The Artifactory REST API has an "Archive Entry Download" capability (https://www.jfrog.com/confluence/display/JFROG/Artifactory+REST+API#ArtifactoryRESTAPI-ArchiveEntryDownload), making it possible to download files within an archive (jar,tgz, etc...). However it seems like you must know the path inside of the archive in order to do this.
curl -n 'https://artifactory-host/repo/path/to/archive.tgz!/path/within/archive.txt'
# Gives contents of /path/within/archive.txt
curl -n 'https://artifactory-host/repo/path/to/archive.tgz!/path'
# gives the following:
{
"errors" : [ {
"status" : 404,
"message" : "{\"error\":\"Expected a folder but found a file, at: repo:path/to/archive.tgz\"}"
} ]
I'm not aware of a way to get a listing of what is in an archive, however there must be a way, given that in the web UI you can expand the file tree of an archive as though it were just another directory.
Which endpoint is being used by the web UI to get that listing?