[CAY-323] Cayenne thinks array types are modified across request/response cycles

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.1 [LEGACY]
• Fix Version/s: 1.1 [LEGACY]
• Component/s: Core Library
• Environment: All OS + Servlets
• Assignee: Michael Gentry
• Reporter: Michael Gentry
• Created: 29/May/05 17:00
• Updated: 29/Sep/05 00:00
• Resolved: 16/Jun/05 03:10

Description

When Cayenne is used in a web-based application, such as Tapestry, and DataObjects are serialized in the session between request/response loops, any array data types are reconstituted to new memory locations when deserialzed. Because the equals() method in Java compares pointers for arrays instead of comparing the contents of the array, Cayenne believes the array attribute has been modified even if the contents haven't changed (equivalent array values are considered modified). This will cause Cayenne to potentially issue unneeded UPDATE statements or to include array attributes which haven't changed (even though other attributes changed in that row).

This problem is particularly noticeable when your primary keys are byte arrays.