Nexus keeps an index of all the repositories managed by it. The index is maintained as a standard Lucene index. Nexus uses the created index in order to find where the requested artifacts belong, prior to talking to a remote repository.
Apache Lucene is an open source project released under Apache 2.0 License is available at http://lucene.apache.org/.
The following list shows you how to update the index of a given repository:
http://localhost:8081/nexus
and log in as admin
.3.144.97.187