Java 1.5 is an alpha early access.
http://java.sun.com/developer/earlyA...2sdk150_alpha/
A snippet of new features as taken from
http://java.sun.com/features/2003/05/bloch_qa.html. :
Generics - Provides compile-time type safety for collections and eliminates the drudgery of casting.
Enhanced for loop - Eliminates the drudgery and error-proneness of iterators.
Autoboxing/unboxing - Eliminates the drudgery of manual conversion between primitive types (such as int) and wrapper types (such as Integer).
Typesafe enums - Provides all the well-known benefits of the Typesafe Enum pattern (Effective Java, Item 21) without the verbosity and the error-proneness.
Static import - Lets you avoid qualifying static members with class names, without the shortcomings of the Constant Interface antipattern (Effective Java, Item 17).
Metadata - Lets you avoid writing boilerplate code, by enabling tools to generate it from annotations in the source code. This leads to a "declarative" programming style where the programmer says what should be done and tools emit the code to do it.