Java Annotations

• provides data about a program but do not directly affect the program semantics


• defined similar to interface
  @interface Author {
  String author();
  String date();
  String[] reviewers(); // Note use of array
  }


• sample use:
  @Author(
  name = "Benjamin Franklin",
  date = "3/27/2003",
  reviewers = {"Alice", "Bob", "Cindy"} // Note array notation
  )
  class MyClass() { }

3 Predefined Annotation Types:
1) @Deprecated - should also be documented using the Javadoc @deprecated tag
/**
* @deprecated
* explanation of why it was deprecated
*/
@Deprecated

2) @Override

3) @SuppressWarnings
@SuppressWarnings("deprecation") //deprecation warning - suppressed
@SuppressWarnings({"unchecked", "deprecation"}) // legacy code & deprecation warning - suppressed

Detailed explanation here: http://java.sun.com/j2se/1.5.0/docs/guide/language/annotations.html