learn java5 annotation

Java Annotation Facility:

    1.a syntax for declaring annotation types

    2.a syntax for annotating declarations

    3.APIs for reading annotations

    4.a class file representation for annotations

    5.an annotation processing tool



	  public @interface Test { }


Annotation Declaration

    1.Annotation type declarations are similar to normal interface declarations   

    2.An at-sign (@) precedes the interface keyword.

    3.Each method declaration defines an element of the annotation type.

    4.Method declarations must not have any parameters or a throws clause.

    5.Return types are restricted to primitives, String, Class, enums, annotations, and arrays of the preceding types.

    6.Methods can have default values.


Annotating Declarations

	   public static void m5() { }

Annotation Processing Tool

    You can write code to process the declarations where declared.


    	 for (Method m : Class.forName(object).getMethods()) {
         if (m.isAnnotationPresent(Test.class)) {               
             Test a = f.getAnnotation(Test.class);
			 System.out.println(m.getName() +" is annotated with value of " +  a.value());



Leave a Comment

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.