[LANG-360] Why does appendIdentityToString return null?

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.4
• Assignee: Unassigned
• Reporter: Jörg Gottschling
• Created: 21/Oct/07 12:22
• Updated: 12/Nov/07 22:54
• Resolved: 12/Nov/07 22:54

Description

ObjectUtils is designed to handle null imputs gracefully. But ObjectUtils.appendIdentityToString does not. It returns null unnessecary if you pass null als second parameter (the object to get the identity from). For example appendIdentityToString(new StringBuffer(), null) will return null! Which is an uncommen behaviour. Think about code like this:

ObjectUtils.appendIdentityToString(buffer, param1)
.appendIdentityToString(buffer, param2)
.appendIdentityToString(buffer, param3);

This will cause an NPE if param1 or param2 ist null. There may be other code where a NPE will not happen, but the code is used for debugging and there will be an unexpected or wrong output.

So you shoul return the StringBuffer which is passed in or a new one if null. The harder question is what to do with the object. I think we should append "null" to the StringBuffer, because this is what I would expect and what the passed reference is.