Ok. My last post ! I found the solution. You have to put it in the pom file of
the module using implementation dependency :
<plugins>
<plugin>
<groupId>org.apache.netbeans.utilities</groupId>
<artifactId>nbm-maven-plugin</artifactId>
<extensions>true</extensions>
<configuration>
<publicPackages>
<publicPackage>testmodule</publicPackage>
</publicPackages>
<moduleDependencies>
<dependency>
<id>org.netbeans.modules:org-netbeans-core-windows</id>
<type>impl</type>
</dependency>
</moduleDependencies>
</configuration>
</plugin>
</plugins>
…..
<dependencies>
…
<dependency>
<groupId>org.netbeans.modules</groupId>
<artifactId>org-netbeans-core-windows</artifactId>
<version>${netbeans.version}</version>
</dependency>
</dependencies>
And its ok : you have access to classes inside core-windows module.
Thx for your help.