I needed it for cxf-wadl2java-plugin originally. But since it is a part of tools the change will be propagated. Arguments are passed through existing plugin parameter <extraargs> with prefix -xjc.
Patch is included.
I also added a test for generating toString with JAXB objects (this required dependency for jaxb2-basics with test scope).
Things already done:
1. Multiple arguments allowed
2. Code passed checkstyle verification
3. Prepared on trunk (2.8.0-SNAPSHOT)
Things to consider to change:
1. Implementation eventually
2. Add additional verification for test to check if toString was really generated
3. Replace dependency to jaxb2-basics with custom plugin (for tests)
I don't know if I have to add it but I provide this code without any warranty and for free. You can use it or change it whatever you like.
But it would be good if you would consider adding it as for now it is impossible to pass jaxb arguments which can be very useful (even mandatory)