Maven与Nexus Repository集成配置问题求助

Hey there, let's work through why your Maven build is still pulling from the central repository instead of your Nexus maven_ub repo. Here are step-by-step checks and fixes to resolve this:

1. Verify Which settings.xml Maven is Actually Using #

Maven prioritizes the user-specific settings file over the global one in most cases. The user settings are located at C:\Users\<YourUsername>\.m2\settings.xml, while you modified the global one at C:\Program Files\apache-maven-3.3.9\conf\settings.xml.

• Run this command to see the effective settings Maven is applying:

  mvn help:effective-settings
  

• Look for the <mirrors> section in the output. If your Nexus mirror isn't listed, Maven is loading a different settings.xml. You can either:
  • Update the user-specific settings.xml with your mirror configuration, or
  • Force Maven to use your modified global settings by running builds with:

    mvn clean install -s "C:\Program Files\apache-maven-3.3.9\conf\settings.xml"
    

2. Confirm Your Nexus Repository Configuration #

Your maven_ub repo needs to be set up correctly to proxy the central repository:

• Log into your Nexus admin panel and check if maven_ub is a Proxy Repository (not a Hosted repository). Hosted repos only store local artifacts and won't pull from central.
• Ensure the proxy repository is configured to point to Maven Central (default URL: https://repo.maven.apache.org/maven2/) and that the repository status shows as Online.
• Test if you can access the repo directly via browser: http://1.2.3.4:8081/repository/maven_ub/ — you should see the repository's directory structure.

3. Adjust the mirrorOf Scope #

Your current <mirrorOf>central</mirrorOf> only mirrors the official central repo. If your project uses other repositories (like Spring's repo, for example), Maven will bypass your Nexus mirror to pull from those.

• To mirror all repositories (a common setup for internal Nexus usage), change the value to:

  <mirrorOf>*</mirrorOf>
  

  Note: If you have local or specialized repos that shouldn't be mirrored, you can exclude them with syntax like <mirrorOf>*,!local-repo</mirrorOf>.

4. Clear Maven Local Repository Cache #

Maven might be using cached dependencies from your local repo instead of fetching from Nexus.

• Delete the relevant dependency folders in C:\Users\<YourUsername>\.m2\repository, or
• Run your build with the -U flag to force dependency updates:

  mvn clean install -U
  

5. Check for Repository Configurations in Your Project's pom.xml #

If your project's pom.xml includes explicit <repositories> or <pluginRepositories> sections, these can override the mirror settings in settings.xml.

• Open your project's pom.xml and look for these sections. If they exist, either:
  • Remove them to rely on your Nexus mirror, or
  • Ensure your mirrorOf configuration covers these repos (using <mirrorOf>*</mirrorOf> as mentioned earlier).

内容的提问来源于stack exchange，提问作者Shalika