Some work wrt #588; minor refactoring to support custom ObjectWriter sub-classes

Author: cowtowncoder

src/main/java/com/fasterxml/jackson/databind/JsonSerializer.java

@@ -97,11 +97,11 @@ public JsonSerializer<T> replaceDelegatee(JsonSerializer<?> delegatee) {
      * values of type this serializer handles.
      *
      * @param value Value to serialize; can <b>not</b> be null.
-     * @param jgen Generator used to output resulting Json content
+     * @param gen Generator used to output resulting Json content
      * @param provider Provider that can be used to get serializers for
      *   serializing Objects value contains, if any.
      */
-    public abstract void serialize(T value, JsonGenerator jgen, SerializerProvider provider)
+    public abstract void serialize(T value, JsonGenerator gen, SerializerProvider provider)
         throws IOException, JsonProcessingException;
 
     /**
@@ -116,22 +116,22 @@ public abstract void serialize(T value, JsonGenerator jgen, SerializerProvider p
      * implementation would look like:
      *<pre>
      *  // note: method to call depends on whether this type is serialized as JSON scalar, object or Array!
-     *  typeSer.writeTypePrefixForScalar(value, jgen);
-     *  serialize(value, jgen, provider);
-     *  typeSer.writeTypeSuffixForScalar(value, jgen);
+     *  typeSer.writeTypePrefixForScalar(value, gen);
+     *  serialize(value, gen, provider);
+     *  typeSer.writeTypeSuffixForScalar(value, gen);
      *</pre>
      * and implementations for type serialized as JSON Arrays or Objects would differ slightly,
      * as <code>START-ARRAY>/<code>END-ARRAY</code> and
      * <code>START-OBJECT>/<code>END-OBJECT</code> pairs
      * need to be properly handled with respect to serializing of contents.
      *
      * @param value Value to serialize; can <b>not</b> be null.
-     * @param jgen Generator used to output resulting Json content
+     * @param gen Generator used to output resulting Json content
      * @param provider Provider that can be used to get serializers for
      *   serializing Objects value contains, if any.
      * @param typeSer Type serializer to use for including type information
      */
-    public void serializeWithType(T value, JsonGenerator jgen, SerializerProvider provider,
+    public void serializeWithType(T value, JsonGenerator gen, SerializerProvider provider,
             TypeSerializer typeSer)
         throws IOException, JsonProcessingException
     {
@@ -169,11 +169,30 @@ public void serializeWithType(T value, JsonGenerator jgen, SerializerProvider pr
      * Default implementation will consider only null values to be empty.
      * 
      * @since 2.0
+     * 
+     * @deprecated Since 2.5 Use {@link #isEmpty(SerializerProvider, Object)} instead
      */
+    @Deprecated
     public boolean isEmpty(T value) {
         return (value == null);
     }
 
+    /**
+     * Method called to check whether given serializable value is
+     * considered "empty" value (for purposes of suppressing serialization
+     * of empty values).
+     *<p>
+     * Default implementation will consider only null values to be empty.
+     *<p>
+     * NOTE: replaces {@link #isEmpty(Object)}, deprecated in 2.5
+     * 
+     * @since 2.5
+     */
+    public boolean isEmpty(SerializerProvider provider, T value) {
+        // replace with implementation in 2.6 or later
+        return isEmpty(value);
+    }
+    
     /**
      * Method that can be called to see whether this serializer instance
      * will use Object Id to handle cyclic references.

src/main/java/com/fasterxml/jackson/databind/ObjectReader.java

@@ -267,6 +267,7 @@ public Version version() {
     /**********************************************************
     /* Methods sub-classes MUST override, used for constructing
     /* reader instances, (re)configuring parser instances
+    /* Added in 2.5
     /**********************************************************
      */
 

src/main/java/com/fasterxml/jackson/databind/ObjectWriter.java

@@ -10,7 +10,6 @@
 import com.fasterxml.jackson.core.io.SegmentedStringWriter;
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.core.util.*;
-
 import com.fasterxml.jackson.databind.cfg.ContextAttributes;
 import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonFormatVisitorWrapper;
 import com.fasterxml.jackson.databind.ser.DefaultSerializerProvider;
@@ -233,7 +232,44 @@ protected ObjectWriter(ObjectWriter base, JsonFactory f)
     public Version version() {
         return com.fasterxml.jackson.databind.cfg.PackageVersion.VERSION;
     }
-    
+
+    /*
+    /**********************************************************
+    /* Methods sub-classes MUST override, used for constructing
+    /* reader instances, (re)configuring parser instances.
+    /* Added in 2.5
+    /**********************************************************
+     */
+
+    /**
+     * Overridable factory method called by various "withXxx()" methods
+     * 
+     * @since 2.5
+     */
+    protected ObjectWriter _new(ObjectWriter base, JsonFactory f) {
+        return new ObjectWriter(base, f);
+    }
+
+    /**
+     * Overridable factory method called by various "withXxx()" methods
+     * 
+     * @since 2.5
+     */
+    protected ObjectWriter _new(ObjectWriter base, SerializationConfig config) {
+        return new ObjectWriter(base, config);
+    }
+
+    /**
+     * Overridable factory method called by various "withXxx()" methods
+     * 
+     * @since 2.5
+     */
+    protected ObjectWriter _new(ObjectWriter base, SerializationConfig config,
+            JavaType rootType, JsonSerializer<Object> rootSer,
+            PrettyPrinter pp, FormatSchema s, CharacterEscapes escapes) {
+        return new ObjectWriter(base, config, rootType, rootSer, pp, s, escapes);
+    }
+
     /*
     /**********************************************************
     /* Life-cycle, fluent factories for SerializationFeature
@@ -246,7 +282,7 @@ public Version version() {
      */
     public ObjectWriter with(SerializationFeature feature)  {
         SerializationConfig newConfig = _config.with(feature);
-        return (newConfig == _config) ? this : new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this : _new(this, newConfig);
     }
 
     /**
@@ -255,7 +291,7 @@ public ObjectWriter with(SerializationFeature feature)  {
      */
     public ObjectWriter with(SerializationFeature first, SerializationFeature... other) {
         SerializationConfig newConfig = _config.with(first, other);
-        return (newConfig == _config) ? this : new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this : _new(this, newConfig);
     }    
 
     /**
@@ -264,7 +300,7 @@ public ObjectWriter with(SerializationFeature first, SerializationFeature... oth
      */
     public ObjectWriter withFeatures(SerializationFeature... features) {
         SerializationConfig newConfig = _config.withFeatures(features);
-        return (newConfig == _config) ? this : new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this : _new(this, newConfig);
     }    
 
     /**
@@ -273,7 +309,7 @@ public ObjectWriter withFeatures(SerializationFeature... features) {
      */
     public ObjectWriter without(SerializationFeature feature) {
         SerializationConfig newConfig = _config.without(feature);
-        return (newConfig == _config) ? this : new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this : _new(this, newConfig);
     }    
 
     /**
@@ -282,7 +318,7 @@ public ObjectWriter without(SerializationFeature feature) {
      */
     public ObjectWriter without(SerializationFeature first, SerializationFeature... other) {
         SerializationConfig newConfig = _config.without(first, other);
-        return (newConfig == _config) ? this : new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this : _new(this, newConfig);
     }    
 
     /**
@@ -291,7 +327,7 @@ public ObjectWriter without(SerializationFeature first, SerializationFeature...
      */
     public ObjectWriter withoutFeatures(SerializationFeature... features) {
         SerializationConfig newConfig = _config.withoutFeatures(features);
-        return (newConfig == _config) ? this : new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this : _new(this, newConfig);
     }
 
     /*
@@ -305,31 +341,31 @@ public ObjectWriter withoutFeatures(SerializationFeature... features) {
      */
     public ObjectWriter with(JsonGenerator.Feature feature)  {
         SerializationConfig newConfig = _config.with(feature);
-        return (newConfig == _config) ? this : new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this : _new(this, newConfig);
     }
 
     /**
      * @since 2.5
      */
     public ObjectWriter withFeatures(JsonGenerator.Feature... features) {
         SerializationConfig newConfig = _config.withFeatures(features);
-        return (newConfig == _config) ? this : new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this : _new(this, newConfig);
     }
 
     /**
      * @since 2.5
      */
     public ObjectWriter without(JsonGenerator.Feature feature) {
         SerializationConfig newConfig = _config.without(feature);
-        return (newConfig == _config) ? this : new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this : _new(this, newConfig);
     }
 
     /**
      * @since 2.5
      */
     public ObjectWriter withoutFeatures(JsonGenerator.Feature... features) {
         SerializationConfig newConfig = _config.withoutFeatures(features);
-        return (newConfig == _config) ? this : new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this : _new(this, newConfig);
     }
 
     /*
@@ -348,7 +384,7 @@ public ObjectWriter withoutFeatures(JsonGenerator.Feature... features) {
      */
     public ObjectWriter with(DateFormat df) {
         SerializationConfig newConfig = _config.with(df);
-        return (newConfig == _config) ? this : new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this : _new(this, newConfig);
     }
 
     /**
@@ -365,7 +401,7 @@ public ObjectWriter withDefaultPrettyPrinter() {
      */
     public ObjectWriter with(FilterProvider filterProvider) {
         return (filterProvider == _config.getFilterProvider()) ? this
-                 : new ObjectWriter(this, _config.withFilters(filterProvider));
+                 : _new(this, _config.withFilters(filterProvider));
     }
 
     /**
@@ -380,7 +416,7 @@ public ObjectWriter with(PrettyPrinter pp) {
         if (pp == null) {
             pp = NULL_PRETTY_PRINTER;
         }
-        return new ObjectWriter(this, _config, _rootType, _rootSerializer,
+        return _new(this, _config, _rootType, _rootSerializer,
                 pp, _schema, _characterEscapes);
     }
 
@@ -394,7 +430,7 @@ public ObjectWriter with(PrettyPrinter pp) {
      */
     public ObjectWriter withRootName(String rootName) {
         SerializationConfig newConfig = _config.withRootName(rootName);
-        return (newConfig == _config) ? this :  new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this :  _new(this, newConfig);
     }
 
     /**
@@ -409,7 +445,7 @@ public ObjectWriter with(FormatSchema schema) {
             return this;
         }
         _verifySchemaType(schema);
-        return new ObjectWriter(this, _config, _rootType, _rootSerializer,
+        return _new(this, _config, _rootType, _rootSerializer,
                 _prettyPrinter, schema, _characterEscapes);
     }
 
@@ -442,7 +478,7 @@ public ObjectWriter forType(JavaType rootType)
             rootType = rootType.withStaticTyping();
             rootSer = _prefetchRootSerializer(_config, rootType);
         }
-        return new ObjectWriter(this, _config, rootType, rootSer,
+        return _new(this, _config, rootType, rootSer,
                 _prettyPrinter, _schema, _characterEscapes);
     }    
 
@@ -498,17 +534,17 @@ public ObjectWriter withType(TypeReference<?> rootType) {
      */
     public ObjectWriter withView(Class<?> view) {
         SerializationConfig newConfig = _config.withView(view);
-        return (newConfig == _config) ? this :  new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this :  _new(this, newConfig);
     }    
 
     public ObjectWriter with(Locale l) {
         SerializationConfig newConfig = _config.with(l);
-        return (newConfig == _config) ? this :  new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this :  _new(this, newConfig);
     }
 
     public ObjectWriter with(TimeZone tz) {
         SerializationConfig newConfig = _config.with(tz);
-        return (newConfig == _config) ? this :  new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this :  _new(this, newConfig);
     }
 
     /**
@@ -519,7 +555,7 @@ public ObjectWriter with(TimeZone tz) {
      */
     public ObjectWriter with(Base64Variant b64variant) {
         SerializationConfig newConfig = _config.with(b64variant);
-        return (newConfig == _config) ? this :  new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this :  _new(this, newConfig);
     }
 
     /**
@@ -529,47 +565,47 @@ public ObjectWriter with(CharacterEscapes escapes) {
         if (_characterEscapes == escapes) {
             return this;
         }
-        return new ObjectWriter(this, _config, _rootType, _rootSerializer,
+        return _new(this, _config, _rootType, _rootSerializer,
                 _prettyPrinter, _schema, escapes);
     }
 
     /**
      * @since 2.3
      */
     public ObjectWriter with(JsonFactory f) {
-        return (f == _generatorFactory) ? this : new ObjectWriter(this, f);
+        return (f == _generatorFactory) ? this : _new(this, f);
     }    
 
     /**
      * @since 2.3
      */
     public ObjectWriter with(ContextAttributes attrs) {
         SerializationConfig newConfig = _config.with(attrs);
-        return (newConfig == _config) ? this :  new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this :  _new(this, newConfig);
     }
 
     /**
      * @since 2.3
      */
     public ObjectWriter withAttributes(Map<Object,Object> attrs) {
         SerializationConfig newConfig = _config.withAttributes(attrs);
-        return (newConfig == _config) ? this :  new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this :  _new(this, newConfig);
     }
 
     /**
      * @since 2.3
      */
     public ObjectWriter withAttribute(Object key, Object value) {
         SerializationConfig newConfig = _config.withAttribute(key, value);
-        return (newConfig == _config) ? this :  new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this :  _new(this, newConfig);
     }
 
     /**
      * @since 2.3
      */
     public ObjectWriter withoutAttribute(Object key) {
         SerializationConfig newConfig = _config.withoutAttribute(key);
-        return (newConfig == _config) ? this :  new ObjectWriter(this, newConfig);
+        return (newConfig == _config) ? this :  _new(this, newConfig);
     }
 
     /*

src/main/java/com/fasterxml/jackson/databind/deser/BeanDeserializer.java

@@ -241,14 +241,15 @@ private final Object vanillaDeserialize(JsonParser p,
         final Object bean = _valueInstantiator.createUsingDefault(ctxt);
         // [databind#631]: Assign current value, to be accessible by custom serializers
         p.setCurrentValue(bean);
+
         for (; t == JsonToken.FIELD_NAME; t = p.nextToken()) {
             String propName = p.getCurrentName();
             p.nextToken();
             if (!_beanProperties.findDeserializeAndSet(p, ctxt, bean, propName)) {
                 handleUnknownVanilla(p, ctxt, bean, propName);
             }
         }
-        
+
         // 13-Dec-2014, tatu: For 2.6, we'll do:
         /*
         if (p.hasTokenId(JsonTokenId.ID_FIELD_NAME)) {
@@ -261,7 +262,6 @@ private final Object vanillaDeserialize(JsonParser p,
             } while ((propName = p.nextFieldName()) != null);
         }
         */
-        
         return bean;
     }