Fix #3748: add missing overrides in DelegatingDeserializer (#3749)

FasterXML · Jan 22, 2023 · 186e831 · 186e831
1 parent 4113a82
commit 186e831
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diff --git a/release-notes/VERSION-2.x b/release-notes/VERSION-2.x
@@ -32,6 +32,8 @@ Project: jackson-databind
 #3736: Try to avoid auto-detecting Fields for Record types
 #3742: schemaType of `LongSerializer` is wrong
  (reported by @luozhenyu)
+#3748: `DelegatingDeserializer` missing override of `getAbsentValue()`
+ (and couple of other methods)
 
 2.14.2 (not yet released)
 

diff --git a/src/main/java/com/fasterxml/jackson/databind/deser/std/DelegatingDeserializer.java b/src/main/java/com/fasterxml/jackson/databind/deser/std/DelegatingDeserializer.java
@@ -10,11 +10,12 @@
 import com.fasterxml.jackson.databind.jsontype.TypeDeserializer;
 import com.fasterxml.jackson.databind.type.LogicalType;
 import com.fasterxml.jackson.databind.util.AccessPattern;
+import com.fasterxml.jackson.databind.util.NameTransformer;
 
 /**
  * Base class that simplifies implementations of {@link JsonDeserializer}s
  * that mostly delegate functionality to another deserializer implementation
- * (possibly forming a chaing of deserializers delegating functionality
+ * (possibly forming a chaining of deserializers delegating functionality
  * in some cases)
  * 
  * @since 2.1
@@ -26,7 +27,7 @@ public abstract class DelegatingDeserializer
     private static final long serialVersionUID = 1L;
 
     protected final JsonDeserializer<?> _delegatee;
-    
+
     /*
     /**********************************************************************
     /* Construction
@@ -46,7 +47,7 @@ public DelegatingDeserializer(JsonDeserializer<?> d)
      */
 
     protected abstract JsonDeserializer<?> newDelegatingInstance(JsonDeserializer<?> newDelegatee);
-    
+
     /*
     /**********************************************************************
     /* Overridden methods for contextualization, resolving
@@ -74,6 +75,16 @@ public JsonDeserializer<?> createContextual(DeserializationContext ctxt,
         return newDelegatingInstance(del);
     }
 
+    @SuppressWarnings("unchecked")
+    @Override
+    public JsonDeserializer<Object> unwrappingDeserializer(NameTransformer unwrapper) {
+        JsonDeserializer<?> unwrapping = _delegatee.unwrappingDeserializer(unwrapper);
+        if (unwrapping == _delegatee) {
+            return this;
+        }
+        return (JsonDeserializer<Object>) newDelegatingInstance(unwrapping);
+    }
+
     @Override
     public JsonDeserializer<?> replaceDelegatee(JsonDeserializer<?> delegatee)
     {
@@ -138,21 +149,31 @@ public SettableBeanProperty findBackReference(String logicalName) {
         return _delegatee.findBackReference(logicalName);
     }
 
+    @Override
+    public Object getNullValue(DeserializationContext ctxt) throws JsonMappingException {
+        return _delegatee.getNullValue(ctxt);
+    }
+
     @Override
     public AccessPattern getNullAccessPattern() {
         return _delegatee.getNullAccessPattern();
     }
 
     @Override
-    public Object getNullValue(DeserializationContext ctxt) throws JsonMappingException {
-        return _delegatee.getNullValue(ctxt);
+    public Object getAbsentValue(DeserializationContext ctxt) throws JsonMappingException {
+        return _delegatee.getAbsentValue(ctxt);
     }
 
     @Override
     public Object getEmptyValue(DeserializationContext ctxt) throws JsonMappingException {
         return _delegatee.getEmptyValue(ctxt);
     }
 
+    @Override
+    public AccessPattern getEmptyAccessPattern() {
+        return _delegatee.getEmptyAccessPattern();
+    }
+
     @Override // since 2.12
     public LogicalType logicalType() {
         return _delegatee.logicalType();

diff --git a/src/test/java/com/fasterxml/jackson/databind/ser/TestCustomSerializers.java b/src/test/java/com/fasterxml/jackson/databind/ser/TestCustomSerializers.java
@@ -15,12 +15,16 @@
 import com.fasterxml.jackson.core.io.CharacterEscapes;
 import com.fasterxml.jackson.databind.*;
 import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.fasterxml.jackson.databind.deser.std.DelegatingDeserializer;
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
 import com.fasterxml.jackson.databind.module.SimpleModule;
 import com.fasterxml.jackson.databind.ser.impl.SimpleBeanPropertyFilter;
 import com.fasterxml.jackson.databind.ser.impl.SimpleFilterProvider;
 import com.fasterxml.jackson.databind.ser.std.CollectionSerializer;
 import com.fasterxml.jackson.databind.ser.std.StdDelegatingSerializer;
 import com.fasterxml.jackson.databind.ser.std.StdScalarSerializer;
+import com.fasterxml.jackson.databind.util.AccessPattern;
+import com.fasterxml.jackson.databind.util.NameTransformer;
 import com.fasterxml.jackson.databind.util.StdConverter;
 
 /**
@@ -185,13 +189,61 @@ public String getId() {
         }
     }
 
+    // [databind#3748]
+    static class BaseDeserializer3748
+        extends StdDeserializer<String>
+    {
+        public BaseDeserializer3748() { super(String.class); }
+
+        @Override
+        public String deserialize(JsonParser p, DeserializationContext ctxt) {
+            return null;
+        }
+
+        @Override
+        public Object getEmptyValue(DeserializationContext ctxt) throws JsonMappingException {
+            return "empty";
+        }
+
+        @Override
+        public AccessPattern getEmptyAccessPattern() {
+            return AccessPattern.ALWAYS_NULL;
+        }
+
+        @Override
+        public Object getAbsentValue(DeserializationContext ctxt) {
+            return "absent";
+        }
+
+        @Override
+        public JsonDeserializer<String> unwrappingDeserializer(NameTransformer unwrapper) {
+            return new BaseDeserializer3748();
+        }
+    }
+
+    static class Delegating3748 extends DelegatingDeserializer
+    {
+        public Delegating3748() {
+            this(new BaseDeserializer3748());
+        }
+
+        public Delegating3748(JsonDeserializer<?> del) {
+            super(del);
+        }
+
+        @Override
+        protected JsonDeserializer<?> newDelegatingInstance(JsonDeserializer<?> newDelegatee) {
+            return new Delegating3748(newDelegatee);
+        }
+    }
+
     /*
     /**********************************************************
     /* Unit tests
     /**********************************************************
      */
 
-    private final ObjectMapper MAPPER = new ObjectMapper();
+    private final ObjectMapper MAPPER = newJsonMapper();
 
     public void testCustomization() throws Exception
     {
@@ -303,6 +355,17 @@ public void testIssue2475() throws Exception {
 
         assertEquals(a2q("{'id':'ID-2','set':[]}"),
                 writer.writeValueAsString(new Item2475(new HashSet<String>(), "ID-2")));
-    }    
+    }
 
+    // [databind#3748]
+    public void testBasicDelegatingDeser() throws Exception
+    {
+        Delegating3748 deser = new Delegating3748();
+        assertEquals("absent", deser.getAbsentValue(null));
+        assertEquals("empty", deser.getEmptyValue(null));
+        assertEquals(AccessPattern.ALWAYS_NULL, deser.getEmptyAccessPattern());
+        JsonDeserializer<?> unwrapping = deser.unwrappingDeserializer(null);
+        assertNotNull(unwrapping);
+        assertNotSame(deser, unwrapping);
+    }
 }