This page summarizes the differences between the 1.2 and 1.3 releases
of the Collections Framework, along with a brief rationale for each change.
Convenience Implementations
Added singletonList and singletonMap.
Previously, there was a convenience implementation for singleton Set, but no
corresponding implementation for List and Map.
Added EMPTY_MAP.
Previously, there were constants for the empty Set and List, but no
corresponding constant for Map.
Special-purpose Implementation
Added Map
constuctor for WeakHashMap. The
Map interface dictates that most
Map implementations should have a "copy constructor" that takes a Map
argument. WeakHashMap lacked such a constructor in the 1.2 release.
