Answer given:
TreeMap
LinkedList
Explanation given:
The Vector and Hashtable classes were created before the Collection API was developed. Originally these Collection classes were designed to provide syncronization to avoid data corruption. Later versions of the JDK developed the Collections API to provide the developer with classes that allow them to provide their own
thread safety.
I don't know what to think ! (I don't get the significance of the "via all their methods" part of the question)
Perhaps there is an error of the
test engine .
[ January 08, 2002: Message edited by: Salamina Daniel ]