使用Maven Central作为辅助存储库

Question

My organization hosts its own maven repository (JFrog) and all dev machines are already configured to always look into the enterprise maven repository for all Java jars.

Now sometimes I am learning new technology on my own and the jar download will sometimes fail because the enterprise maven central does not have those jars

[ERROR] Failed to execute goal on project JooqTest: Could not resolve 
dependencies for project com.abhi:JooqTest:jar:1.0-SNAPSHOT: The following 
artifacts could not be resolved: org.jooq:jooq:jar:3.7.1, org.jooq:jooq-
meta:jar:3.7.1, org.jooq:jooq-codegen:jar:3.7.1: Failure to find 
org.jooq:jooq:jar:3.7.1 in http://artifactory.foo.com/artifactory/all-repos was 
cached in the local repository, resolution will not be reattempted until the 
update interval of foo-artifactory-as-mirror has elapsed or updates are forced -> 
[Help 1]

Can I configure Maven on my machine so it will first look for jars in the organization Maven repository, and if it doesn't find it there, then look into Maven central?

Answer 1

The most desirable outcome would likely be to have them add any other repository server as a proxied server.

From the jfrog page:

Overview
In corporate environments it is often required to go through a proxy server to access remote resources.
Artifactory supports several types of network proxy including NTLMv2.

This is how we have our work environment and build scripts setup which keeps our build script clean and only have a single remote repo listed.

Answer 2

I bet your current settings.xml (either under MVN_DIR/conf , or under your HOME/.m2 ) has setup your enterprise repo as mirror of central.

Normally, assuming you have internet connection, you can add extra remote repositories in your settings.xml by: (copied from https://maven.apache.org/settings.html )

  <profiles>
    <profile>
      ...
      <repositories>
        <repository>
          <id>codehausSnapshots</id>
          <name>Codehaus Snapshots</name>
          <releases>
            <enabled>false</enabled>
            <updatePolicy>always</updatePolicy>
            <checksumPolicy>warn</checksumPolicy>
          </releases>
          <snapshots>
            <enabled>true</enabled>
            <updatePolicy>never</updatePolicy>
            <checksumPolicy>fail</checksumPolicy>
          </snapshots>
          <url>http://snapshots.maven.codehaus.org/maven2</url>
          <layout>default</layout>
        </repository>
      </repositories>
      <pluginRepositories>
        ...
      </pluginRepositories>
      ...
    </profile>
  </profiles>

You may also want to setup proxy if your company require you to connect to internet thru proxy. Related info can be found in above-mentioned URL

Answer 3

If you are desperate and can't get your 'enterprise admin' to configure what you need on the company-wide repo for whatever reason, you could try running your own Maven repository proxy (eg Nexus, Artifactory) on your own machine (or localized to your team) that proxies both Central and your company-wide repo. Then point your settings.xml to your local repo proxy instead of the company-wide one. You might want to do this in a profile so that you can switch between the standard corporate configuration and your proxy easily.

This assumes that you can download JARs from central, and are not blocked by corporate proxy server, etc.

A better situation would be to have a talk with your repo manager and negotiate, perhaps get an 'experimentation' repo that proxies central, and only do the personal proxy thing if absolutely necessary.