Implemented #165: Add DeserializationContext.getContextualType() wh…

…ich can be called by contextual deserializers to know nominal type for them, without needing to decipher it from `BeanProperty`
FasterXML · Dec 27, 2014 · c4b6c61 · c4b6c61
1 parent 53d4c4c
commit c4b6c61
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Showing 16 changed files with 145 additions and 47 deletions.
diff --git a/release-notes/VERSION b/release-notes/VERSION
@@ -8,6 +8,8 @@ Project: jackson-databind
 
 #47: Support `@JsonValue` for (Map) key serialization 
 #113: Problem deserializing polymorphic types with @JsonCreator
+#165: Add `DeserializationContext.getContextualType()` to let deserializer
+  known the expected type.
 #408: External type id does not allow use of 'visible=true'
 #421: @JsonCreator not used in case of multiple creators with parameter names
  (reported by Lovro P, lpandzic@github)

diff --git a/src/main/java/com/fasterxml/jackson/databind/DeserializationContext.java b/src/main/java/com/fasterxml/jackson/databind/DeserializationContext.java
@@ -128,6 +128,15 @@ public abstract class DeserializationContext
      * @since 2.3
      */
     protected transient ContextAttributes _attributes;
+
+    /**
+     * Type of {@link JsonDeserializer} (or, more specifically,
+     *   {@link ContextualizableDeserializer}) that is being
+     *   contextualized currently.
+     *
+     * @since 2.5
+     */
+    protected LinkedNode<JavaType> _currentType;
 
     /*
     /**********************************************************
@@ -224,7 +233,7 @@ public final TypeFactory getTypeFactory() {
 
     /*
     /**********************************************************
-    /* Generic attributes (2.3+)
+    /* Access to per-call state, like generic attributes (2.3+)
     /**********************************************************
      */
 
@@ -239,10 +248,27 @@ public DeserializationContext setAttribute(Object key, Object value)
         _attributes = _attributes.withPerCallAttribute(key, value);
         return this;
     }
-
+
+    /**
+     * Accessor to {@link JavaType} of currently contextualized
+     * {@link ContextualDeserializer}, if any.
+     * This is sometimes useful for generic {@link JsonDeserializer}s that
+     * do not get passed (or do not retain) type information when being
+     * constructed: happens for example for deserializers constructed
+     * from annotations.
+     * 
+     * @since 2.5
+     *
+     * @return Type of {@link ContextualDeserializer} being contextualized,
+     *   if process is on-going; null if not.
+     */
+    public JavaType getContextualType() {
+        return (_currentType == null) ? null : _currentType.value();
+    }
+
     /*
     /**********************************************************
-    /* Public API, accessors
+    /* Public API, config setting accessors
     /**********************************************************
      */
 
@@ -379,7 +405,7 @@ public final JsonDeserializer<Object> findContextualValueDeserializer(JavaType t
     {
         JsonDeserializer<Object> deser = _cache.findValueDeserializer(this, _factory, type);
         if (deser != null) {
-            deser = (JsonDeserializer<Object>) handleSecondaryContextualization(deser, prop);
+            deser = (JsonDeserializer<Object>) handleSecondaryContextualization(deser, prop, type);
         }
         return deser;
     }
@@ -391,8 +417,8 @@ public final JsonDeserializer<Object> findContextualValueDeserializer(JavaType t
      * {@link #findRootValueDeserializer(JavaType)}.
      * This method is usually called from within {@link ResolvableDeserializer#resolve},
      * and expectation is that caller then calls either
-     * {@link #handlePrimaryContextualization(JsonDeserializer, BeanProperty)} or
-     * {@link #handleSecondaryContextualization(JsonDeserializer, BeanProperty)} at a
+     * {@link #handlePrimaryContextualization(JsonDeserializer, BeanProperty, JavaType)} or
+     * {@link #handleSecondaryContextualization(JsonDeserializer, BeanProperty, JavaType)} at a
      * later point, as necessary.
      *
      * @since 2.5
@@ -415,7 +441,7 @@ public final JsonDeserializer<Object> findRootValueDeserializer(JavaType type)
         if (deser == null) { // can this occur?
             return null;
         }
-        deser = (JsonDeserializer<Object>) handleSecondaryContextualization(deser, null);
+        deser = (JsonDeserializer<Object>) handleSecondaryContextualization(deser, null, type);
         TypeDeserializer typeDeser = _factory.findTypeDeserializer(_config, type);
         if (typeDeser != null) {
             // important: contextualize to indicate this is for root value
@@ -576,18 +602,31 @@ public abstract KeyDeserializer keyDeserializerInstance(Annotated annotated,
      * 
      * @param prop Property for which the given primary deserializer is used; never null.
      * 
-     * @since 2.3
+     * @since 2.5
      */
     public JsonDeserializer<?> handlePrimaryContextualization(JsonDeserializer<?> deser,
-            BeanProperty prop)
+            BeanProperty prop, JavaType type)
         throws JsonMappingException
     {
         if (deser instanceof ContextualDeserializer) {
-            deser = ((ContextualDeserializer) deser).createContextual(this, prop);
+            _currentType = new LinkedNode<JavaType>(type, _currentType);
+            try {
+                deser = ((ContextualDeserializer) deser).createContextual(this, prop);
+            } finally {
+                _currentType = _currentType.next();
+            }
         }
         return deser;
     }
 
+    @Deprecated // since 2.5; remove from 2.6
+    public JsonDeserializer<?> handlePrimaryContextualization(JsonDeserializer<?> deser,
+            BeanProperty prop)
+        throws JsonMappingException
+    {
+        return handlePrimaryContextualization(deser, prop, TypeFactory.unknownType());
+    }
+
     /**
      * Method called for secondary property deserializers (ones
      * NOT directly created to deal with an annotatable POJO property,
@@ -602,8 +641,24 @@ public JsonDeserializer<?> handlePrimaryContextualization(JsonDeserializer<?> de
      * @param prop Property for which deserializer is used, if any; null
      *    when deserializing root values
      * 
-     * @since 2.3
+     * @since 2.5
      */
+    public JsonDeserializer<?> handleSecondaryContextualization(JsonDeserializer<?> deser,
+            BeanProperty prop, JavaType type)
+        throws JsonMappingException
+    {
+        if (deser instanceof ContextualDeserializer) {
+            _currentType = new LinkedNode<JavaType>(type, _currentType);
+            try {
+                deser = ((ContextualDeserializer) deser).createContextual(this, prop);
+            } finally {
+                _currentType = _currentType.next();
+            }
+        }
+        return deser;
+    }
+
+    @Deprecated // since 2.5; remove from 2.6
     public JsonDeserializer<?> handleSecondaryContextualization(JsonDeserializer<?> deser,
             BeanProperty prop)
         throws JsonMappingException
@@ -613,7 +668,7 @@ public JsonDeserializer<?> handleSecondaryContextualization(JsonDeserializer<?>
         }
         return deser;
     }
-    
+
     /*
     /**********************************************************
     /* Parsing methods that may use reusable/-cyclable objects

diff --git a/src/main/java/com/fasterxml/jackson/databind/deser/BasicDeserializerFactory.java b/src/main/java/com/fasterxml/jackson/databind/deser/BasicDeserializerFactory.java
@@ -797,7 +797,7 @@ protected CreatorProperty constructCreatorProperty(DeserializationContext ctxt,
                 metadata);
         if (deser != null) {
             // As per [Issue#462] need to ensure we contextualize deserializer before passing it on
-            deser = ctxt.handlePrimaryContextualization(deser, prop);
+            deser = ctxt.handlePrimaryContextualization(deser, prop, type);
             prop = prop.withValueDeserializer(deser);
         }
         return prop;

diff --git a/src/main/java/com/fasterxml/jackson/databind/deser/BeanDeserializerBase.java b/src/main/java/com/fasterxml/jackson/databind/deser/BeanDeserializerBase.java
@@ -441,7 +441,8 @@ public void resolve(DeserializationContext ctxt)
                 /* Important! This is the only place where actually handle "primary"
                  * property deserializers -- call is different from other places.
                  */
-                JsonDeserializer<?> cd = ctxt.handlePrimaryContextualization(deser, prop);
+                JsonDeserializer<?> cd = ctxt.handlePrimaryContextualization(deser, prop,
+                        prop.getType());
                 if (cd != deser) {
                     prop = prop.withValueDeserializer(cd);
                 }

diff --git a/src/main/java/com/fasterxml/jackson/databind/deser/std/CollectionDeserializer.java b/src/main/java/com/fasterxml/jackson/databind/deser/std/CollectionDeserializer.java
@@ -154,11 +154,11 @@ public CollectionDeserializer createContextual(DeserializationContext ctxt,
         JsonDeserializer<?> valueDeser = _valueDeserializer;
         // #125: May have a content converter
         valueDeser = findConvertingContentDeserializer(ctxt, property, valueDeser);
+        final JavaType vt = _collectionType.getContentType();
         if (valueDeser == null) {
-            valueDeser = ctxt.findContextualValueDeserializer(
-                    _collectionType.getContentType(), property);
+            valueDeser = ctxt.findContextualValueDeserializer(vt, property);
         } else { // if directly assigned, probably not yet contextual, so:
-            valueDeser = ctxt.handleSecondaryContextualization(valueDeser, property);
+            valueDeser = ctxt.handleSecondaryContextualization(valueDeser, property, vt);
         }
         // and finally, type deserializer needs context as well
         TypeDeserializer valueTypeDeser = _valueTypeDeserializer;

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
@@ -67,7 +67,9 @@ public JsonDeserializer<?> createContextual(DeserializationContext ctxt,
             BeanProperty property)
         throws JsonMappingException
     {
-        JsonDeserializer<?> del = ctxt.handleSecondaryContextualization(_delegatee, property);
+        JavaType vt = ctxt.constructType(_delegatee.handledType());
+        JsonDeserializer<?> del = ctxt.handleSecondaryContextualization(_delegatee,
+                property, vt);
         if (del == _delegatee) {
             return this;
         }

diff --git a/src/main/java/com/fasterxml/jackson/databind/deser/std/EnumMapDeserializer.java b/src/main/java/com/fasterxml/jackson/databind/deser/std/EnumMapDeserializer.java
@@ -74,10 +74,11 @@ public JsonDeserializer<?> createContextual(DeserializationContext ctxt, BeanPro
             kd = ctxt.findKeyDeserializer(_mapType.getKeyType(), property);
         }
         JsonDeserializer<?> vd = _valueDeserializer;
+        final JavaType vt = _mapType.getContentType();
         if (vd == null) {
-            vd = ctxt.findContextualValueDeserializer(_mapType.getContentType(), property);
+            vd = ctxt.findContextualValueDeserializer(vt, property);
         } else { // if directly assigned, probably not yet contextual, so:
-            vd = ctxt.handleSecondaryContextualization(vd, property);
+            vd = ctxt.handleSecondaryContextualization(vd, property, vt);
         }
         TypeDeserializer vtd = _valueTypeDeserializer;
         if (vtd != null) {

diff --git a/src/main/java/com/fasterxml/jackson/databind/deser/std/EnumSetDeserializer.java b/src/main/java/com/fasterxml/jackson/databind/deser/std/EnumSetDeserializer.java
@@ -64,7 +64,7 @@ public JsonDeserializer<?> createContextual(DeserializationContext ctxt,
         if (deser == null) {
             deser = ctxt.findContextualValueDeserializer(_enumType, property);
         } else { // if directly assigned, probably not yet contextual, so:
-            deser = ctxt.handleSecondaryContextualization(deser, property);
+            deser = ctxt.handleSecondaryContextualization(deser, property, _enumType);
         }
         return withDeserializer(deser);
     }

diff --git a/src/main/java/com/fasterxml/jackson/databind/deser/std/MapDeserializer.java b/src/main/java/com/fasterxml/jackson/databind/deser/std/MapDeserializer.java
@@ -236,10 +236,11 @@ public JsonDeserializer<?> createContextual(DeserializationContext ctxt,
         JsonDeserializer<?> vd = _valueDeserializer;
         // #125: May have a content converter
         vd = findConvertingContentDeserializer(ctxt, property, vd);
+        final JavaType vt = _mapType.getContentType();
         if (vd == null) {
-            vd = ctxt.findContextualValueDeserializer(_mapType.getContentType(), property);
+            vd = ctxt.findContextualValueDeserializer(vt, property);
         } else { // if directly assigned, probably not yet contextual, so:
-            vd = ctxt.handleSecondaryContextualization(vd, property);
+            vd = ctxt.handleSecondaryContextualization(vd, property, vt);
         }
         TypeDeserializer vtd = _valueTypeDeserializer;
         if (vtd != null) {

diff --git a/src/main/java/com/fasterxml/jackson/databind/deser/std/MapEntryDeserializer.java b/src/main/java/com/fasterxml/jackson/databind/deser/std/MapEntryDeserializer.java
@@ -132,10 +132,11 @@ public JsonDeserializer<?> createContextual(DeserializationContext ctxt,
         }
         JsonDeserializer<?> vd = _valueDeserializer;
         vd = findConvertingContentDeserializer(ctxt, property, vd);
+        JavaType contentType = _type.containedType(1);
         if (vd == null) {
-            vd = ctxt.findContextualValueDeserializer(_type.containedType(1), property);
+            vd = ctxt.findContextualValueDeserializer(contentType, property);
         } else { // if directly assigned, probably not yet contextual, so:
-            vd = ctxt.handleSecondaryContextualization(vd, property);
+            vd = ctxt.handleSecondaryContextualization(vd, property, contentType);
         }
         TypeDeserializer vtd = _valueTypeDeserializer;
         if (vtd != null) {

diff --git a/src/main/java/com/fasterxml/jackson/databind/deser/std/ObjectArrayDeserializer.java b/src/main/java/com/fasterxml/jackson/databind/deser/std/ObjectArrayDeserializer.java
@@ -89,10 +89,11 @@ public JsonDeserializer<?> createContextual(DeserializationContext ctxt,
         JsonDeserializer<?> deser = _elementDeserializer;
         // #125: May have a content converter
         deser = findConvertingContentDeserializer(ctxt, property, deser);
+        final JavaType vt = _arrayType.getContentType();
         if (deser == null) {
-            deser = ctxt.findContextualValueDeserializer(_arrayType.getContentType(), property);
+            deser = ctxt.findContextualValueDeserializer(vt, property);
         } else { // if directly assigned, probably not yet contextual, so:
-            deser = ctxt.handleSecondaryContextualization(deser, property);
+            deser = ctxt.handleSecondaryContextualization(deser, property, vt);
         }
         TypeDeserializer elemTypeDeser = _elementTypeDeserializer;
         if (elemTypeDeser != null) {

diff --git a/src/main/java/com/fasterxml/jackson/databind/deser/std/StdDelegatingDeserializer.java b/src/main/java/com/fasterxml/jackson/databind/deser/std/StdDelegatingDeserializer.java
@@ -119,7 +119,8 @@ public JsonDeserializer<?> createContextual(DeserializationContext ctxt, BeanPro
     {
         // First: if already got serializer to delegate to, contextualize it:
         if (_delegateDeserializer != null) {
-            JsonDeserializer<?> deser = ctxt.handleSecondaryContextualization(_delegateDeserializer, property);
+            JsonDeserializer<?> deser = ctxt.handleSecondaryContextualization(_delegateDeserializer,
+                    property, _delegateType);
             if (deser != _delegateDeserializer) {
                 return withDelegate(_converter, _delegateType, deser);
             }

diff --git a/src/main/java/com/fasterxml/jackson/databind/deser/std/StringArrayDeserializer.java b/src/main/java/com/fasterxml/jackson/databind/deser/std/StringArrayDeserializer.java
@@ -144,10 +144,11 @@ public JsonDeserializer<?> createContextual(DeserializationContext ctxt, BeanPro
         JsonDeserializer<?> deser = _elementDeserializer;
         // #125: May have a content converter
         deser = findConvertingContentDeserializer(ctxt, property, deser);
+        JavaType type = ctxt.constructType(String.class);
         if (deser == null) {
-            deser = ctxt.findContextualValueDeserializer(ctxt.constructType(String.class), property);
+            deser = ctxt.findContextualValueDeserializer(type, property);
         } else { // if directly assigned, probably not yet contextual, so:
-            deser = ctxt.handleSecondaryContextualization(deser, property);
+            deser = ctxt.handleSecondaryContextualization(deser, property, type);
         }
         // Ok ok: if all we got is the default String deserializer, can just forget about it
         if (deser != null && this.isDefaultDeserializer(deser)) {

diff --git a/src/main/java/com/fasterxml/jackson/databind/deser/std/StringCollectionDeserializer.java b/src/main/java/com/fasterxml/jackson/databind/deser/std/StringCollectionDeserializer.java
@@ -106,15 +106,16 @@ public JsonDeserializer<?> createContextual(DeserializationContext ctxt,
             }
         }
         JsonDeserializer<?> valueDeser = _valueDeserializer;
+        final JavaType valueType = _collectionType.getContentType();
         if (valueDeser == null) {
             // #125: May have a content converter
             valueDeser = findConvertingContentDeserializer(ctxt, property, valueDeser);
             if (valueDeser == null) {
             // And we may also need to get deserializer for String
-                valueDeser = ctxt.findContextualValueDeserializer( _collectionType.getContentType(), property);
+                valueDeser = ctxt.findContextualValueDeserializer(valueType, property);
             }
         } else { // if directly assigned, probably not yet contextual, so:
-            valueDeser = ctxt.handleSecondaryContextualization(valueDeser, property);
+            valueDeser = ctxt.handleSecondaryContextualization(valueDeser, property, valueType);
         } 
         if (isDefaultDeserializer(valueDeser)) {
             valueDeser = null;

diff --git a/src/main/java/com/fasterxml/jackson/databind/deser/std/UntypedObjectDeserializer.java b/src/main/java/com/fasterxml/jackson/databind/deser/std/UntypedObjectDeserializer.java
@@ -109,10 +109,11 @@ public void resolve(DeserializationContext ctxt) throws JsonMappingException
 
         // and then do bogus contextualization, in case custom ones need to resolve dependencies of
         // their own
-        _mapDeserializer = (JsonDeserializer<Object>) ctxt.handleSecondaryContextualization(_mapDeserializer, null);
-        _listDeserializer = (JsonDeserializer<Object>) ctxt.handleSecondaryContextualization(_listDeserializer, null);
-        _stringDeserializer = (JsonDeserializer<Object>) ctxt.handleSecondaryContextualization(_stringDeserializer, null);
-        _numberDeserializer = (JsonDeserializer<Object>) ctxt.handleSecondaryContextualization(_numberDeserializer, null);
+        JavaType unknown = TypeFactory.unknownType();
+        _mapDeserializer = (JsonDeserializer<Object>) ctxt.handleSecondaryContextualization(_mapDeserializer, null, unknown);
+        _listDeserializer = (JsonDeserializer<Object>) ctxt.handleSecondaryContextualization(_listDeserializer, null, unknown);
+        _stringDeserializer = (JsonDeserializer<Object>) ctxt.handleSecondaryContextualization(_stringDeserializer, null, unknown);
+        _numberDeserializer = (JsonDeserializer<Object>) ctxt.handleSecondaryContextualization(_numberDeserializer, null, unknown);
     }
 
     @SuppressWarnings("unchecked")