我们在创建Maven构建的Spring Boot项目时，会自动生成一个Pom.xml的文件
，其中有一段代码如下：
<parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.2.0.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent>它用来提供Maven的的默认依赖，常用的包依赖就可以省略包版本(version)信息,使用该设置，还可以通过自己的属性来覆盖各个依赖项。
我们可以在本地仓库打开它的源码来一探究竟，在我这台电脑上的路径是C:\Users\k8402.m2\repository\org\springframework\boot\spring-boot-starter-parent\2.2.0.RELEASE.spring-boot-starter-parent-2.2.0.RELEASE.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>org.springframework.boot</groupId> <artifactId>spring-boot-dependencies</artifactId> <version>2.2.0.RELEASE</version> <relativePath>../../spring-boot-dependencies</relativePath> </parent> <artifactId>spring-boot-starter-parent</artifactId> <packaging>pom</packaging> <name>Spring Boot Starter Parent</name> <description>Parent pom providing dependency and plugin management for applications built with Maven</description> <url>https://projects.spring.io/spring-boot/#/spring-boot-starter-parent</url> <properties> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> <resource.delimiter>@</resource.delimiter> <maven.compiler.source>${java.version}</maven.compiler.source> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.target>${java.version}</maven.compiler.target> </properties> <build> <resources> <resource> <filtering>true</filtering> <directory>${basedir}/src/main/resources</directory> <includes> <include>**/application*.yml</include> <include>**/application*.yaml</include> <include>**/application*.properties</include> </includes> </resource> <resource> <directory>${basedir}/src/main/resources</directory> <excludes> <exclude>**/application*.yml</exclude> <exclude>**/application*.yaml</exclude> <exclude>**/application*.properties</exclude> </excludes> </resource> </resources> <pluginManagement> <plugins> <plugin> <groupId>org.jetbrains.kotlin</groupId> <artifactId>kotlin-maven-plugin</artifactId> <version>${kotlin.version}</version> <executions> <execution> <id>compile</id> <phase>compile</phase> <goals> <goal>compile</goal> </goals> </execution> <execution> <id>test-compile</id> <phase>test-compile</phase> <goals> <goal>test-compile</goal> </goals> </execution> </executions> <configuration> <jvmTarget>${java.version}</jvmTarget> <javaParameters>true</javaParameters> </configuration> </plugin> <plugin> <artifactId>maven-compiler-plugin</artifactId> <configuration> <parameters>true</parameters> </configuration> </plugin> <plugin> <artifactId>maven-failsafe-plugin</artifactId> <executions> <execution> <goals> <goal>integration-test</goal> <goal>verify</goal> </goals> </execution> </executions> <configuration> <classesDirectory>${project.build.outputDirectory}</classesDirectory> </configuration> </plugin> <plugin> <artifactId>maven-jar-plugin</artifactId> <configuration> <archive> <manifest> <mainClass>${start-class}</mainClass> <addDefaultImplementationEntries>true</addDefaultImplementationEntries> </manifest> </archive> </configuration> </plugin> <plugin> <artifactId>maven-war-plugin</artifactId> <configuration> <archive> <manifest> <mainClass>${start-class}</mainClass> <addDefaultImplementationEntries>true</addDefaultImplementationEntries> </manifest> </archive> </configuration> </plugin> <plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>exec-maven-plugin</artifactId> <configuration> <mainClass>${start-class}</mainClass> </configuration> </plugin> <plugin> <artifactId>maven-resources-plugin</artifactId> <configuration> <delimiters> <delimiter>${resource.delimiter}</delimiter> </delimiters> <useDefaultDelimiters>false</useDefaultDelimiters> </configuration> </plugin> <plugin> <groupId>pl.project13.maven</groupId> <artifactId>git-commit-id-plugin</artifactId> <executions> <execution> <goals> <goal>revision</goal> </goals> </execution> </executions> <configuration> <verbose>true</verbose> <dateFormat>yyyy-MM-dd'T'HH:mm:ssZ</dateFormat> <generateGitPropertiesFile>true</generateGitPropertiesFile> <generateGitPropertiesFilename>${project.build.outputDirectory}/git.properties</generateGitPropertiesFilename> </configuration> </plugin> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <executions> <execution> <id>repackage</id> <goals> <goal>repackage</goal> </goals> </execution> </executions> <configuration> <mainClass>${start-class}</mainClass> </configuration> </plugin> <plugin> <artifactId>maven-shade-plugin</artifactId> <executions> <execution> <phase>package</phase> <goals> <goal>shade</goal> </goals> <configuration> <transformers> <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer"> <resource>META-INF/spring.handlers</resource> </transformer> <transformer implementation="org.springframework.boot.maven.PropertiesMergingResourceTransformer"> <resource>META-INF/spring.factories</resource> </transformer> <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer"> <resource>META-INF/spring.schemas</resource> </transformer> <transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer"/> <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer"> <mainClass>${start-class}</mainClass> </transformer> </transformers> </configuration> </execution> </executions> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <version>2.2.0.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> </plugin> </plugins> </pluginManagement> </build> </project>通过上面的代码可以看出，它继承自spring-boot-dependencies，在这里有基本的依赖信息，以及项目的编码格式和java版本等，最后再来看看源码中指定的spring-boot-dependencies的信息(该文件中代码实在过多，只举例说明)：
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> <version>2.2.0.RELEASE</version> </dependency>在它继承的spring-boot-dependencies里面已经写好了版本，所以我们不需要再声明了。
当然，有可能你并不想从spring-boot-starter-parent来继承，可能你需要使用自己公司所提供的父级，则你可以通过scope=import来保持依赖项：
<dependencyManagement> <dependencies> <dependency> <!-- Import dependency management from Spring Boot --> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-dependencies</artifactId> <version>2.0.2.RELEASE</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement>但这么做之后，就不允许使用属性来覆盖依赖项，有一种解决方法，在Pom.xml中添加如下信息：
<dependencyManagement> <dependencies> <!-- Override Spring Data release train provided by Spring Boot --> <dependency> <groupId>org.springframework.data</groupId> <artifactId>spring-data-releasetrain</artifactId> <version>Fowler-SR2</version> <type>pom</type> <scope>import</scope> </dependency> <!--这是添加项--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-dependencies</artifactId> <version>2.0.2.RELEASE</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement>