
import com.itheima.util.SqlSessionFactoryUtils;
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.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.io.InputStream;@WebServlet("/registerServlet")
public class RegisterServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//1. 接收用户数据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 根据用户名查询用户对象//2.1 获取SqlSessionFactory对象/* String resource = "mybatis-config.xml";InputStream inputStream = Resources.getResourceAsStream(resource);SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);*/SqlSessionFactory sqlSessionFactory = SqlSessionFactoryUtils.getSqlSessionFactory();//2.2 获取SqlSession对象SqlSession sqlSession = sqlSessionFactory.openSession();//2.3 获取MapperUserMapper userMapper = sqlSession.getMapper(UserMapper.class);//2.4 调用方法User u = userMapper.selectByUsername(username);//3. 判断用户对象释放为nullif( u == null){// 用户名不存在，添加用户userMapper.add(user);// 提交事务sqlSession.commit();// 释放资源sqlSession.close();}else {// 用户名存在，给出提示信息response.setContentType("text/html;charset=utf-8");response.getWriter().write("用户名已存在");}}@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doGet(request, response);}
}