maven里面pom文件的各标签介绍

       由于maven在工作中经常使用，但是平时要记的知识点有点多，偶尔回头来看一些东西难免忘记，特此整理一篇笔记，方便大家搜索查询，也方便自己以后查询！

后续碰见其他的标签也会进行更新！

      maven的pom文件中存在引入依赖、声明、继承；引入依赖的时候首先去本地仓库找，找不到再去配置的其他仓库找！

 1.modelVersion

 <modelVersion>4.0.0</modelVersion><!--描述这个POM文件是遵从哪个版本的项目描述符。-->

   2.parent

  <parent><!--父级依赖，继承-->
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

  3.dependencies

 <dependencies><!--引入依赖-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>
    </dependencies>

4.dependencyManagement

 <!--声明依赖，如果dependencies中没有声明版本就会来这里面找-->
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Finchley.BUILD-SNAPSHOT</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

5.repositories

<!--   &lt;!&ndash;相当于配置远程仓库&ndash;&gt;
    <repositories>
        <repository>
            <id>spring-snapshots</id>
            <name>Spring Snapshots</name>
            <url>https://repo.spring.io/libs-snapshot</url>
            &lt;!&ndash;是否自动更新&ndash;&gt;
            <snapshots>
                <enabled>true</enabled>
            </snapshots>
        </repository>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/libs-milestone</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
        <repository>
            <id>spring-releases</id>
            <name>Spring Releases</name>
            <url>https://repo.spring.io/libs-release</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>

6.properties

 <properties><!--定义的标签属性可以在其他地方读取-->
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <start-class>eureka.EurekaApplication</start-class>
        <java.version>1.8</java.version>
        <docker.image.prefix2></docker.image.prefix2>
    </properties>

7.pluginRepositories

  <!–插件仓库–>
    <pluginRepositories>
        <pluginRepository>
            <id>spring-snapshots</id>
            <name>Spring Snapshots</name>
            <url>https://repo.spring.io/libs-snapshot-local</url>
            <snapshots>
                <enabled>true</enabled>
            </snapshots>
        </pluginRepository>
        <pluginRepository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/libs-milestone-local</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </pluginRepository>
    </pluginRepositories>-->

 8.配置jdk版本

   <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
   </build>