11. Respons - 11.5 用户登录和注册案例 - 《JavaWeb 教程》

mybatis-config配置信息

mybatis-config配置信息

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//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="123456"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <!--扫描mapper-->
        <package name="com.itheima.mapper"/>
    </mappers>
</configuration>

package com.itheima.web.reponse;
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.*;
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 {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // 接收用户名和密码
        // getParameter是根据 username所对应的键，获取该值  （就是获取用户名username所填入的值）
        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   （去官网查，不要记  改路径即可）
        String resource = "mybatis-config.xml"; // 在resources目录的下面，直接写名字即可
        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  映射对象 -- 找到映射接口，然后.class即可获取该对象
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        // 2.4 调用方法映射对象的查询（select）方法 来查询用户名密码
        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 type
        response.setContentType("text/html;charset=utf-8");
        // 获取响应的输出流，用来写用户登录成功和登录失败，打印其提示信息
        PrintWriter writer = response.getWriter();
        // 3. 判断user释放为null
        if (user != null){
            // 登录成功
            writer.write("登录成功");
        }else {
            // 登录失败
            writer.write("登录失败");
        }
    }
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request, response);
    }
}

package com.itheima.web.reponse;
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.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
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MyBatis完成查询
        // 2.1 获取SqlSessionFactory对象   （去官网查，不要记  改路径即可）
        String resource = "mybatis-config.xml"; // 在resources目录的下面，直接写名字即可
        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  映射对象 -- 找到映射接口，然后.class即可获取该对象
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        // 2.4 调用方法  // 查询是否存在该username 对象
        User u = userMapper.selectByUsername(username);
        // 3. 判断用户对象释放为null
        if ( u == null) {
            // 用户名不存在，添加用户(封装好的对象）
            userMapper.add(user);
            // 提交事务，一定要提交，因为要把数据提交到数据库，不提交就是临时的数据
            sqlSession.commit();
            // 释放资源
            sqlSession.close();
        }else {
            // 用户存在，给出提示信息
            response.setContentType("text/html;charset=utf-8");
            // 这里没有给对象名，但是还是创建了输出流对象（getWrite）,然后使用其write方法
            response.getWriter().write("用户名已经存在");
        }
    }
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.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="/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">
          <!-- 一点击按钮submit提交按钮，就能提交到from表单的action那个目录中去 -->
          <input value="注 册" type="submit" id="reg_btn">
        </div>
        <br class="clear">
      </form>
    </div>
  </body>
</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">
      <!-- 由于是表单，所以要设置虚拟目录(加模块名)  action是将表单提交到哪里 -->
      <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>