The Java Programming Language is a general-purpose, concurrent, strongly typed,
class-based object-oriented language. It is normally compiled to the
bytecode instruction set and binary format defined in the Java Virtual Machine
Enhancements in JDK 5
This long-awaited enhancement to the type system allows a
type or method to operate on objects of various types while providing
compile-time type safety. It adds compile-time type safety to the
Collections Framework and eliminates the drudgery of casting.
See the Generics Tutorial.
Enhanced for Loop -
This new language construct eliminates the drudgery
and error-proneness of iterators and index variables when iterating over
collections and arrays.
This facility eliminates the drudgery of manual
conversion between primitive types (such as int) and wrapper types (such
Typesafe Enums -
This flexible object-oriented enumerated type facility
allows you to create enumerated types with arbitrary methods and
fields. It provides all the benefits of the Typesafe Enum pattern
("Effective Java," Item 21) without the verbosity and the error-proneness.
This facility eliminates the need for manually boxing up
argument lists into an array when invoking methods that accept
variable-length argument lists.
Static Import -
This facility lets you avoid qualifying static members
with class names without the shortcomings of the "Constant Interface
Annotations (Metadata) -
This language feature lets you avoid writing boilerplate code
under many circumstances 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. Also it eliminates the need for
maintaining "side files" that must be kept up to date with changes in
source files. Instead the information can be maintained in the
source file. (JSR 175)
NOTE: The @Deprecated annotation provides a way
to deprecate program elements.
See How and When To Deprecate APIs.
JSR14: Adding Generic Types to the Java Programming Language
Assertion Facility -
Assertions are boolean expressions that the programmer believes to be
true concerning the state of a computer program. For example, after
sorting a list, the programmer might assert that the list is in ascending
order. Evaluating assertions at runtime to confirm their validity is
one of the most powerful tools for improving code quality, as it quickly
uncovers the programmer's misconceptions concerning a program's behavior.