From f033631b97cdf6978208ab274f65f19b5928b506 Mon Sep 17 00:00:00 2001
From: Arne Limburg <arne@apache.org>
Date: Mon, 29 Jun 2026 19:07:50 +0200
Subject: [PATCH] JOHNZON-431: Add detection of annotations at class level for
 constructor parameters

---
 .../apache/johnzon/jsonb/JsonbAccessMode.java |  6 ++-
 .../johnzon/jsonb/JsonbAdapterTest.java       | 48 +++++++++++++++++++
 2 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/johnzon-jsonb/src/main/java/org/apache/johnzon/jsonb/JsonbAccessMode.java b/johnzon-jsonb/src/main/java/org/apache/johnzon/jsonb/JsonbAccessMode.java
index 4ce308af3..a8de35639 100644
--- a/johnzon-jsonb/src/main/java/org/apache/johnzon/jsonb/JsonbAccessMode.java
+++ b/johnzon-jsonb/src/main/java/org/apache/johnzon/jsonb/JsonbAccessMode.java
@@ -1051,7 +1051,11 @@ private static <T extends Annotation> T getAnnotation(final Parameter param, fin
         if (annotation != null) {
             return annotation;
         }
-        return Meta.findMeta(param.getAnnotations(), api);
+        final T metaAnnotation = Meta.findMeta(param.getAnnotations(), api);
+        if (metaAnnotation != null) {
+            return metaAnnotation;
+        }
+        return Meta.getAnnotation(param.getType(), api);
     }
 
     @Override
diff --git a/johnzon-jsonb/src/test/java/org/apache/johnzon/jsonb/JsonbAdapterTest.java b/johnzon-jsonb/src/test/java/org/apache/johnzon/jsonb/JsonbAdapterTest.java
index e037ac4e1..34a4e230c 100644
--- a/johnzon-jsonb/src/test/java/org/apache/johnzon/jsonb/JsonbAdapterTest.java
+++ b/johnzon-jsonb/src/test/java/org/apache/johnzon/jsonb/JsonbAdapterTest.java
@@ -23,6 +23,9 @@
 import org.junit.Test;
 
 import jakarta.json.bind.adapter.JsonbAdapter;
+import jakarta.json.bind.annotation.JsonbCreator;
+import jakarta.json.bind.annotation.JsonbProperty;
+import jakarta.json.bind.annotation.JsonbTypeAdapter;
 
 import static org.junit.Assert.assertEquals;
 
@@ -43,6 +46,18 @@ public void testInheritedAdapterRecognized() {
         assertEquals("\"#336699\"", json);
     }
 
+    @Test
+    public void adapterAtConstructorParameterRecognized() {
+        // given
+        String json = "{\"innerValue\": \"value\"}";
+
+        // when
+        OuterObject object = jsonbRule.fromJson(json, OuterObject.class);
+
+        // then
+        assertEquals("value", object.innerObject.value);
+    }
+
     interface ValueType<T> {
         T value();
     }
@@ -76,4 +91,37 @@ public ColorId adaptFromJson(String s) throws Exception {
             return new ColorId(s);
         }
     }
+
+    public static class OuterObject {
+
+        private InnerObject innerObject;
+
+        @JsonbCreator
+        public OuterObject(@JsonbProperty("innerValue") InnerObject object) {
+            innerObject = object;
+        }
+    }
+
+    @JsonbTypeAdapter(InnerObjectAdapter.class)
+    static class InnerObject {
+
+        private String value;
+
+        public InnerObject(String value) {
+            this.value = value;
+        }
+    }
+
+    public static class InnerObjectAdapter implements JsonbAdapter<InnerObject, String> {
+
+        @Override
+        public String adaptToJson(InnerObject object) throws Exception {
+            return object.value;
+        }
+
+        @Override
+        public InnerObject adaptFromJson(String value) throws Exception {
+            return new InnerObject(value);
+        }
+    }
 }