Helper methods for working with {@link Annotation} instances.
- * + * *This contains various utility methods that make working with annotations simpler.
- * + * *#ThreadSafe#
- * + * * @since 3.0 * @version $Id$ */ @@ -91,7 +91,7 @@ public class AnnotationUtils { /** *{@code AnnotationUtils} instances should NOT be constructed in * standard programming. Instead, the class should be used statically.
- * + * *This constructor is public to permit tools that require a JavaBean * instance to operate.
*/ @@ -101,11 +101,11 @@ public class AnnotationUtils { //----------------------------------------------------------------------- /** *Checks if two annotations are equal.
- * + * *Dynamically created {@link Annotation} instances are always proxy * objects which cannot be depended upon to know how to implement * {@link Annotation#equals(Object)} correctly.
- * + * * @param a1 the first Annotation to compare, null returns false unless both are null * @param a2 the second Annotation to compare, null returns false unless both are null * @return true if the two annotations are equal or both null @@ -145,14 +145,14 @@ public class AnnotationUtils { /** *Generate a hash code for the given annotation.
- * + * *Dynamically created {@link Annotation} instances are always proxy * objects which cannot be depended upon to know how to implement * {@link Annotation#hashCode()} correctly.
- * + * * @param a the Annotation for a hash code calculation is desired, not null * @return the calculated hash code - * @throws RuntimeException if IllegalAccessException or InvocationTargetException + * @throws RuntimeException if IllegalAccessException or InvocationTargetException * or any other Exception is thrown during annotation access * @throws IllegalStateException if an annotation method invocation returns {@code null} */ @@ -179,7 +179,7 @@ public class AnnotationUtils { /** *Generate a string representation of an Annotation, as suggested by * {@link Annotation#toString()}.
- * + * * @param a the annotation of which a string representation is desired * @return the standard string representation of an annotation, not null */ @@ -202,11 +202,11 @@ public class AnnotationUtils { /** *Checks if the specified type is permitted as an annotation member.
- * + * *The Java language specification only permits certain types to be used * in annotations. These include {@link String}, {@link Class}, primitive types, * {@link Annotation}, {@link Enum}, and arrays of these types.
- * + * * @param type the type to check, null returns false * @return true if the type is a valid type to use in an annotation */ @@ -222,6 +222,13 @@ public class AnnotationUtils { } //besides modularity, this has the advantage of autoboxing primitives: + /** + * Helper method for generating a hash code for a member of an annotation. + * + * @param name the name of the member + * @param the value of the member + * @return a hash code for this member + */ private static int hashMember(String name, Object value) { int part1 = name.hashCode() * 127; if (value.getClass().isArray()) { @@ -233,6 +240,16 @@ public class AnnotationUtils { return part1 ^ value.hashCode(); } + /** + * Helper method for checking whether two objects of the given type are + * equal. This method is used to compare the parameters of two annotation + * instances. + * + * @param type the type of the objects to be compared + * @param o1 the first object + * @param o2 the second object + * @return a flag whether these objects are equal + */ private static boolean memberEquals(Class type, Object o1, Object o2) { if (o1 == o2) { return true; @@ -249,6 +266,14 @@ public class AnnotationUtils { return o1.equals(o2); } + /** + * Helper method for comparing two objects of an array type. + * + * @param componentType the component type of the array + * @param o1 the first object + * @param o2 the second object + * @return a flag whether these objects are equal + */ private static boolean arrayMemberEquals(Class componentType, Object o1, Object o2) { if (componentType.isAnnotation()) { return annotationArrayMemberEquals((Annotation[]) o1, (Annotation[]) o2); @@ -280,6 +305,13 @@ public class AnnotationUtils { return Arrays.equals((Object[]) o1, (Object[]) o2); } + /** + * Helper method for comparing two arrays of annotations. + * + * @param a1 the first array + * @param a2 the second array + * @return a flag whether these arrays are equal + */ private static boolean annotationArrayMemberEquals(Annotation[] a1, Annotation[] a2) { if (a1.length != a2.length) { return false; @@ -292,6 +324,13 @@ public class AnnotationUtils { return true; } + /** + * Helper method for generating a hash code for an array. + * + * @param componentType the component type of the array + * @param o the array + * @return a hash code for this array + */ private static int arrayMemberHash(Class componentType, Object o) { if (componentType.equals(Byte.TYPE)) { return Arrays.hashCode((byte[]) o);