The Collections Framework has been enhanced in the following ways:
Three new language features are targeted at collections: Generics, Enhanced for Loop, and Autoboxing.
Three new interfaces have been added to the framework (two of which are part of java.util.concurrent): Queue, BlockingQueue, and ConcurrentMap.
Two concrete implementations of Queue have been added, as well as one skeletal implementation.
Five blocking queue implementations have been added, and one ConcurrentMap implementation.
Special-purpose Map and Set implementations are provided for use with typesafe enums.
Special-purpose copy-on-write List and Set implementations have been added.
Wrapper implementations are provided to add dynamic type-safety for most collection interfaces.
Several new algorithms are provided for manipulating collections.
Methods are provided to compute hash codes and string representations for arrays.
Refer to the documentation at http://java.sun.com/j2se/1.5.0/docs/guide/collections/index.html.