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34 package info.magnolia.i18nsystem.util;
35
36 import com.google.common.base.Predicate;
37 import org.reflections.ReflectionUtils;
38 import java.lang.annotation.Annotation;
39 import java.lang.reflect.AnnotatedElement;
40 import java.lang.reflect.Method;
41 import java.lang.reflect.TypeVariable;
42 import java.util.Set;
43
44
45
46
47
48 public class AnnotationUtils {
49 private static final org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(AnnotationUtils.class);
50
51 public static boolean hasAnnotationOn(AnnotatedElement annotatedElement, final Class<? extends Annotation> annotationType) {
52 if (annotatedElement instanceof Class) {
53 return getAllAnnotationsOfType((Class) annotatedElement, annotationType).size() > 0;
54 } else if (annotatedElement instanceof Method) {
55 return isMethodAnnotatedWith((Method) annotatedElement, annotationType);
56 } else if (annotatedElement instanceof TypeVariable) {
57 log.debug("Looks like we're running on Java 8. Ignoring annotations on TypeVariable, skipping {}.", annotatedElement);
58 return false;
59 } else {
60 throw new IllegalArgumentException("Only supports Class and Method, can't deal with " + annotatedElement + " (" + annotatedElement.getClass() + ")");
61 }
62 }
63
64 public static <A extends Annotation> A getAnnotationOn(Class annotatedElement, final Class<A> annotationType) {
65 final Set<A> allAnnotations = getAllAnnotationsOfType(annotatedElement, annotationType);
66 if (allAnnotations.isEmpty()) {
67 throw new IllegalStateException(annotatedElement + " is not annotated with @" + annotationType.getSimpleName());
68 }
69 if (allAnnotations.size() > 1) {
70
71 throw new IllegalStateException();
72 }
73
74 return allAnnotations.iterator().next();
75 }
76
77 private static <A extends Annotation> Set<A> getAllAnnotationsOfType(Class clazz, Class<A> annotationType) {
78
79 return (Set<A>) ReflectionUtils.getAllAnnotations(clazz, new AnnotationTypePredicate(annotationType));
80 }
81
82
83
84
85 private static boolean isMethodAnnotatedWith(Method method, Class<? extends Annotation> annotation) {
86 final Set<Class<?>> clazzes = ReflectionUtils.getAllSuperTypes(method.getDeclaringClass());
87 for (Class clazz : clazzes) {
88 try {
89 final Method m = clazz.getDeclaredMethod(method.getName(), method.getParameterTypes());
90 if (m.isAnnotationPresent(annotation)) {
91 return true;
92 }
93 } catch (NoSuchMethodException e) {
94 }
95 }
96
97 return false;
98 }
99
100 private static class AnnotationTypePredicate implements Predicate<Annotation> {
101 private final Class<? extends Annotation> annotationType;
102
103 public AnnotationTypePredicate(Class<? extends Annotation> annotationType) {
104 this.annotationType = annotationType;
105 }
106
107 @Override
108 public boolean apply(Annotation input) {
109 return annotationType.isInstance(input);
110 }
111 }
112 }