How to setup circular reference in maven modules? - maven

Question

I have this problem with building a maven project...
A mvn project parent is set like this:
<groupId>com.company.system.ping</groupId>
<artifactId>system-ping</artifactId>
<name>system-ping</name>
<parent>
<artifactId>parent_lvl_1</artifactId>
<groupId>com.company.system</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
Then I look for said parent's POM and find this:
<groupId>com.company.system</groupId>
<artifactId>parent_lvl_1</artifactId>
<packaging>pom</packaging>
<name>_proj_test</name>
<version>1.0-SNAPSHOT</version>
<parent>
<artifactId>parent_lvl_0</artifactId>
<groupId>com.company</groupId>
<version>1</version>
</parent>
I finally look at the first parent and see this:
<groupId>com.company</groupId>
<artifactId>parent_lvl_0</artifactId>
<packaging>pom</packaging>
<name>_main</name>
<version>1</version>
<description>The whole Projects</description>
Now I check the modules:
<modules>
<module>../_proj_test</module>
...
</modules>
The first parent module is referencing a child! So when I try
mvn install
on '_main' I get this:
[ERROR] The project com.company.system:_proj_test:1.0-SNAPSHOT (C:\...\pom.xml) has 1 error
[ERROR] Non-resolvable parent POM: The repository system is offline but the artifact com.company:_main:pom:1 is not available in the local repository. and 'parent.relativePath' points at wrong local POM # line 4, column 10 -> [Help 2]
[ERROR]
I translate this to: you parent requieres a module which requires you back. If I comment out everything in modules I can install everything correctly but this is NOT OK for me! How can I build the parent without building the module dependencies?
Thank you!

Answer 1

The config looks very weird to me, mainly because your '_proj_test' which is a child for '_main' is located on the same level.
How can I build the parent without building the module dependencies?
Try mvn -N install.
As for the project structure, I'd do it in such a way:
1) $basedir with '_main' pom.xml which should contain this
<modules>
<module>_proj_test</module>
</modules>
2) $basedir/_proj_test with '_proj_test' pom.xml which should contain this
<modules>
<module>system-ping</module>
</modules>
3) $basedir/_proj_test/system-ping with 'system-ping' pom.xml (with correct groupId of parent - com.company.system instead of com.company)