接父子工程项目搭建,继续扩展项目
重新调整模块结构
1.删除子模块fast-demo-web中所有无用内容

2.右键fast-demo-web名称->新建(news)->模块(Module),创建新的子模块

3.选择新建Maven工程

4.新建模块fast-demo-controller,注意:父项选择fast-demo-web而不是fast-demo

5.重复操作创建fast-demo-service、fast-demo-dao模块

- fast-demo-controller:专注写控制层代码,负责提供接口给前端对接
- fast-demo-service:专注写业务逻辑代码
- fast-demo-dao:专注处理数据,负责与数据库交互
简单实现数据库操作
1.每个子模块都新建对应的目录,如控制层增加controller目录存放控制层文件

2.添加MySQL和MyBatis-plus依赖
这里我们在fast-demo-web模块中的pom.xml里添加依赖而不是父工程
<!--引入mybatisPlus 包含了 jdbc-->
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
</dependency>
<!--mysql-->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>
子工程添加依赖不写版本,版本写在父工程的pom.xml,统一管理
<dependencyManagement>
    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-boot-starter</artifactId>
        <version>3.5.2</version>
    </dependency>
</dependencyManagement>
重新加载Maven后,三个子工程都会有MySQL和MyBatis-plus依赖包,但父工程没有

3.配置application.yml
在fast-demo-controller模块中的resources目录下新建application.yml,并增加数据库连接和MyBatis配置
# 数据库连接配置,记得新建一个数据库
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/my_demo?useUnicode=true&characterEncoding=UTF-8
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: 123456
    
mybatis-plus:
  # 指定 Mapper XML 文件的位置,使用 classpath 通配符指定路径
  mapper-locations: classpath:/mapper/**/*.xml
  # 指定实体类的包路径,用于自动扫描并注册类型别名
  type-aliases-package: com.cyfy.springboot_one.pojo
  global-config:
    db-config:
      id-type: input
      # 驼峰下划线转换(将数据库字段的下划线命名规则转换为 Java 实体类属性的驼峰命名规则)
      db-column-underline: true
      # 刷新 mapper
      refresh-mapper: true
  configuration:
    # 将 Java 实体类属性的驼峰命名规则转换为数据库字段的下划线命名规则
    map-underscore-to-camel-case: true
    # 查询结果中包含空值的列,在映射的时候,不会映射这个字段
    call-setters-on-nulls: true
    # 开启 sql 日志
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
    # 关闭 sql 日志
    # log-impl: org.apache.ibatis.logging.nologging.NoLoggingImpl
4.引用其他模块类
当我们需要引用其他模块的类时,需要在pom.xml中引入其他模块依赖,如service需要调用dao模块的方法,则需要在pom.xml中添加下如下代码
    <dependencies>
        <dependency>
            <groupId>com.cyfy</groupId>
            <artifactId>fast-demo-dao</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </dependency>
    </dependencies>
添加后,我们就可以在service模块中导入dao模块的类
 
同理,controller模块需要导入service模块的类,所以controller模块中的pom.xml需要添加如下代码
<dependencies>
    <dependency>
        <groupId>com.cyfy</groupId>
        <artifactId>fast-demo-service</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <scope>compile</scope>
    </dependency>
</dependencies>
注:虽然controller模块只引用了service模块,但因为service模块引用了dao模块,所以controller模块也能直接使用dao模块的类
项目结构

fast-demo-web模块
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">
    <parent>
        <artifactId>fast-demo</artifactId>
        <groupId>com.cyfy</groupId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>fast-demo-web</artifactId>
    <packaging>pom</packaging>
    <modules>
        <module>fast-demo-controller</module>
        <module>fast-demo-service</module>
        <module>fast-demo-dao</module>
    </modules>
    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>
    <dependencies>
        <!--引入mybatisPlus 包含了 jdbc-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
        </dependency>
        <!--mysql-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
    </dependencies>
</project>
fast-demo-controller模块
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">
    <parent>
        <artifactId>fast-demo-web</artifactId>
        <groupId>com.cyfy</groupId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>fast-demo-controller</artifactId>
    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>
    
    <dependencies>
        <dependency>
            <groupId>com.cyfy</groupId>
            <artifactId>fast-demo-service</artifactId>
            <version>0.0.1-SNAPSHOT</version>
            <scope>compile</scope>
        </dependency>
    </dependencies>
</project>
UserController
@RestController
public class UserController {
    @Autowired
    private UserService userService;
    @RequestMapping("/user")
    public List<User> user(){
        List<User> users = userService.getUserList();
        return users;
    }
}
FastDemoApplication
@SpringBootApplication
public class FastDemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(FastDemoApplication.class,args);
    }
}
fast-demo-service模块
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">
    <parent>
        <artifactId>fast-demo-web</artifactId>
        <groupId>com.cyfy</groupId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>fast-demo-service</artifactId>
    
    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>
    
    <dependencies>
        <dependency>
            <groupId>com.cyfy</groupId>
            <artifactId>fast-demo-dao</artifactId>
            <version>0.0.1-SNAPSHOT</version>
            <scope>compile</scope>
        </dependency>
    </dependencies>
</project>
UserService
public interface UserService {
    List<User> getUserList();
}
UserServiceImpl
@Service
public class UserServiceImpl implements UserService {
    @Autowired
    private UserMapper userMapper;
    @Override
    public List<User> getUserList() {
        return userMapper.selectList(null);
    }
}
fast-demo-dao模块
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">
    <parent>
        <artifactId>fast-demo-web</artifactId>
        <groupId>com.cyfy</groupId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>fast-demo-dao</artifactId>
    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>
</project>
UserMapper
@Mapper
public interface UserMapper extends BaseMapper<User> {
}
父工程fast-demo
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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.cyfy</groupId>
    <artifactId>fast-demo</artifactId>
    <packaging>pom</packaging>
    <version>0.0.1-SNAPSHOT</version>
    <modules>
        <module>fast-demo-web</module>
    </modules>
    <name>fast-demo</name>
    <description>fast-demo</description>
    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <spring-boot.version>2.6.13</spring-boot.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>3.5.2</version>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>${spring-boot.version}</version>
                <configuration>
                    <mainClass>com.cyfy.fastdemo.FastDemoApplication</mainClass>
                    <skip>true</skip>
                </configuration>
                <executions>
                    <execution>
                        <id>repackage</id>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>



















