[TAP5-2749] Incorrect behavior of getIfExists in EntityApplicationStatePersistenceStrategy

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 5.5.0, 5.8.2
• Fix Version/s: 5.8.3
• Component/s: tapestry-jpa
• Assignee: Volker Lamp
• Reporter: Vladimir V. Bychkov
• Created: 08/Mar/23 14:32
• Updated: 07/Jul/23 06:53
• Resolved: 23/Apr/23 22:19

Description

Error description
Test project demonstrates an error which was added during optimization TAP5-2478.
Methods get and getIfExists in ApplicationStateManager work different for JPA-Entities: first works correct, second gives ClassCastException.

Reason
By invoking ApplicationStateManager.set method EntityApplicationStatePersistenceStrategy.set is used, which transforms instanceof Entity-class to instance of PersistedEntity Class.
By Invoking ApplicationStateManager.get method EntityApplicationStatePersistenceStrategy.get is used, which transforms instanceof PersistedEntity Class back to Entity-class. Therefore this code works correct.
By Invoking ApplicationStateManager.getIfExists method SessionApplicationStatePersistenceStrategy.getIfExists is used (SessionApplicationStatePersistenceStrategy is a superclass for EntityApplicationStatePersistenceStrategy), which casts instanceof PersistedEntity Class to Entity-class. This is incorrect and gives ClassCastException in this code.

In other words, get makes back transformation, getIfExists - not. This is the root of problem.

Fix proposal
The best solution IMHO will be restore getIfExists in EntityApplicationStatePersistenceStrategy, may be with some optimizations from TAP5-2478.

Issue Links

• is caused by: TAP5-2478 Create getIfExists in SessionApplicationStatePersistenceStrategy