dependencyManagement和dependencies之间的区别是什么?
我在Apache Maven网站上看过文档。
在dependencyManagement下定义的依赖项似乎可以在其子模块中使用，而无需指定版本。
例如:
父项目(Pro-par)在dependencyManagement下定义了一个依赖项:
<dependencyManagement>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8</version>
</dependency>
</dependencies>
</dependencyManagement>
然后在Pro-par的子函数中，我可以使用junit:
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
</dependency>
</dependencies>
但是，我想知道是否有必要在父pom中定义junit ?为什么不在需要的模块中直接定义它呢?
有几个答案概述了maven的< dependencies >和<dependencyManagement>标记之间的区别。
但是，下面简要阐述了几点:
<dependencyManagement> allows to consolidate all dependencies (used at child pom level) used across different modules -- clarity, central dependency version management
<dependencyManagement> allows to easily upgrade/downgrade dependencies based on need, in other scenario this needs to be exercised at every child pom level -- consistency
dependencies provided in <dependencies> tag is always imported, while dependencies provided at <dependencyManagement> in parent pom will be imported only if child pom has respective entry in its <dependencies> tag.
用我自己的话来说，你的父项目帮助你提供了两种依赖:
implicit dependencies : all the dependencies defined in the <dependencies> section in your parent-project are inherited by all the child-projects
explicit dependencies : allows you to select, the dependencies to apply in your child-projects. Thus, you use the <dependencyManagement> section, to declare all the dependencies you are going to use in your different child-projects. The most important thing is that, in this section, you define a <version> so that you don't have to declare it again in your child-project.
在我看来，<dependencyManagement>(如果我错了请纠正我)只是通过帮助您集中依赖项的版本而有用。它就像一种辅助功能。
作为最佳实践，您的<dependencyManagement>必须在父项目中，其他项目将继承它。一个典型的例子是通过声明Spring父项目来创建Spring项目。
