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

@@ -11,6 +11,7 @@
 import com.fasterxml.jackson.databind.deser.ResolvableDeserializer;
 import com.fasterxml.jackson.databind.jsontype.TypeDeserializer;
 import com.fasterxml.jackson.databind.type.LogicalType;
+import com.fasterxml.jackson.databind.type.SimpleType;
 import com.fasterxml.jackson.databind.type.TypeFactory;
 import com.fasterxml.jackson.databind.util.ClassUtil;
 import com.fasterxml.jackson.databind.util.ObjectBuffer;
@@ -48,6 +49,13 @@ 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 +82,7 @@ public class UntypedObjectDeserializer
  */
  @Deprecated
  public UntypedObjectDeserializer() {
- this(null, null);
+ this(null, (JavaType) null);
  }
 
  public UntypedObjectDeserializer(JavaType listType, JavaType mapType) {
@@ -96,6 +104,7 @@ public UntypedObjectDeserializer(UntypedObjectDeserializer base,
  _numberDeserializer = (JsonDeserializer<Object>) numberDeser;
  _listType = base._listType;
  _mapType = base._mapType;
+ _customKeyDeserializer = base._customKeyDeserializer;
  _nonMerging = base._nonMerging;
  }
 
@@ -112,9 +121,27 @@ 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
@@ -191,18 +218,32 @@ 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 keyDeser = ctxt.findKeyDeserializer(SimpleType.constructUnsafe(Object.class), property);
  // 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)
  && getClass() == UntypedObjectDeserializer.class) {
- return UntypedObjectDeserializerNR.instance(preventMerge);
+ if (keyDeser == null) {
+ return UntypedObjectDeserializerNR.instance(preventMerge);
+ }
  }
 
+ UntypedObjectDeserializer untyped = null;
  if (preventMerge != _nonMerging) {
- return new UntypedObjectDeserializer(this, preventMerge);
+ untyped = new UntypedObjectDeserializer(this, preventMerge);
+ }
+ if (keyDeser != null) {
+ if (untyped == null) {
+ untyped = new UntypedObjectDeserializer(this, keyDeser);
+ } else {
+ untyped = new UntypedObjectDeserializer(untyped, keyDeser);
+ }
+ }
+ if (untyped != null) {
+ return untyped;
  }
-
  return this;
  }
 
@@ -496,6 +537,8 @@ 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 {
+ 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 +551,8 @@ protected Object mapObject(JsonParser p, DeserializationContext ctxt) throws IOE
  LinkedHashMap<String, Object> result = new LinkedHashMap<>(2);
  result.put(key1, value1);
  return result;
+ } else {
+ key2 = (String) _customKeyDeserializer.deserializeKey(key2, ctxt);
  }
  p.nextToken();
  Object value2 = deserialize(p, ctxt);

src/test/java/com/fasterxml/jackson/databind/deser/CustomKeyDeserializer4680Test.java

@@ -0,0 +1,67 @@
+package com.fasterxml.jackson.databind.deser;
+
+import java.util.Map;
+
+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 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 CustomKeyDeserializer4680Test
+{
+
+ @Test
+ 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" +
+ " }";
+
+ SimpleModule keySanitizationModule = new SimpleModule("key-sanitization");
+ keySanitizationModule.addKeyDeserializer(String.class, new KeyDeserializer() {
+ @Override
+ public String deserializeKey(String key, DeserializationContext ctxt) {
+ return key.replace("*", "_");
+ }
+ });
+
+ keySanitizationModule.addKeyDeserializer(Object.class, new KeyDeserializer() {
+ @Override
+ public Object deserializeKey(String key, DeserializationContext ctxt) {
+ return key.replace("*", "_");
+ }
+ });
+
+ ObjectMapper mapper = JsonMapper.builder().addModule(keySanitizationModule).build();
+
+ // WHEN
+ Map<String, Object> result = mapper.readValue(json, new TypeReference<Map<String, Object>>() {
+ });
+
+ // THEN
+ // depth 1 works as expected
+ Assertions.assertEquals("Erik", result.get("name_"));
+
+ // before fix, depth 2 does NOT work as expected
+ Map<String, Object> addressMap = (Map<String, Object>) result.get("address_");
+ // before fix, null?? Fails here
+ Assertions.assertEquals("Elvirastr", addressMap.get("street_"));
+ Map<String, Object> cityMap = (Map<String, Object>) addressMap.get("city_");
+ Assertions.assertEquals(1, cityMap.get("id_"));
+ Assertions.assertEquals("Berlin", cityMap.get("name_"));
+ }
+
+}