[FLINK-21676] Ensure that state names are valid identifiers in the StateFun Java SDK

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: statefun-3.0.0
• Component/s: Stateful Functions
• Assignee: Tzu-Li (Gordon) Tai
• Reporter: Tzu-Li (Gordon) Tai
• Created: 09/Mar/21 02:49
• Updated: 10/Mar/21 06:47
• Resolved: 10/Mar/21 06:47

Description

While the Java SDK only access state via state name strings, other SDKs, like the Python SDK, may access state as properties on the storage instance.

To ensure that users can properly access previous state after swapping languages for their functions, we should enforce that specified state names are valid identifiers, following the rules below:

• Must start with either an alphabet letter [a-z] / [A-Z], or an underscore "_".
• Characters other than the first, can be either an alphabet letter [a-z] / [A-Z], a digit [0-9], or an underscore "_".
• Must not contain spaces.