If you have a lot of users in your org and have the need to transfer directory/profile photos from a previous platform into Salesforce you will quickly run into a roadblock. We have a need to assist in importing thousands of Customer Community User Photos. There is no way to import the photos in bulk using Data Loader or apex script coding.
There are fields in the User object that have been exposed which are the FullPhotoURL and SmallPhotoURL, but these are read-only and there is no way to set them in apex or data loader. Here is the error from execute anonymous: Field is not writeable: User.FullPhotoUrl
Cloudspokes started a contest years ago to write an app to do this. I found the same-named for-pay app called Chatter Photos Bulk Importer.
I checked github to see if there was anything open-source. I found a project on GitHub built in Java.
A requirement of using this is to package the source files into a single jar file. I decided to use Eclipse since I am familiar with it. I found that packaging in Eclipse is much easier with the following plugin (based on some reviews) so I gave it a try.