I have implemented the XEP-0153: vCard-Based Avatars feature based on Smack 4.18 library release. It also provides the persistent storage support for avatar; and VCard auto-download option. Attached is the source.
Smack Development Team: You are welcome to include this feature in your future Smack library release.
avatar.zip (14878 Bytes)
Thanks for your contribution.
Your contribution would be easier to review if it was presented as an unified diff patch. Or as a github pull request.
Also note that the merge window for Smack 4.2 closes by the end of the year. Everything included in Smack after that will not make it into 4.2.
All the files created are all new and I have placed under the proposed Smack sub-directory i.e.:
org.jivesoftware.smackx.avatar
The zip is created with this directory structure layout. You need only to extract all the files into this sub-directory and thing should work.
However your team may want to review if the proposed sub-directory structure is OK for your release and you may want to relocate if necessary. Actually I am not familiar with github pull request and never attempt before. That is reason I did not do it via pull request.
Note: The source is developed and used in aTalk, an android xmpp client. The application can be downloaded from the following link if you would like to try.
http://atalk.sytes.net/releases/atalk-android/aTalk-release.apk