userMapper.java

package com.xd.web.mapper;import com.xd.web.pojo.User;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;import java.util.List;public interface UserMapper {@Select("select user_name from user1 limit 1")public String findUserName();//应该有一个查询全部//public List<Products> findAll();@Select("select * from user1 where user_name = #{name}")public List<User> ifExist(@Param("name") String userName);@Insert("insert into user1 (user_name,user_pwd) values(#{name},#{pwd})")public Integer register(@Param("name") String userName, @Param("pwd") String userPwd);@Select("select * from user1 where user_name = #{name} and user_pwd = #{pwd}")public List<User> login(@Param("name") String userName, @Param("pwd") String userPwd);
}

User.java

package com.xd.web.pojo;import java.io.Serializable;public class User implements Serializable {private String userName;private String userPwd;public User(String userName, String userPwd) {this.userName = userName;this.userPwd = userPwd;}public User() {}public String getUserName() {return userName;}public void setUserName(String userName) {this.userName = userName;}public String getUserPwd() {return userPwd;}public void setUserPwd(String userPwd) {this.userPwd = userPwd;}
}

DButil

package com.xd.web.utils;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 java.io.IOException;
import java.io.InputStream;public class DButil {private static SqlSessionFactory sqlSessionFactory = null;//测试环境下的工厂private static SqlSessionFactory sqlSessionFactoryTest = null;static {//1.builder  一旦创建了 SqlSessionFactory，就不再需要它了
//        SqlSessionFactoryBuilder sqlSessionFactoryBuilder =//2.获取工厂// 获取资源 org.apache.ibatis.io.Resources;try {InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");//根据资源文件创建工厂sqlSessionFactory  = new SqlSessionFactoryBuilder().build(inputStream);//测试环境的创建工厂
//            sqlSessionFactoryTest  = new SqlSessionFactoryBuilder().build(inputStream,"testdevelopment");} catch (IOException e) {throw new RuntimeException(e);}}public static SqlSession getSqlSession(){//获得Sqlsessionreturn sqlSessionFactory.openSession();}public static void close(SqlSession session){session.close();}}

LoginServlet.java

package com.xd.web;import com.xd.web.mapper.UserMapper;
import com.xd.web.pojo.User;
import com.xd.web.utils.DButil;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.util.Arrays;
import java.util.List;
import java.util.Map;/** http://localhost:8080/项目别名/映射*                              get ? name =111&pwd=1111* 浏览器地址栏中默认是get* */
@WebServlet("/login")
public class LoginServlet extends HttpServlet {//    @Override
//    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//
//        //获取请求部分
//        String requestURI = req.getRequestURI();
//
//        //获取参数
//        String param ;
//
//        if(req.getMethod().equals("get")){
//            //这是get的参数获取
//            param = req.getQueryString();
//            getDo();
//        }else {
//            //这是post的参数获取
//            param = req.getReader().readLine();
//            postDo();
//        }
//        //只有get常用
//        String getQueryString = req.getQueryString();//    name = 111&pwd =222
//
//        //post获取的是请求体中的数据流
//        BufferedReader reader = req.getReader();
//        //用io流去读
//        String postQueryString = reader.readLine();
//
//
//        System.out.println("get: "+getQueryString);
//        System.out.println("post: "+postQueryString);
//
//    }/****protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {response.setContentType("text/html");PrintWriter out = response.getWriter();out.println("<!DOCTYPE html>");out.println("<html>");out.println("<head><title>Dynamic Content</title></head>");out.println("<body>");out.println("<h1>Welcome, " + request.getParameter("name") + "!</h1>");out.println("</body>");out.println("</html>");
}**** */@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {this.doGet(req,resp);}@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//这三个函数是get和post通用的//获取所有参数的map集合
//        Map<String,String[]> getParameterMap()//获取的value类型是String数组类型//Map<String, String[]> parameterMap = req.getParameterMap();//等同于上面的map.get(s)//获得还是string数组//String[] likes = req.getParameterValues("like");//map.get(s)[0]//获取单一值//System.out.println("req.getParameter(\"like\") = " + req.getParameter("like"));//System.out.println("req.getParameter(\"name\") = " + req.getParameter("name"));//System.out.println("Arrays.toString(likes) = " + Arrays.toString(likes));//        for (String key : parameterMap.keySet()) {
//
//            String[] strings = parameterMap.get(key);
//
//            System.out.println(key+" : "+strings[0]);
//        }//获取usernameString username = req.getParameter("username");//获取passwordString password = req.getParameter("password");System.out.println(username+":"+password);//验证是否为admin admin
//UserMapper mapper = DButil.getSqlSession().getMapper(UserMapper.class);List<User> login = mapper.login(username, password);System.out.println(login);if (login!=null&&login.size()>0){System.out.println("走到succ");//成功了之后,我直接帮你跳转到一个资源的映射上去,我帮你找//帮你访问http://localhost:8080/webtom/login/failure.htmlreq.getRequestDispatcher("/login/success.html").forward(req,resp);} else {System.out.println("走到else");//返回对应结果req.getRequestDispatcher("/forwardtest").forward(req,resp);resp.getWriter().println("登录失败");}}
}

RegisterServlet.java

package com.xd.web;import com.xd.web.mapper.UserMapper;
import com.xd.web.pojo.User;
import com.xd.web.utils.DButil;
import org.apache.ibatis.session.SqlSession;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.util.List;@WebServlet("/regist")
public class RegisterServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {String username = req.getParameter("username");String password = req.getParameter("password");//先去看看这个用户名是不是存在了SqlSession sqlSession = DButil.getSqlSession();UserMapper mapper = sqlSession.getMapper(UserMapper.class);List<User> ifExist = mapper.ifExist(username);System.out.println(ifExist);if (ifExist !=null && ifExist.size()==0) {System.out.println("if");//如果返回值为0//执行函数,将这两个值放入数据库当中,insertInteger i = mapper.register(username,password);System.out.println(i);sqlSession.commit();//直接跳转到登录页面req.getRequestDispatcher("/login").forward(req,resp);}}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {this.doGet(req,resp);}
}

TestServlet.java

package com.xd.web;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;@WebServlet("/forwardtest")
public class TestServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {System.out.println(req.getContextPath());//post,直接用utf-8解码即可//req.setCharacterEncoding("UTF-8");//对于get请求,中文在uri当中就以及乱码了//逆向解析即可,先用8859去读,转为字节码,然后再用utf-8读//String name = req.getParameter("name");//乱码//byte[] bytes = name.getBytes("ISO-8859-1");//String s = new String(bytes, "UTF-8");//System.out.println("get");//        req.getRequestDispatcher("login/index").forward(req,resp);resp.sendRedirect(req.getContextPath()+"/login/failure.html");}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {System.out.println(req.getContextPath());System.out.println("post");}
}

user_id int  主键
user_name varchar 30
user_pwd varchar 50

mybatis-config.xml

<?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><environments default="development"><environment id="development"><transactionManager type="JDBC"/><dataSource type="POOLED"><property name="driver" value="com.mysql.cj.jdbc.Driver"/><property name="url" value="jdbc:mysql://localhost:3306/dict"/><property name="username" value="root"/><property name="password" value="123456"/></dataSource></environment></environments><mappers><mapper class="com.xd.web.mapper.UserMapper"/></mappers>
</configuration>

failure.html

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Login Failed</title>
</head>
<body>
<h1>Login fail</h1>
<p>Invalid username or password. Please try again.</p>
失败
</body>
</html>

success.html

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Login success</title>
</head>
<body>
<h1>Login success</h1>
<p>Invalid username or password. Please try again.</p>
成功
</body>
</html>

regist.html

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>注册页面</title><link rel="stylesheet" href="styles.css">
</head>
<body>
<div class="container"><h2>用户登录</h2><form action="registerServlet" method="post"><div class="form-group"><label for="username">用户名：</label><input type="text" id="username" name="username" required></div><div class="form-group"><label for="password">密码：</label><input type="password" id="password" name="password" required></div><div class="form-group"><label for="confirmPassword">确认密码：</label><input type="password" id="confirmPassword" name="confirmPassword" required></div><button type="submit">注册</button></form>
</div>
</body>
</html>

pom.xml

<?xml version="1.0" encoding="UTF-8"?><project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>org.example</groupId><artifactId>login_register</artifactId><version>1.0-SNAPSHOT</version><packaging>war</packaging><name>login_register Maven Webapp</name><!-- FIXME change it to the project's website --><url>http://maven.apache.org</url><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><maven.compiler.source>1.7</maven.compiler.source><maven.compiler.target>1.7</maven.compiler.target></properties><dependencies><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.11</version><scope>test</scope></dependency><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.15</version></dependency><dependency><groupId>com.mysql</groupId><artifactId>mysql-connector-j</artifactId><version>8.0.31</version></dependency><dependency><groupId>javax.servlet</groupId><artifactId>javax.servlet-api</artifactId><version>3.1.0</version><scope>provided</scope></dependency></dependencies><build><finalName>login_register</finalName></build>
</project>