Search recursively through all annotations to find @Extension#347

1 files changed, 20 insertions, 4 deletions

diff --git a/pf4j/src/main/java/org/pf4j/AbstractExtensionFinder.java b/pf4j/src/main/java/org/pf4j/AbstractExtensionFinder.java
index b260c39..3cfbc7e 100644
--- a/pf4j/src/main/java/org/pf4j/AbstractExtensionFinder.java
+++ b/pf4j/src/main/java/org/pf4j/AbstractExtensionFinder.java
@@ -20,6 +20,7 @@ import org.pf4j.util.ClassUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.lang.annotation.Annotation;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
@@ -340,15 +341,30 @@ public abstract class AbstractExtensionFinder implements ExtensionFinder, Plugin
     }
 
     private ExtensionWrapper createExtensionWrapper(Class<?> extensionClass) {
-        int ordinal = 0;
-        if (extensionClass.isAnnotationPresent(Extension.class)) {
-            ordinal = extensionClass.getAnnotation(Extension.class).ordinal();
-        }
+        Extension extensionAnnotation = findExtensionAnnotation(extensionClass);
+        int ordinal = extensionAnnotation != null ? extensionAnnotation.ordinal() : 0;
         ExtensionDescriptor descriptor = new ExtensionDescriptor(ordinal, extensionClass);
 
         return new ExtensionWrapper<>(descriptor, pluginManager.getExtensionFactory());
     }
 
+    private Extension findExtensionAnnotation(Class<?> clazz) {
+        if (clazz.isAnnotationPresent(Extension.class)) {
+            return clazz.getAnnotation(Extension.class);
+        }
+
+        // search recursively through all annotations
+        for (Annotation annotation : clazz.getAnnotations()) {
+            Class<? extends Annotation> annotationClass = annotation.annotationType();
+            Extension extensionAnnotation = findExtensionAnnotation(annotationClass);
+            if (extensionAnnotation != null) {
+                return extensionAnnotation;
+            }
+        }
+
+        return null;
+    }
+
     private void checkDifferentClassLoaders(Class<?> type, Class<?> extensionClass) {
         ClassLoader typeClassLoader = type.getClassLoader(); // class loader of extension point
         ClassLoader extensionClassLoader = extensionClass.getClassLoader();