parent管理cloud版本
common管理第三方依赖包
order无需再引入

1. 先建一个springboot项目 然后删除掉src目录 这个时候只留下了.idea, .iml 和pom.xml
   编辑pom文件

<?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>
	<!-- springboot的版本 -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <groupId>cn.lwd</groupId>
    <artifactId>parent</artifactId>
    <version>1.0-SNAPSHOT</version>
    <name>wd-parent</name>
    <packaging>pom</packaging>
    <description>wd-parent-dependencies</description>

    <properties>
        <java.version>1.8</java.version>
        <!-- springcloud版本 -->
        <spring-cloud.version>Hoxton.SR8</spring-cloud.version>
        <!-- springcloud alibaba本本 -->
        <spring-cloud-alibaba.version>2.2.4.RELEASE</spring-cloud-alibaba.version>
    </properties>

	<!-- 重点在这里 会把相关依赖版本都约束 module微服务模块 可以直接引入相关依赖而不用标注version -->
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${spring-cloud-alibaba.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

        </dependencies>
    </dependencyManagement>
</project>

2. 在刚才创建的parent项目下 再创建一个springboot项目 起名为common 里面存放通用service和常用jar包以及版本
   编辑pom文件

<?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>
    <!-- 这里的parent就是刚才的pom的相关groupId和artifactId -->
    <parent>
        <groupId>cn.lwd</groupId>
        <artifactId>parent</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <groupId>cn.lwd</groupId>
    <artifactId>common</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>wd-common</name>
    <description>wd-common</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <!-- 引入常用依赖jar -->
    <dependencies>
        <!--HikariCP连接池-->
        <dependency>
            <groupId>com.zaxxer</groupId>
            <artifactId>HikariCP</artifactId>
        </dependency>
        <!--mybatis-plus -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.2.0</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.17</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.10</version>
        </dependency>

        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpcore</artifactId>
            <version>4.4.12</version>
        </dependency>

        <dependency>
            <groupId>commons-lang</groupId>
            <artifactId>commons-lang</artifactId>
            <version>2.6</version>
        </dependency>

        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.2</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

3. 在parent项目下 再创建子module order微服务模块. 这个模块的pom文件就可以非常的清晰 简洁了

<?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>
    <!-- 最外层的cloud版本限制 -->
    <parent>
        <groupId>cn.lwd</groupId>
        <artifactId>parent</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <groupId>cn.lwd</groupId>
    <artifactId>order</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>wd-order</name>
    <description>wd-order</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
   		<!-- common模块的常用jar -->
        <dependency>
            <groupId>cn.lwd</groupId>
            <artifactId>common</artifactId>
            <version>0.0.1-SNAPSHOT</version>
            <scope>compile</scope>
        </dependency>

        <!-- 服务注册与发现 -->
        <!-- 这里就可以不用写version -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

4. order服务application上 直接写mybatis datasource和nacos相关配置参数 就可以直接启动了.