1 files changed, 37 insertions, 0 deletions
diff --git a/src/lombok/core/SpiLoadUtil.java b/src/lombok/core/SpiLoadUtil.java
new file mode 100644
index 00000000..bf4bddf4
--- /dev/null
+++ b/src/lombok/core/SpiLoadUtil.java
@@ -0,0 +1,37 @@
+package lombok.core;
+
+import java.lang.annotation.Annotation;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+
+public class SpiLoadUtil {
+	private SpiLoadUtil() {}
+	
+	@SuppressWarnings("unchecked")
+	public static Class<? extends Annotation> findAnnotationClass(Class<?> c, Class<?> base) {
+		if ( c == Object.class || c == null ) return null;
+		for ( Type iface : c.getGenericInterfaces() ) {
+			if ( iface instanceof ParameterizedType ) {
+				ParameterizedType p = (ParameterizedType)iface;
+				if ( !base.equals(p.getRawType()) ) continue;
+				Type target = p.getActualTypeArguments()[0];
+				if ( target instanceof Class<?> ) {
+					if ( Annotation.class.isAssignableFrom((Class<?>) target) ) {
+						return (Class<? extends Annotation>) target;
+					}
+				}
+				
+				throw new ClassCastException("Not an annotation type: " + target);
+			}
+		}
+		
+		Class<? extends Annotation> potential = findAnnotationClass(c.getSuperclass(), base);
+		if ( potential != null ) return potential;
+		for ( Class<?> iface : c.getInterfaces() ) {
+			potential = findAnnotationClass(iface, base);
+			if ( potential != null ) return potential;
+		}
+		
+		return null;
+	}
+}