jOOQ: Implementing the DSL types

Applies to ✅ Open Source Edition   ✅ Express Edition   ✅ Professional Edition   ✅ Enterprise Edition

Almost the entire jOOQ DSL API as well as the model API should be considered as sealed in the sense of Java 17. In fact, starting from jOOQ 3.16, we have started sealing types and will continue to do so in the near future.

This means, users should never attempt to extend jOOQ via inheritance, unless explicitly stated otherwise. Exceptions to this rule include:

• CustomQueryPart and related types, which are designed to be subclassed.
• Configuration SPIs which are designed to be implemented by users, following a strategy pattern style design.
• Public classes starting with AbstractXYZ (must be extended to be used) or DefaultXYZ (may be extended, but can be used out of the box, too).