fix #4680 : Custom key deserialiser registered for Object.class is ignored on nested JSON

src/main/java/com/fasterxml/jackson/databind/deser/std/UntypedObjectDeserializer.java

@@ -48,6 +48,13 @@ public class UntypedObjectDeserializer
 
     protected JsonDeserializer<Object> _numberDeserializer;
 
+    /**
+     * Object.class may also have custom key deserializer
+     *
+     * @since 2.19
+     */
+    private KeyDeserializer _customKeyDeserializer;
+
     /**
      * If {@link java.util.List} has been mapped to non-default implementation,
      * we'll store type here
@@ -74,7 +81,7 @@ public class UntypedObjectDeserializer
      */
     @Deprecated
     public UntypedObjectDeserializer() {
-        this(null, null);
+        this(null, (JavaType) null);
     }
 
     public UntypedObjectDeserializer(JavaType listType, JavaType mapType) {
@@ -96,6 +103,7 @@ public UntypedObjectDeserializer(UntypedObjectDeserializer base,
         _numberDeserializer = (JsonDeserializer<Object>) numberDeser;
         _listType = base._listType;
         _mapType = base._mapType;
+        _customKeyDeserializer = base._customKeyDeserializer;
         _nonMerging = base._nonMerging;
     }
 
@@ -112,9 +120,27 @@ protected UntypedObjectDeserializer(UntypedObjectDeserializer base,
         _numberDeserializer = base._numberDeserializer;
         _listType = base._listType;
         _mapType = base._mapType;
+        _customKeyDeserializer = base._customKeyDeserializer;
         _nonMerging = nonMerging;
     }
 
+    /**
+     * @since 2.19
+     */
+    protected UntypedObjectDeserializer(UntypedObjectDeserializer base,
+            KeyDeserializer keyDeser)
+    {
+        super(Object.class);
+        _mapDeserializer = base._mapDeserializer;
+        _listDeserializer = base._listDeserializer;
+        _stringDeserializer = base._stringDeserializer;
+        _numberDeserializer = base._numberDeserializer;
+        _listType = base._listType;
+        _mapType = base._mapType;
+        _nonMerging = base._nonMerging;
+        _customKeyDeserializer = keyDeser;
+    }
+
     /*
     /**********************************************************
     /* Initialization
@@ -191,19 +217,31 @@ public JsonDeserializer<?> createContextual(DeserializationContext ctxt,
         // 14-Jun-2017, tatu: [databind#1625]: may want to block merging, for root value
         boolean preventMerge = (property == null)
                 && Boolean.FALSE.equals(ctxt.getConfig().getDefaultMergeable(Object.class));
+        // 31-Aug-2024: [databind#4680] Allow custom key deserializer for Object.class deserialization
+        KeyDeserializer customKeyDeser = ctxt.findKeyDeserializer(ctxt.constructType(Object.class), property);
+        // but make sure to ignore standard/default key deserializer (perf optimization)
+        if (customKeyDeser != null) {
+            if (ClassUtil.isJacksonStdImpl(customKeyDeser)) {
+                customKeyDeser = null;
+            }
+        }
         // 20-Apr-2014, tatu: If nothing custom, let's use "vanilla" instance,
         //     simpler and can avoid some of delegation
         if ((_stringDeserializer == null) && (_numberDeserializer == null)
                 && (_mapDeserializer == null) && (_listDeserializer == null)
+                && (customKeyDeser == null)
                 &&  getClass() == UntypedObjectDeserializer.class) {
             return UntypedObjectDeserializerNR.instance(preventMerge);
         }
 
+        UntypedObjectDeserializer deser = this;
         if (preventMerge != _nonMerging) {
-            return new UntypedObjectDeserializer(this, preventMerge);
+            deser = new UntypedObjectDeserializer(deser, preventMerge);
         }
-
-        return this;
+        if (customKeyDeser != null) {
+            deser = new UntypedObjectDeserializer(deser, customKeyDeser);
+        }
+        return deser;
     }
 
     /*
@@ -496,6 +534,8 @@ protected Object mapObject(JsonParser p, DeserializationContext ctxt) throws IOE
         if (key1 == null) {
             // empty map might work; but caller may want to modify... so better just give small modifiable
             return new LinkedHashMap<>(2);
+        } else if (_customKeyDeserializer != null) {
+            key1 = (String) _customKeyDeserializer.deserializeKey(key1, ctxt);
         }
         // minor optimization; let's handle 1 and 2 entry cases separately
         // 24-Mar-2015, tatu: Ideally, could use one of 'nextXxx()' methods, but for
@@ -508,6 +548,8 @@ protected Object mapObject(JsonParser p, DeserializationContext ctxt) throws IOE
             LinkedHashMap<String, Object> result = new LinkedHashMap<>(2);
             result.put(key1, value1);
             return result;
+        } else if (_customKeyDeserializer != null) {
+            key2 = (String) _customKeyDeserializer.deserializeKey(key2, ctxt);
         }
         p.nextToken();
         Object value2 = deserialize(p, ctxt);

src/test/java/com/fasterxml/jackson/databind/tofix/CustomObjectKeyDeserializer4680Test.java → src/test/java/com/fasterxml/jackson/databind/deser/CustomKeyDeserializer4680Test.java

@@ -1,39 +1,34 @@
-package com.fasterxml.jackson.databind.tofix;
+package com.fasterxml.jackson.databind.deser;
 
 import java.util.Map;
 
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.DeserializationContext;
 import com.fasterxml.jackson.databind.KeyDeserializer;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.json.JsonMapper;
 import com.fasterxml.jackson.databind.module.SimpleModule;
-import com.fasterxml.jackson.databind.testutil.failure.JacksonTestFailureExpected;
-
-import org.junit.jupiter.api.Assertions;
-import org.junit.jupiter.api.Test;
 
 // [databind#4680] Custom key deserialiser registered for `Object.class` is ignored on nested JSON
-public class CustomObjectKeyDeserializer4680Test
+public class CustomKeyDeserializer4680Test
 {
-
-    @JacksonTestFailureExpected
+    // [databind#4680]
     @Test
-    void testCustomKeyDeserializer()
-            throws Exception
-    {
+    void customKeyDeserializerShouldBeUsedWhenTypeNotDefined() throws Exception {
         // GIVEN
-        String json =
-                "{\n" +
-                        "     \"name*\": \"Erik\",\n" +
-                        "     \"address*\": {\n" +
-                        "         \"city*\": {\n" +
-                        "             \"id*\": 1,\n" +
-                        "             \"name*\": \"Berlin\"\n" +
-                        "         },\n" +
-                        "         \"street*\": \"Elvirastr\"\n" +
-                        "     }\n" +
-                        " }";
+        String json = "{\n" +
+                "                    \"name*\": \"Erik\",\n" +
+                "                    \"address*\": {\n" +
+                "                        \"city*\": {\n" +
+                "                            \"id*\": 1,\n" +
+                "                            \"name*\": \"Berlin\"\n" +
+                "                        },\n" +
+                "                        \"street*\": \"Elvirastr\"\n" +
+                "                    }\n" +
+                "                }";
 
         SimpleModule keySanitizationModule = new SimpleModule("key-sanitization");
         keySanitizationModule.addKeyDeserializer(String.class, new KeyDeserializer() {
@@ -69,4 +64,4 @@ public Object deserializeKey(String key, DeserializationContext ctxt) {
         Assertions.assertEquals("Berlin", cityMap.get("name_"));
     }
 
-}
+}