Maven Build issues: Cannot access nexus in offline mode and the artifact is not downloaded
<p>We are facing an issue with the Maven build. We have setup proxy in eclipse, got maven installed and all the required settings completed. But everytime we try to build it we are getting following exception:</p>

<p><strong>Project build error: Unresolveable build extension: Plugin org.sonatype.plugins:nexus-staging-maven-plugin:1.4.8 or one of its dependencies could not be resolved: The following artifacts could not be resolved</strong> 
<strong>Cannot access nexus in offline mode and the artifact org.sonatype.plugins:nexus-staging-maven-plugin:jar:1.4.8 has not been downloaded from it before.</strong></p>

<p>We have set all the dependencies. One of the dependencies shows an message:
Offline / Missing artifact com.xxxxx.xxxx:jar:0.0.2-SNAPSHOT</p>

<p>Why do we get this issue and how to resolve it?</p>