spring-boot-dependencies、spring-boot-starter-parent、io.spring.platform详解

上一篇文章介绍了springboot依赖版本号管理的几种方式，现在来详细分析一下spring-boot-dependencies、spring-boot-starter-parent、io.spring.platform是如何进行版本号控制的，各自有什么作用和区别。

一、spring-boot-dependencies、spring-boot-starter-parent、io.spring.platform三者是继承关系

1.spring-boot-starter-parent继承spring-boot-dependencies

2.io.spring.platform继承spring-boot-starter-parent

 二、spring-boot-dependencies

从继承的源点spring-boot-dependencies开始看

1.pom.xml里的dependencyManagement节点

dependencyManagement节点的作用是统一maven引入依赖JAR包的版本号，可以看出spring-boot-dependencies最重要的一个作用就是对springboot可能用到的依赖JAR包做了版本号的控制管理

2.pom.xml里的pluginManagement节点

pluginManagement节点的作用是统一maven引入插件的版本号，可以看出spring-boot-dependencies另一个作用是对springboot可能用到的插件做了版本号的控制管理

3.pom.xml里的plugins节点

spring-boot-dependencies引入（或覆盖）了三个插件：

maven-help-plugin：用于获取有关项目或系统的帮助信息；这个插件是Maven自带的插件，这里进行了覆盖设置；设置inherited（是否继承）为false；设置phase为generate-resources、goal为effective-pom的配置output

<plugin>
  <artifactId>maven-help-plugin</artifactId>
  <inherited>false</inherited>
  <executions>
    <execution>
      <id>generate-effective-dependencies-pom</id>
      <phase>generate-resources</phase>
      <goals>
        <goal>effective-pom</goal>
      </goals>
      <configuration>
        <output>${project.build.directory}/effective-pom/spring-boot-dependencies.xml</output>
      </configuration>
    </execution>
  </executions>
</plugin>

xml-maven-plugin：处理XML相关

<plugin>
  <groupId>org.codehaus.mojo</groupId>
  <artifactId>xml-maven-plugin</artifactId>
  <version>1.0</version>
  <inherited>false</inherited>
  <executions>
    <execution>
      <goals>
        <goal>transform</goal>
      </goals>
    </execution>
  </executions>
  <configuration>
    <transformationSets>
      <transformationSet>
        <dir>${project.build.directory}/effective-pom</dir>
        <stylesheet>src/main/xslt/single-project.xsl</stylesheet>
        <outputDir>${project.build.directory}/effective-pom</outputDir>
      </transformationSet>
    </transformationSets>
  </configuration>
</plugin>

build-helper-maven-plugin：用于设置主源码目录、测试源码目录、主资源文件目录、测试资源文件目录等

<plugin>
  <groupId>org.codehaus.mojo</groupId>
  <artifactId>build-helper-maven-plugin</artifactId>
  <inherited>false</inherited>
  <executions>
    <execution>
      <id>attach-artifacts</id>
      <phase>package</phase>
      <goals>
        <goal>attach-artifact</goal>
      </goals>
      <configuration>
        <artifacts>
          <artifact>
            <file>${project.build.directory}/effective-pom/spring-boot-dependencies.xml</file>
            <type>effective-pom</type>
          </artifact>
        </artifacts>
      </configuration>
    </execution>
  </executions>
</plugin>

这三个插件共同完成了一件事，将spring-boot-dependencies（springboot在项目里使用到的依赖）输出到XML，并且打包install到仓库。

这些就是spring-boot-dependencies主要的作用了，管理控制依赖版本号，管理控制插件版本号以及引入了3个辅助插件。

三、spring-boot-starter-parent

 spring-boot-starter-parent继承spring-boot-dependencies

1.pom.xml里的properties节点

spring-boot-starter-parent在properties节点里添加了一些预设配置

java.version：jdk的版本号

<java.version>1.6</java.version>

resource.delimiter：设定占位符为@

<resource.delimiter>@</resource.delimiter>

project.build.sourceEncoding、project.reporting.outputEncoding：设置编码为UTF-8

<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>

maven.compiler.source、maven.compiler.target：设置编译打包的jdk版本

<maven.compiler.source>${java.version}</maven.compiler.source>
<maven.compiler.target>${java.version}</maven.compiler.target>

2.pom.xml里的dependencyManagement节点

覆盖了spring-boot-dependencies的spring-core依赖引入，去掉了spring-core里的commons-logging依赖

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-core</artifactId>
  <version>${spring.version}</version>
  <exclusions>
    <exclusion>
      <groupId>commons-logging</groupId>
      <artifactId>commons-logging</artifactId>
    </exclusion>
  </exclusions>
</dependency>

3.pom.xml里的bulid->resources节点

设置了application.properties配置文件的读取目录在/src/main/resources目录下

<resource>
  <directory>${basedir}/src/main/resources</directory>
  <filtering>true</filtering>
  <includes>
    <include>**/application*.yml</include>
    <include>**/application*.yaml</include>
    <include>**/application*.properties</include>
  </includes>
</resource>
<resource>
  <directory>${basedir}/src/main/resources</directory>
  <excludes>
    <exclude>**/application*.yml</exclude>
    <exclude>**/application*.yaml</exclude>
    <exclude>**/application*.properties</exclude>
  </excludes>
</resource>

4.pom.xml里的pluginManagement节点

覆盖了spring-boot-dependencies的一些插件版本控制管理：maven-failsafe-plugin、maven-jar-plugin、maven-surefire-plugin、maven-war-plugin、exec-maven-plugin、maven-resources-plugin、git-commit-id-plugin、spring-boot-maven-plugin、maven-shade-plugin

maven-failsafe-plugin：配置了绑定Maven打包时integration-test、verify阶段

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-failsafe-plugin</artifactId>
  <executions>
    <execution>
      <goals>
        <goal>integration-test</goal>
        <goal>verify</goal>
      </goals>
    </execution>
  </executions>
</plugin>

maven-jar-plugin：添加了启动类配置和扫描默认实现JAR包配置

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-jar-plugin</artifactId>
  <configuration>
    <archive>
      <manifest>
        <mainClass>${start-class}</mainClass>
        <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
      </manifest>
    </archive>
  </configuration>
</plugin>

maven-surefire-plugin：配置了Maven打包时单元测试扫描**/*Tests.java、**/*Test.java类，排除**/Abstract*.java类

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-surefire-plugin</artifactId>
  <configuration>
    <includes>
      <include>**/*Tests.java</include>
      <include>**/*Test.java</include>
    </includes>
    <excludes>
      <exclude>**/Abstract*.java</exclude>
    </excludes>
  </configuration>
</plugin>

maven-war-plugin：配置了可以没有web.xml文件进行启动；添加了启动类配置和扫描默认实现JAR包配置

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-war-plugin</artifactId>
  <configuration>
    <failOnMissingWebXml>false</failOnMissingWebXml>
    <archive>
      <manifest>
        <mainClass>${start-class}</mainClass>
        <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
      </manifest>
    </archive>
  </configuration>
</plugin>

exec-maven-plugin：添加了启动类配置

<plugin>
  <groupId>org.codehaus.mojo</groupId>
  <artifactId>exec-maven-plugin</artifactId>
  <configuration>
    <mainClass>${start-class}</mainClass>
  </configuration>
</plugin>

maven-resources-plugin：配置了资源占位符为 @

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-resources-plugin</artifactId>
  <version>2.6</version>
  <configuration>
    <delimiters>
      <delimiter>${resource.delimiter}</delimiter>
    </delimiters>
    <useDefaultDelimiters>false</useDefaultDelimiters>
  </configuration>
</plugin>

git-commit-id-plugin：配置了绑定Maven打包修订阶段revision的GIT版本号变化；配了verbose为ture；配置了日期格式为yyyy-MM-dd'T'HH:mm:ssZ；配置了生成GIT .properties文件，文件名为${project.build.outputDirectory}/git.properties

<plugin>
  <groupId>pl.project13.maven</groupId>
  <artifactId>git-commit-id-plugin</artifactId>
  <executions>
    <execution>
      <goals>
        <goal>revision</goal>
      </goals>
    </execution>
  </executions>
  <configuration>
    <verbose>true</verbose>
    <dateFormat>yyyy-MM-dd'T'HH:mm:ssZ</dateFormat>
    <generateGitPropertiesFile>true</generateGitPropertiesFile>
    <generateGitPropertiesFilename>${project.build.outputDirectory}/git.properties</generateGitPropertiesFilename>
  </configuration>
</plugin>

spring-boot-maven-plugin：配置了绑定Maven打包repackage阶段插件的使用；配置了启动类

<plugin>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-maven-plugin</artifactId>
  <executions>
    <execution>
      <goals>
        <goal>repackage</goal>
      </goals>
    </execution>
  </executions>
  <configuration>
    <mainClass>${start-class}</mainClass>
  </configuration>
</plugin>

maven-shade-plugin：覆盖引入spring-boot-maven-plugin依赖JAR；配置keepDependenciesWithProvidedScope为true；配置createDependencyReducedPom为true；过滤掉META-INF/*.SF、META-INF/*.DSA、META-INF/*.RSA，防止重复引用打包失败；配置绑定Maven打包package阶段shade；

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-shade-plugin</artifactId>
  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-maven-plugin</artifactId>
      <version>1.5.4.RELEASE</version>
    </dependency>
  </dependencies>
  <configuration>
    <keepDependenciesWithProvidedScope>true</keepDependenciesWithProvidedScope>
    <createDependencyReducedPom>true</createDependencyReducedPom>
    <filters>
      <filter>
        <artifact>*:*</artifact>
        <excludes>
          <exclude>META-INF/*.SF</exclude>
          <exclude>META-INF/*.DSA</exclude>
          <exclude>META-INF/*.RSA</exclude>
        </excludes>
      </filter>
    </filters>
  </configuration>
  <executions>
    <execution>
      <phase>package</phase>
      <goals>
        <goal>shade</goal>
      </goals>
      <configuration>
        <transformers>
          <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
            <resource>META-INF/spring.handlers</resource>
          </transformer>
          <transformer implementation="org.springframework.boot.maven.PropertiesMergingResourceTransformer">
            <resource>META-INF/spring.factories</resource>
          </transformer>
          <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
            <resource>META-INF/spring.schemas</resource>
          </transformer>
          <transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer"/>
          <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
            <mainClass>${start-class}</mainClass>
          </transformer>
        </transformers>
      </configuration>
    </execution>
  </executions>
</plugin>

 四、io.spring.platform

io.spring.platform继承spring-boot-starter-parent

1.pom.xml里的properties节点

io.spring.platform一个最大的作用便是将经过集成测试的各类依赖版本号进行整合。

在平时开发中，需要某个JAR包依赖往往是习惯性的找最新版本，或是根据经验选择一个版本；

单对某个JAR包来讲，没有任何问题，但当过多的JAR包依赖整合到一起的时候，就可能会出现各自版本不适配的情况产生，产生BUG漏洞的场景将大大增加；

io.spring.platform所做的事情就是将做过集成测试JAR包依赖整合到一起，大大降低了漏洞出现的可能性。

2.pom.xml里的dependencyManagement节点

覆盖所有父节点里的依赖引入并增加部分新的依赖，使用properties节点里的版本号

3.pom.xml里的plugins节点

覆盖spring-boot-dependencies的插件：maven-help-plugin

maven-help-plugin：

<plugin>
  <artifactId>maven-help-plugin</artifactId>
  <executions>
    <execution>
      <id>generate-effective-dependencies-pom</id>
      <phase>generate-resources</phase>
      <goals>
        <goal>effective-pom</goal>
      </goals>
      <configuration>
        <output>${project.build.directory}/effective-pom.xml</output>
      </configuration>
    </execution>
  </executions>
  <inherited>false</inherited>
</plugin>

新增的插件：gmavenplus-plugin、build-helper-maven-plugin

gmavenplus-plugin：

<plugin>
  <groupId>org.codehaus.gmavenplus</groupId>
  <artifactId>gmavenplus-plugin</artifactId>
  <version>1.1</version>
  <executions>
    <execution>
      <goals>
        <goal>execute</goal>
      </goals>
      <phase>test</phase>
    </execution>
  </executions>
  <configuration>
    <scripts>
      <script>file:///${project.basedir}/src/main/groovyScripts/generateBomPropertiesFile.groovy</script>
    </scripts>
  </configuration>
  <dependencies>
    <dependency>
      <groupId>org.codehaus.groovy</groupId>
      <artifactId>groovy-all</artifactId>
      <version>2.3.0</version>
    </dependency>
  </dependencies>
  <inherited>false</inherited>
</plugin>

build-helper-maven-plugin：

<plugin>
  <groupId>org.codehaus.mojo</groupId>
  <artifactId>build-helper-maven-plugin</artifactId>
  <executions>
    <execution>
      <id>attach-artifacts</id>
      <phase>package</phase>
      <goals>
        <goal>attach-artifact</goal>
      </goals>
      <configuration>
        <artifacts>
          <artifact>
            <file>${project.build.directory}/platform-bom.properties</file>
            <type>properties</type>
          </artifact>
        </artifacts>
      </configuration>
    </execution>
  </executions>
  <inherited>false</inherited>
</plugin>

这样分析之后，对spring-boot-dependencies、spring-boot-starter-parent、io.spring.platform就有了基本的了解了。

这三者最主要的作用还是管理各类依赖的版本控制。

我们完全可以自己做一个pom来管理springboot的依赖引入版本管理，后续文章会展示。

对于pom里各类插件引入的作用，后续也会详细分析。

最终的目的是做到知其然，知其所以然，这样开发起来才会有大局观。