[DERBY-5910] Document use of Connection.close() with try-with-resources

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 10.9.1.0
• Fix Version/s: 10.8.3.0, 10.9.2.2, 10.10.1.1
• Component/s: Documentation
• Assignee: Camilla Haase
• Reporter: Camilla Haase
• Created: 24/Aug/12 15:09
• Updated: 25/Nov/12 20:14
• Resolved: 18/Oct/12 19:17

Description

The Java SE 7 try-with-resources feature can cause problems with AutoCloseable objects like java.sql.Connection. You must be careful when writing portable code which declares Connections in the initializers of try-with-resources blocks, because Derby raises an exception if you try to close a Connection with uncommitted work in-flight.

Changing Derby's Connection.close() to always commit in-flight work (and not raise an exception) would create backward compatibility issues, but we do not know yet how serious these issues would be, owing to a lack of data.

Rather than change Derby's behavior now, we should document how Derby's Connection.close() behaves and describe the portability issues involved in declaring Derby Connections in try-with-resources initializers.