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