Spring Boot 多模块与 Maven 私有仓库
前言
系统复杂了，抽离单一职责的模块几乎是必须的；若需维护多个项目，抽离公用包上传私有仓库管理也几乎是必须的。其优点无需赘述，以下将记录操作过程。
1. 多模块拆分
在.NET 中由于其统一性，实现上更自然一点。Spring Boot 通过 Maven 构建多模块工程也不麻烦，假如我的项目中包含以下几个包：
我需要将他们分别拆分成独立模块，首先要修改的是根目录下的 pom.xml，packaging 类型改为 pom，并添加 modules 节点:
<?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>com.youclk.multi-package</groupId>
<artifactId>parent</artifactId>
<version>0.0.1-SNAPSHOT</version>
<modules>
<module>api</module>
<module>service</module>
<module>dao</module>
</modules>
<packaging>pom</packaging>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.10.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
<lombok>1.16.20</lombok>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>${lombok}</version>
</dependency>
</dependencies>
</project>
之后新建一个个 Module，将对应的代码移植过去：
需要注意的是在启动模块的 pom.xml 中需要指定启动类：
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<mainClass>com.youclk.multipackage.api.MultiApplication</mainClass>
<layout>ZIP</layout>
</configuration>
</plugin>
</plugins>
</build>
统一升级版本命令：mvn versions:set -DnewVersion=0.0.1-SNAPSHOT，到此差不多完成了，引用方式与普通的依赖包一致：
<dependency>
<groupId>com.youclk.multi-package</groupId>
<artifactId>service</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
补充
外层 pom ：
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.youclk</groupId>
<artifactId>et2</artifactId>
<packaging>pom</packaging>
<version>${own-project.version}</version>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.0.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<modules>
<module>start</module>
<module>service</module>
<module>client</module>
</modules>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
<own-project.version>1.0.0</own-project.version>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>com.youclk</groupId>
<artifactId>start</artifactId>
<version>${own-project.version}</version>
</dependency>
<dependency>
<groupId>com.youclk</groupId>
<artifactId>service</artifactId>
<version>${own-project.version}</version>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
</dependencies>
</project>
内层 pom
<?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>
<parent>
<groupId>com.youclk</groupId>
<artifactId>et2</artifactId>
<version>1.0.0</version>
</parent>
<artifactId>service</artifactId>
<packaging>jar</packaging>
<version>${own-project.version}</version>
</project>
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.youclk</groupId>
<artifactId>et2</artifactId>
<version>1.0.0</version>
</parent>
<artifactId>start</artifactId>
<packaging>jar</packaging>
<version>${own-project.version}</version>
<dependencies>
<dependency>
<groupId>com.youclk</groupId>
<artifactId>service</artifactId>
</dependency>
</dependencies>
</project>
注意 start 模块下的包结构为根结构，不要加 .start，否则要指定需要扫描的包。
2. Nexus3 私有仓库搭建
Docker 时代一切都变得异常简单，Compose 配置如下：
version: '3.5'
services:
nexus:
image: sonatype/nexus3:3.10.0
networks:
- proxy
- youclk
volumes:
- /mnt/nas/db/nexus-data:/nexus-data
deploy:
mode: replicated
labels:
- com.df.notify=true
- com.df.port=8081
- com.df.serviceDomain=nexus.youclk.com
restart_policy:
condition: any
max_attempts: 3
update_config:
delay: 5s
order: start-first
resources:
limits:
cpus: '0.50'
memory: 1g
networks:
proxy:
external: true
youclk:
external: true
启动过程需要一分钟左右：
需要注意的是如果你的 ssl 是在负载均衡或者其他的反向代理之上，那么必须在 HTTP 头中指定 X-Forwarded-Proto 传输协议为 HTTPS，然后，就可以愉快地玩耍了。
3. 上传与引用
3.1 上传
首先需要在 Nexus 创建私有仓库，例如我的：
其次在本地 maven 设置中添加 server 节点，默认在 ~/.m2/settings.xml：
<servers>
<server>
<id>youclk</id>
<username>admin</username>
<password>youclk</password>
</server>
</servers>
pom.xml 中添加上传地址：
<distributionManagement>
<repository>
<id>nexus</id>
<name>Releases Repository</name>
<url>https://nexus.youclk.com/repository/youclk-releases/</url>
</repository>
<snapshotRepository>
<id>nexus</id>
<name>Snapshot Repository</name>
<url>https://nexus.youclk.com/repository/youclk-snapshots/</url>
</snapshotRepository>
</distributionManagement>
最后执行 mvn clean deploy 便会上传至私有仓库，单独传包命令如下：
mvn deploy:deploy-file -DgroupId=com.youclk -DartifactId=utils -Dversion=0.0.1-SNAPSHOT -Dpackaging=jar -Dfile=target/utils-0.0.1-SNAPSHOT.jar -Durl=https://nexus.youclk.com/repository/youclk/ -DrepositoryId=youclk
管理和查看：
3.1 引用
Finally，最后的最后就是怎么使用啦~ 如果需要全局引用的话需要在 settings.xml 添加和激活仓库：
<?xml version="1.0" encoding="UTF-8"?>
<settings>
<mirrors>
<mirror>
<id>aliyun</id>
<mirrorOf>central</mirrorOf>
<name>central mirror</name>
<url>http://maven.aliyun.com/mvn/repository</url>
</mirror>
<mirror>
<id>nexus</id>
<mirrorOf>maven-public</mirrorOf>
<name>private mirror</name>
<url>http://local-nexus.youclk.com/repository/maven-public/</url>
</mirror>
</mirrors>
<servers>
<server>
<id>nexus</id>
<username>admin</username>
<password>youclk</password>
</server>
</servers>
<profiles>
<profile>
<id>nexus</id>
<repositories>
<repository>
<id>maven</id>
<name>local private nexus</name>
<url>http://local-nexus.youclk.com/repository/maven-public/</url>
<releases>
<enabled>true</enabled>
</releases>
<snapshots>
<enabled>true</enabled>
</snapshots>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>maven</id>
<name>local private nexus</name>
<url>http://local-nexus.youclk.com/repository/maven-public/</url>
<releases>
<enabled>true</enabled>
</releases>
<snapshots>
<enabled>true</enabled>
</snapshots>
</pluginRepository>
</pluginRepositories>
</profile>
</profiles>
<activeProfiles>
<activeProfile>nexus</activeProfile>
</activeProfiles>
</settings>
不过一般不推荐这么写，settings.xml 应该尽可能保持简洁，精简配置，此处留下代理和权限认证即可，其余的可以移植到 pom.xml 中：
<repositories>
<repository>
<id>aliyun</id>
<url>http://maven.aliyun.com/nexus/content/groups/public/</url>
</repository>
<repository>
<id>nexus</id>
<url>http://local-nexus.youclk.com/repository/maven-public/</url>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>central</id>
<url>
http://maven.aliyun.com/nexus/content/groups/public/
</url>
</pluginRepository>
<pluginRepository>
<id>maven-public</id>
<url>http://local-nexus.youclk.com/repository/maven-public/</url>
</pluginRepository>
</pluginRepositories>
小结
我的公众号《有刻》，我们共同成长！
作者：捷义
出处：http://www.cnblogs.com/youclk/
说明：转载请标明来源和作者
