Maven local repository in settings.xml vs pom.xml

Question

I am new to Maven. I would like to use the following setup:

1) a remote repository to download public artifact

2) a shared local repository for downloaded artifacts which works nicely by adding the following to settings.xml:

<localRepository>C:/m2repo</localRepository>

3) Now I would also like to have a repository for artifacts referenced from a single project, like an old-fashioned "lib" folder.

So I have added the following to the project's pom.xml:

<repository>
  <id>repo</id>
  <name>repo</name> 
  <releases>
    <enabled>true</enabled>
    <checksumPolicy>ignore</checksumPolicy>
  </releases>
  <url>${project.baseUri}repo</url>
</repository>

I have deployed some jars to the "repo" folder, but when I add them as dependencies in pom.xml, they are not resolved. Maven only looks to the shared repository and the remote repository. When I copy the contents of "repo" to the shared "m2repo", it works. Am I missing something or is this setup not possible at all?

score 7 · Answer 1 · edited May 23 '17 at 12:16

Though possible, personally I do not think that it is a good practice to do that. Depending on your usage this post will be helpful: http://blog.sonatype.com/people/2009/02/why-putting-repositories-in-your-poms-is-a-bad-idea. You also want a reproducible and portable project, this question discusses this related topic. Please don't check in those jars into your VCS just for portability sake!

I will try to help if you still insist. To make your model to work, your "repo folder" must follow the structure defined here.

Even though your "repo folder" is a local file structure, Maven will still treat it as if it is a remote repository, just like maven central. This means, whenever you are building your project, Maven will try to download the jars from your "repo folder" to your .m2 repository too:

Downloading: file:/j/my-project/my-local-repo/com/google/guava/guava/14.0.1/guava-14.0.1.pom
Downloaded: file:/j/my-project/my-local-repo/com/google/guava/guava/14.0.1/guava-14.0.1.pom (6 KB at 276.3 KB/sec)
Downloading: http://repo.maven.apache.org/maven2/com/google/google/1/google-1.pom
Downloaded: http://repo.maven.apache.org/maven2/com/google/google/1/google-1.pom (2 KB at 10.4 KB/sec)

You can see that the guava jar will be downloaded from the "repo folder" to my .m2 repository since it is available from my "repo folder".

Actually, for some things and situations it's the perfect solution, and the only one. Think projects that have dependencies that don't exist in any external repository, and need to be distributed to customers who have no access to your company repository server (and yes, I've encountered that more than once). — jwenting, May 28 '19 at 07:24

j_maly · Accepted Answer · 2013-07-13T08:23:56.267

The cause of my problem was the mirroring of repositories in my settings.xml, I have mirroring set to all repositories:

<mirror>
  <mirrorOf>*</mirrorOf>
</mirror>

which I changed to only external repositories:

<mirror>   
  <mirrorOf>external:*</mirrorOf> 
</mirror>

Now my artifacts are found in the "project" repository. However, Maven behaves differently than I expected, as ceilfors writes, the filesystem repository is treated the same as remote repositories - artifacts are copied from there to the local repository, which leads to duplication of jars between the local repository and other filesystem repositories. So I see the setting is not ideal. However, in my case, I still find it the quickiest way to mavenize the project.

Maven local repository in settings.xml vs pom.xml

2 Answers2