Function versioning in Java

I need to design the architecture of a large Java back-end application. It must expose a large collection of Rest endpoints. The main requirement is that each endpoint should be "versioned". For example: - endpoint http://mysite/myapp/myendpoint/v1 gets officially published - a bugfix/enhancement is requested - the implementation must be done on http://mysite/myapp/myendpoint/v2, while v1 must continue to stay available forever, even if bugged

How can I satisfy this requirement in the most clean/easy/maintenable way?