为平面多模块maven项目配置SCM，以便eclipse可以立即检出所有内容

Question

I've been playing a lot with this and can't find a proper way to do it. This is my setup:

/parent
  pom.xml
    <modules>
      <module>../module-1</module>
      ...
      <module>../module-n</module>
    </modules>
    <scm><connection>https://repo/trunk</connection>...</scm>
/module-1
  pom.xml
...
/module-n
  pom.xml

I was expecting eclipse to checkout all sub modules projects when I checkout the parent. Is that possible in a flat project hierarchy?

Answer 1

The give structure implies that your module-1 is on the same level as parent which does not make sense neither in Eclipse nor in Maven. The best is to structure the project like the following:

 +-- parent (pom.xml)
        +-- module-1 (pom.xml)
        +-- module-2 (pom.xml)

With such a structure you can simple checkout the parent and get everything you need to work with. apart from that it will make your pom file in particular the modules part simpler which can done like this:

<modules>
  <module>module-1</module>
  ..
  <module>module-n</module>
</modules>

and your childs simply use the parent like this:

   <parent>
     <groupId>..</groupId>
     <artifactId>..</artifactId>
     <version>...</version>
   </parent>

Answer 2

• If your sub-modules do not live independently of their aggregating project, it is probably better to move to a hierarchical structure, as suggested in @khmarbaise's answer.
• If yours are really independent projects consider handling them as libraries and keep them separate from the aggregator project; this would mean releasing them separately and use your aggregator just to assemble them for release as a war or a zip file.
• If you're somewhat stuck in the middle, because you'd like to be able to use your sub-modules separately, but you're developing all of them at the same time and you're using Subversion for version control you might hook your sub-modules to your aggregator by means of Subversion's externals mechanism. This requires a little more work than having a single, multi-module repository, but it's rather convenient for working with Eclipse. The downside is the fact that as far as I know the Maven Release plugin cannot deal with this configuration.