I intended to use the unpack mojo with the following configuration
to copy files from a JAR somewhere into the src/ hierarchy of another project, if and only if
- the target file does not exist yet or
- the target file is older than the file from the JAR
Unlike the related Ant task UnZip, the mojo does not check the timestamps of the archive entries against the timestamps of the target files. In my case, this leads to the unwanted effect that target files are always overwritten, even if they are newer.
The Plexus UnArchiver has a property overwrite that should be used by the plugin when unpacking files.