FULL PRODUCT VERSION :
java version "1.6.0"
Java(TM) SE Runtime Environment (build 1.6.0-b105)
Java HotSpot(TM) Client VM (build 1.6.0-b105, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
Linux athene 2.6.17-11-386 #2 Thu Feb 1 19:50:13 UTC 2007 i686 GNU/Linux

A DESCRIPTION OF THE PROBLEM :
NavigableMap map = new TreeMap<K, V>();
Object obj = map.firstKey();

According to the specification of NavigableMap this should return a null.
Instead TreeMap throws a NoSuchElementException.

This breaks the contract for NavigableMap. As far as I can see TreeMap should adhere to the contract of NavigableMap, or not implement it.

This appears to be an error in the specification.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Check the specification.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
map.firstKey() should return a null, as specified.
ACTUAL -
A NoSuchElementException.

REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
Catch the exception.