idea写一个javaweb实现登录注册基于（spring mvc,mysql,maven）的代码并且将项目完整结构写下来

好的，以下是一个基于 Spring MVC、MySQL 和 Maven 的简单登录注册系统的代码示例及其完整项目结构：

1. 项目结构

|- src/main/java
     |- com.example.demo
          |- controller
               |- UserController.java
          |- dao
               |- UserDAO.java
          |- model
               |- User.java
          |- service
               |- UserService.java
               |- UserServiceImpl.java
|- src/main/resources
     |- application.properties
     |- log4j.properties
|- src/main/webapp
     |- WEB-INF
          |- views
               |- index.jsp
               |- login.jsp
               |- register.jsp
          |- web.xml
     |- index.jsp
     |- login.jsp
     |- register.jsp
|- pom.xml

2. 相关依赖和配置

pom.xml：

<dependencies>
    <!-- Spring MVC -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>5.3.6</version>
    </dependency>

    <!-- MySQL -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.23</version>
    </dependency>

    <!-- MyBatis -->
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.7</version>
    </dependency>

    <!-- MyBatis-Spring -->
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>2.0.6</version>
    </dependency>

    <!-- Spring JDBC -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>5.3.6</version>
    </dependency>

    <!-- Spring TX -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-tx</artifactId>
        <version>5.3.6</version>
    </dependency>

    <!-- Spring Test -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-test</artifactId>
        <version>5.3.6</version>
    </dependency>

    <!-- Junit -->
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
        <scope>test</scope>
    </dependency>
</dependencies>

application.properties：

# MySQL 数据库配置
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/user_db?useSSL=false&serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8
spring.datasource.username=root
spring.datasource.password=123456

# MyBatis 配置
mybatis.mapper-locations=classpath:mapper/*.xml
mybatis.type-aliases-package=com.example.demo.model

web.xml：

<web-app xmlns="http://java.sun.com/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
         http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
         version="3.0">
         
    <display-name>My Login App</display-name>

    <!-- 配置 Spring MVC -->
    <servlet>
        <servlet-name>dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring/spring-mvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>dispatcher</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <!-- 编码过滤器 -->
    <filter>
        <filter-name>encodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
        <init-param>
            <param-name>forceEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>

    <filter-mapping>
        <filter-name>encodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
</web-app>

spring-mvc.xml：

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="
            http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context.xsd
            http://www.springframework.org/schema/mvc
            http://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!-- 开启注解扫描 -->
    <context:component-scan base-package="com.example.demo"/>

    <!-- 开启 Spring MVC 注解驱动 -->
    <mvc:annotation-driven/>

    <!-- 配置视图解析器 -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

    <!-- 配置数据源 -->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="${spring.datasource.driver-class-name}"/>
        <property name="url" value="${spring.datasource.url}"/>
        <property name="username" value="${spring.datasource.username}"/>
        <property name="password" value="${spring.datasource.password}"/>
    </bean>

    <!-- 配置 MyBatis -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="typeAliasesPackage" value="com.example.demo.model"/>
        <property name="mapperLocations" value="classpath:mapper/*.xml"/>
    </bean>

    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.example.demo.dao"/>
    </bean>

    <!-- 配置事务管理器 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    <tx:annotation-driven transaction-manager="transactionManager"/>
</beans>

3. 实体类

User.java：

public class User {
    private int id;
    private String username;
    private String password;

    // getter 和 setter 略

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

4. DAO 层

UserDAO.java：

public interface UserDAO {
    User getUserById(int id);
    User getUserByUsername(String username);
    void addUser(User user);
}

UserDAO.xml：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.demo.dao.UserDAO">
    <resultMap id="userResultMap" type="com.example.demo.model.User">
        <id column="id" property="id" jdbcType="INTEGER"/>
        <result column="username" property="username" jdbcType="VARCHAR"/>
        <result column="password" property="password" jdbcType="VARCHAR"/>
    </resultMap>

    <select id="getUserById" resultMap="userResultMap">
        SELECT * FROM user WHERE id = #{id}
    </select>

    <select id="getUserByUsername" resultMap="userResultMap">
        SELECT * FROM user WHERE username = #{username}
    </select>

    <insert id="addUser">
        INSERT INTO user (username, password) VALUES (#{username}, #{password})
    </insert>
</mapper>

5. Service 层

UserService.java：

public interface UserService {
    User getUserById(int id);
    User getUserByUsername(String username);
    void addUser(User user);
}

UserServiceImpl.java：

@Service
public class UserServiceImpl implements UserService {
    @Autowired
    private UserDAO userDAO;

    @Override
    public User getUserById(int id) {
        return userDAO.getUserById(id);
    }

    @Override
    public User getUserByUsername(String username) {
        return userDAO.getUserByUsername(username);
    }

    @Override
    public void addUser(User user) {
        userDAO.addUser(user);
    }
}

6. Controller 层

UserController.java：

@Controller
public class UserController {
    @Autowired
    private UserService userService;

    @RequestMapping(value = "/")
    public String index() {
        return "index";
    }

    @RequestMapping(value = "/login", method = RequestMethod.GET)
    public String login() {
        return "login";
    }

    @RequestMapping(value = "/login", method = RequestMethod.POST)
    public ModelAndView login(String username, String password) {
        User user = userService.getUserByUsername(username);
        if (user != null && user.getPassword().equals(password)) {
            ModelAndView mav = new ModelAndView("index");
            mav.addObject("user", user);
            return mav;
        } else {
            return new ModelAndView("login", "error", "用户名或密码错误！");
        }
    }

    @RequestMapping(value = "/register", method = RequestMethod.GET)
    public String register() {
        return "register";
    }

    @RequestMapping(value = "/register", method = RequestMethod.POST)
    public ModelAndView register(User user) {
        userService.addUser(user);
        ModelAndView mav = new ModelAndView("index");
        mav.addObject("user", user);
        return mav;
    }
}

7. 视图

index.jsp：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>首页</title>
</head>
<body>
    <h1>欢迎您，${user.username}！</h1>
</body>
</html>

login.jsp：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>登录</title>
</head>
<body>
    <form method="post" action="/login">
        <label for="username">用户名：</label>
        <input type="text" id="username" name="username"><br>
        <label for="password">密码：</label>
        <input type="password" id="password" name="password"><br>
        <input type="submit" value="登录">
    </form>
    <p style="color: red">${error}</p>
</body>
</html>

register.jsp：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>注册</title>
</head>
<body>
    <form method="post" action="/register">
        <label for="username">用户名：</label>
        <input type="text" id="username" name="username"><br>
        <label for="password">密码：</label>
        <input type="password" id="password" name="password"><br>
        <input type="submit" value="注册">
    </form>
</body>
</html>

以上就是一个简单的基于 Spring MVC、MySQL 和 Maven 的登录注册系统的代码示例及其完整项目结构，希望能对你有所帮助。