Allow for checking field level annotations from DiffNode (getFieldAnnotations() functions added, similarly to getPropertyAnnotations()).

Author: Gabor Nagy

src/main/java/de/danielbechler/diff/access/PropertyAwareAccessor.java

@@ -26,6 +26,10 @@ public interface PropertyAwareAccessor extends TypeAwareAccessor, CategoryAware,
 {
 	String getPropertyName();
 
+	Set<Annotation> getFieldAnnotations();
+
+	<T extends Annotation> T getFieldAnnotation(Class<T> annotationClass);
+
 	Set<Annotation> getReadMethodAnnotations();
 
 	<T extends Annotation> T getReadMethodAnnotation(Class<T> annotationClass);

src/main/java/de/danielbechler/diff/introspection/PropertyAccessor.java

@@ -83,6 +83,44 @@ public String getPropertyName()
 		return this.propertyName;
 	}
 
+	/**
+	 * Private function to allow looking for the field recursivery up the superclasses.
+	 *
+	 * @param clazz
+	 * @return
+	 */
+	private Set<Annotation> getFieldAnnotations(final Class<?> clazz) {
+		try {
+			return new LinkedHashSet<Annotation>(asList(clazz.getDeclaredField(propertyName).getAnnotations()));
+		} catch (NoSuchFieldException e) {
+			if (clazz.getSuperclass() != null) {
+				return getFieldAnnotations(clazz.getSuperclass());
+			} else {
+				logger.debug("Cannot find propertyName: {}, declaring class: {}", propertyName, clazz);
+				return new LinkedHashSet<Annotation>(0);
+			}
+		}
+	}
+
+	/**
+	 * @return The annotations of the field.
+	 */
+	public Set<Annotation> getFieldAnnotations() {
+		return getFieldAnnotations(readMethod.getDeclaringClass());
+	}
+
+	public <T extends Annotation> T getFieldAnnotation(final Class<T> annotationClass) {
+		final Set<? extends Annotation> annotations = getFieldAnnotations();
+		assert (annotations != null) : "Something is wrong here. " +
+				"The contract of getReadAnnotations() guarantees a non-null return value.";
+		for (final Annotation annotation : annotations) {
+			if (annotationClass.isAssignableFrom(annotation.annotationType())) {
+				return annotationClass.cast(annotation);
+			}
+		}
+		return null;
+	}
+
 	/**
 	 * @return The annotations of the getter used to access this property.
 	 */

src/main/java/de/danielbechler/diff/node/DiffNode.java

@@ -443,6 +443,29 @@ public final void visitParents(final Visitor visitor)
 		}
 	}
 
+	/**
+	 * If this node represents a bean property this method returns all annotations of its field.
+	 *
+	 * @return A set of annotations of this nodes property field or an empty set.
+	 */
+	public Set<Annotation> getFieldAnnotations()
+	{
+		if (accessor instanceof PropertyAwareAccessor)
+		{
+			return unmodifiableSet(((PropertyAwareAccessor) accessor).getFieldAnnotations());
+		}
+		return unmodifiableSet(Collections.<Annotation>emptySet());
+	}
+
+	public <T extends Annotation> T getFieldAnnotation(final Class<T> annotationClass)
+	{
+		if (accessor instanceof PropertyAwareAccessor)
+		{
+			return ((PropertyAwareAccessor) accessor).getFieldAnnotation(annotationClass);
+		}
+		return null;
+	}
+
 	/**
 	 * If this node represents a bean property this method returns all annotations of its getter.
 	 *