Java 6.0 New Collection APIs an Overview

Java 6.0 New Collection APIs an Overview
The following are the new collection APIs introduced in Java 6.0. I listes them as Interfaces and classes.

• New Interfaces

1. Deque
2. BlockingDeque
3. NavigableSet
4. NavigableMap

• New Classes

1. ArrayDeque
2. LinkedBlockingDeque
3. ConcurrentSkipListSet
4. ConcurrentSkipListMap
5. AbstractMap.SimpleEntry
6. AbstractMap.SimpleImmutableEntry

• Updated Classes in Java 6.0

1. LinkedList
2. TreeSet
3. TreeMap
4. Collections

How can I force garbage collection to take place???

You can't force it but you call System.gc(), which is a "hint" to the runtime engine that now might be a good time to run the GC. But garbage collection using this method is not guaranteed to be done immediately.