Problem getting maven plugin from jfrog artifactory - maven

Question

I'm trying to get an old maven project connected to private artifactory to download plugins when building. I'm sitting in a coporate network (using vpn), using a jfrog artifactory.
"mvn clean install -U" returns:
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Build Order:
[INFO]
[INFO] ProjektYXZ - parent POM [pom]
[INFO] ProjektYXZ - main POM [pom]
[INFO]
[INFO] ---------------------< com.*:mvn-project >----------------------
[INFO] Building ProjektYXZ - parent POM 1.14.0-SNAPSHOT [1/2]
[INFO] --------------------------------[ pom ]---------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) # mvn-project ---
[INFO] Deleting **mvn-project\target
[INFO]
[INFO] >>> maven-source-plugin:3.0.1:jar (attach-sources) > generate-sources # mvn-project >>>
[INFO]
[INFO] <<< maven-source-plugin:3.0.1:jar (attach-sources) < generate-sources # mvn-project <<<
[INFO]
[INFO]
[INFO] --- maven-source-plugin:3.0.1:jar (attach-sources) # mvn-project ---
[INFO]
[INFO] --- maven-javadoc-plugin:3.0.1:jar (attach-javadocs) # mvn-project ---
[INFO] Not executing Javadoc as the project is not a Java classpath-capable package
[INFO]
[INFO] --- maven-checkstyle-plugin:3.0.0:check (default) # mvn-project ---
[INFO]
[INFO] >>> spotbugs-maven-plugin:3.1.11:check (default) > :spotbugs # mvn-project >>>
[INFO]
[INFO] --- spotbugs-maven-plugin:3.1.11:spotbugs (spotbugs) # mvn-project ---
[INFO]
[INFO] <<< spotbugs-maven-plugin:3.1.11:check (default) < :spotbugs # mvn-project <<<
[INFO]
[INFO]
[INFO] --- spotbugs-maven-plugin:3.1.11:check (default) # mvn-project ---
[INFO]
[INFO] >>> maven-pmd-plugin:3.11.0:check (default) > :pmd # mvn-project >>>
[INFO]
[INFO] --- maven-pmd-plugin:3.11.0:pmd (pmd) # mvn-project ---
[INFO]
[INFO] <<< maven-pmd-plugin:3.11.0:check (default) < :pmd # mvn-project <<<
[INFO]
[INFO]
[INFO] --- maven-pmd-plugin:3.11.0:check (default) # mvn-project ---
[INFO]
[INFO] --- plugin:1.4.1:enforce (default) # mvn-project ---
Downloading from central-mirror: https://artifactory.*.de/artifactory/maven/**/*-1.0.2.pom
Downloading from company-releases: https://artifactory.**.de/artifactory/**/1.0.2/*-1.0.2.pom
[WARNING] The POM for com.**:jar:1.0.2 is missing, no dependency information available
Downloading from central-mirror: https://artifactory.**.de/artifactory/maven/**/*-1.0.2.jar
Downloading from company-releases: https://artifactory.**.de/artifactory/**/*-1.0.2.jar
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary for ProjektYXZ - main POM 1.14.0-SNAPSHOT:
[INFO]
[INFO] ProjektYXZ - parent POM .................................. FAILURE [ 7.645 s]
[INFO] ProjektYXZ - main POM .................................... SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 7.826 s
[INFO] Finished at: 2022-04-12T10:18:02+02:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:plugin:1.4.1:enforce (default) on project mvn-project: Execution default of goal org.apache.maven.plugins:plugin:1.4.1:enforce failed: Plugin org.apache.maven.plugins:plugin:1.4.1 or one of its dependencies could not be resolved: Could not find artifact com.**:jar:1.0.2 in central-mirror (https://artifactory.**.de/artifactory/maven) -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginResolutionException
in the line:
Downloading from company-releases: https://artifactory.**.de/artifactory/**/1.0.2/*-1.0.2.pom
maven looks at the correct place. I'm able to download it with curl:
curl -u username:password -X GET "https://artifactory.**.de/artifactory/**/1.0.2/*-1.0.2.pom"
but if I paste that path into Chrome, I get an 404 Error.
I also configured the settings.xml in my C:/Users/Username/.m2/ folder:
<server>
<id>company-releases</id>
<username>my_username</username>
<password>my_password</password>
</server>
I also checked the possible errors of the Link shown at the bottom of the log, but as I'm able to "curl" it these don't seem to be the reasons. Currently I'm out of ideas. I hope you can help me :) Please tell me if you need to see additional sources.

Answer 1

okay, the solution was to set preemptive authentification in settings.xml:
for example:
<server>
<username>*****</username>
<password>*****</password>
<id>central</id>
<configuration>
<httpConfiguration>
<all>
<usePreemptive>true</usePreemptive>
</all>
</httpConfiguration>
</configuration>
</server>
Explanation: maven first tries to request without authentification. If the Repo is private (this means that without authentification, artifacts are hidden), jfrog artifactory responses with 404 instead of unauthenticated. After 404 maven doesn't try again, but sees it as failed.
For more details see: https://jfrog.com/knowledge-base/why-does-my-maven-builds-are-failing-with-a-404-error-when-hide-existence-of-unauthorized-resources-is-enabled/