No plugin found for prefix 'dependency' in the current project and in the plugin groups

在研究SpringBoot2.2.5启动原理的时候，下载SpringApplication.class类文档的时候，发现报错！出现错误：

解决办法

在项目pom.xml目录下执行

mvn dependency:resolve -Dclassifier=sources

正常来说，这么就可以解决的，但是我在运行的时候出现了一个bug

No plugin found for prefix 'dependency' in the current project and in the plugin groups [org.apache.maven.plugins, org.codehaus.mojo] available from the repositories [local (C:
\ProgramFiles\maven\apache-maven-3.6.1-bin\MavenRepository), nexus-aliyun (http://maven.aliyun.com/nexus/content/groups/public)] -> [Help 1]

通过https://stackoverflow.com/questions/48939973/maven-no-plugin-found-for-prefix-dependency-in-the-current-project-and-in-the 提示，解决问题，

在pom.xml文件中添加：

<plugins>
  <plugin>
    <groupId>org.apache.maven.plugins</groupId> 
    <artifactId>maven-dependency-plugin</artifactId> 
    <version>3.0.2</version> 
    <executions> 
      <execution> 
        <id>copy-dependencies</id> 
        <phase>package</phase> 
        <goals> 
          <goal>copy-dependencies</goal> 
        </goals> 
        <configuration> 
          <!-- configure the plugin here --> 
        </configuration> 
      </execution> 
    </executions> 
  </plugin> 
</plugins>