Create a ZIP archive with Maven

I followed the answer for how to create a ZIP archive in Maven here: https://stackoverflow.com/a/2514677/1395165 and have a couple of follow-up questions:

ZIP contents to exclude directory:

As in the example I have:

<fileSet>
    <directory>${project.basedir}/src/export</directory>
    <useDefaultExcludes>true</useDefaultExcludes>
</fileSet>

In the ZIP I get

src
  export
     Dir1
     Dir2

but I only want to have

Dir1
Dir2 

in the ZIP. Is that possible?

Output file name

The output file name is created with a .zip extension. Is it possible in Maven to override the extension to something else (say .abc)?