java.util.Collections currently provide the following utility methods for creating synchronized wrapper for various collection interfaces:

• synchronizedCollection(Collection<T> c)
• synchronizedList(List<T> list)
• synchronizedMap(Map<K,V> m)
• synchronizedSet(Set<T> s)
• synchronizedSortedMap(SortedMap<K,V> m)
• synchronizedSortedSet(SortedSet<T> s)

Analogously, it also has 6 unmodifiedXXX overloads.

The glaring omission here are the utility methods for NavigableMap<K,V>. It's true that it extends SortedMap, but so does SortedSet extends Set, and Set extends Collection, and Collections have dedicated utility methods for SortedSet and Set. Presumably NavigableMap is a useful abstraction, or else it wouldn't have been there in the first place, and yet there are no utility methods for it.

So the questions are:

• Is there a specific reason why Collections doesn't provide utility methods for NavigableMap?
• How would you write your own synchronized wrapper for NavigableMap?
  • Glancing at the source code for OpenJDK version of Collections.java seems to suggest that this is just a "mechanical" process
    • Is it true that in general you can add synchronized thread-safetiness feature like this?
    • If it's such a mechanical process, can it be automated? (Eclipse plug-in, etc)
    • Is this code repetition necessary, or could it have been avoided by a different OOP design pattern?