I read a number of threads with the same issue, like this one (and all the threads liked in it), but I'm not able to run Maven with the proxy. I tried all possible configurations and I put the same XML content in the default settings and the user one. I got this error:
[ERROR] Plugin org.apache.maven.plugins:maven-clean-plugin:2.5 or one of its dependencies could not be resolved: Failed to read artifact descriptor for org.apache.maven.plugins:maven-clean-plugin:jar:2.5: Could not transfer artifact org.apache.maven.plugins:maven-clean-plugin:pom:2.5 from/to repo.jenkins-ci.org (https://repo.jenkins-ci.org/public/): Error transferring file: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target from https://repo.jenkins-ci.org/public/org/apache/maven/plugins/maven-clean-plugin/2.5/maven-clean-plugin-2.5.pom with proxyInfo ProxyInfo{host='127.0.0.1', userName='null', port=3128, type='http', nonProxyHosts='null'} -> [Help 1]
The unusual thing this is that the username is reported as null even if my XML looks like:
<proxies>
<proxy>
<active>true</active>
<protocol>http</protocol>
<host>MY_HOST</host>
<port>MY_PORT</port>
<username>MY_DOMAIN\USERNAME</username>
</proxy>
</proxies>
The password is missing, but obviously I also tried with it.
