ReferenceTypeSerializer.java
package com.fasterxml.jackson.databind.ser.std;
import java.io.IOException;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.fasterxml.jackson.databind.introspect.Annotated;
import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonFormatVisitorWrapper;
import com.fasterxml.jackson.databind.jsontype.TypeSerializer;
import com.fasterxml.jackson.databind.ser.ContextualSerializer;
import com.fasterxml.jackson.databind.ser.impl.PropertySerializerMap;
import com.fasterxml.jackson.databind.type.ReferenceType;
import com.fasterxml.jackson.databind.util.ArrayBuilders;
import com.fasterxml.jackson.databind.util.BeanUtil;
import com.fasterxml.jackson.databind.util.NameTransformer;
/**
* Base implementation for values of {@link ReferenceType}.
* Implements most of functionality, only leaving couple of abstract
* methods for sub-classes to implement.
*
* @since 2.8
*/
public abstract class ReferenceTypeSerializer<T>
extends StdSerializer<T>
implements ContextualSerializer
{
private static final long serialVersionUID = 1L;
/**
* @since 2.9
*/
public final static Object MARKER_FOR_EMPTY = JsonInclude.Include.NON_EMPTY;
/**
* Value type
*/
protected final JavaType _referredType;
protected final BeanProperty _property;
/**
* Type serializer used for values, if any.
*/
protected final TypeSerializer _valueTypeSerializer;
/**
* Serializer for content values, if statically known.
*/
protected final JsonSerializer<Object> _valueSerializer;
/**
* In case of unwrapping, need name transformer.
*/
protected final NameTransformer _unwrapper;
/**
* If element type cannot be statically determined, mapping from
* runtime type to serializer is handled using this object
*/
protected transient PropertySerializerMap _dynamicSerializers;
/*
/**********************************************************
/* Config settings, filtering
/**********************************************************
*/
/**
* Value that indicates suppression mechanism to use for <b>values contained</b>;
* either "filter" (of which <code>equals()</code> is called), or marker
* value of {@link #MARKER_FOR_EMPTY}, or null to indicate no filtering for
* non-null values.
* Note that inclusion value for Map instance itself is handled by caller (POJO
* property that refers to the Map value).
*
* @since 2.9
*/
protected final Object _suppressableValue;
/**
* Flag that indicates what to do with `null` values, distinct from
* handling of {@link #_suppressableValue}
*
* @since 2.9
*/
protected final boolean _suppressNulls;
/*
/**********************************************************
/* Constructors, factory methods
/**********************************************************
*/
public ReferenceTypeSerializer(ReferenceType fullType, boolean staticTyping,
TypeSerializer vts, JsonSerializer<Object> ser)
{
super(fullType);
_referredType = fullType.getReferencedType();
_property = null;
_valueTypeSerializer = vts;
_valueSerializer = ser;
_unwrapper = null;
_suppressableValue = null;
_suppressNulls = false;
_dynamicSerializers = PropertySerializerMap.emptyForProperties();
}
@SuppressWarnings("unchecked")
protected ReferenceTypeSerializer(ReferenceTypeSerializer<?> base, BeanProperty property,
TypeSerializer vts, JsonSerializer<?> valueSer,
NameTransformer unwrapper,
Object suppressableValue, boolean suppressNulls)
{
super(base);
_referredType = base._referredType;
// [databind#2181]: may not be safe to reuse, start from empty
_dynamicSerializers = PropertySerializerMap.emptyForProperties();
_property = property;
_valueTypeSerializer = vts;
_valueSerializer = (JsonSerializer<Object>) valueSer;
_unwrapper = unwrapper;
_suppressableValue = suppressableValue;
_suppressNulls = suppressNulls;
}
@Override
public JsonSerializer<T> unwrappingSerializer(NameTransformer transformer) {
JsonSerializer<Object> valueSer = _valueSerializer;
if (valueSer != null) {
// 09-Dec-2019, tatu: [databind#2565] Can not assume that serializer in
// question actually can unwrap
valueSer = valueSer.unwrappingSerializer(transformer);
if (valueSer == _valueSerializer) {
return this;
}
}
NameTransformer unwrapper = (_unwrapper == null) ? transformer
: NameTransformer.chainedTransformer(transformer, _unwrapper);
if ((_valueSerializer == valueSer) && (_unwrapper == unwrapper)) {
return this;
}
return withResolved(_property, _valueTypeSerializer, valueSer, unwrapper);
}
/*
/**********************************************************
/* Abstract methods to implement
/**********************************************************
*/
/**
* Mutant factory method called when changes are needed; should construct
* newly configured instance with new values as indicated.
*<p>
* NOTE: caller has verified that there are changes, so implementations
* need NOT check if a new instance is needed.
*
* @since 2.9
*/
protected abstract ReferenceTypeSerializer<T> withResolved(BeanProperty prop,
TypeSerializer vts, JsonSerializer<?> valueSer,
NameTransformer unwrapper);
/**
* Mutant factory method called to create a differently constructed instance,
* specifically with different exclusion rules for contained value.
*<p>
* NOTE: caller has verified that there are changes, so implementations
* need NOT check if a new instance is needed.
*
* @since 2.9
*/
public abstract ReferenceTypeSerializer<T> withContentInclusion(Object suppressableValue,
boolean suppressNulls);
/**
* Method called to see if there is a value present or not.
* Note that value itself may still be `null`, even if present,
* if referential type allows three states (absent, present-null,
* present-non-null); some only allow two (absent, present-non-null).
*/
protected abstract boolean _isValuePresent(T value);
protected abstract Object _getReferenced(T value);
protected abstract Object _getReferencedIfPresent(T value);
/*
/**********************************************************
/* Contextualization (support for property annotations)
/**********************************************************
*/
@Override
public JsonSerializer<?> createContextual(SerializerProvider provider,
BeanProperty property) throws JsonMappingException
{
TypeSerializer typeSer = _valueTypeSerializer;
if (typeSer != null) {
typeSer = typeSer.forProperty(property);
}
// First: do we have an annotation override from property?
JsonSerializer<?> ser = findAnnotatedContentSerializer(provider, property);
if (ser == null) {
// If not, use whatever was configured by type
ser = _valueSerializer;
if (ser == null) {
// A few conditions needed to be able to fetch serializer here:
if (_useStatic(provider, property, _referredType)) {
ser = _findSerializer(provider, _referredType, property);
}
} else {
ser = provider.handlePrimaryContextualization(ser, property);
}
}
// 23-Jan-2024, tatu: [databind#4337]: May have a content converter
ser = findContextualConvertingSerializer(provider, property, ser);
// First, resolve wrt property, resolved serializers
ReferenceTypeSerializer<?> refSer;
if ((_property == property)
&& (_valueTypeSerializer == typeSer) && (_valueSerializer == ser)) {
refSer = this;
} else {
refSer = withResolved(property, typeSer, ser, _unwrapper);
}
// and then see if we have property-inclusion overrides
if (property != null) {
JsonInclude.Value inclV = property.findPropertyInclusion(provider.getConfig(), handledType());
if (inclV != null) {
JsonInclude.Include incl = inclV.getContentInclusion();
if (incl != JsonInclude.Include.USE_DEFAULTS) {
Object valueToSuppress;
boolean suppressNulls;
switch (incl) {
case NON_DEFAULT:
valueToSuppress = BeanUtil.getDefaultValue(_referredType);
suppressNulls = true;
if (valueToSuppress != null) {
if (valueToSuppress.getClass().isArray()) {
valueToSuppress = ArrayBuilders.getArrayComparator(valueToSuppress);
}
}
break;
case NON_ABSENT:
suppressNulls = true;
valueToSuppress = _referredType.isReferenceType() ? MARKER_FOR_EMPTY : null;
break;
case NON_EMPTY:
suppressNulls = true;
valueToSuppress = MARKER_FOR_EMPTY;
break;
case CUSTOM:
valueToSuppress = provider.includeFilterInstance(null, inclV.getContentFilter());
if (valueToSuppress == null) { // is this legal?
suppressNulls = true;
} else {
suppressNulls = provider.includeFilterSuppressNulls(valueToSuppress);
}
break;
case NON_NULL:
valueToSuppress = null;
suppressNulls = true;
break;
case ALWAYS: // default
default:
valueToSuppress = null;
suppressNulls = false;
break;
}
if ((_suppressableValue != valueToSuppress)
|| (_suppressNulls != suppressNulls)) {
refSer = refSer.withContentInclusion(valueToSuppress, suppressNulls);
}
}
}
}
return refSer;
}
protected boolean _useStatic(SerializerProvider provider, BeanProperty property,
JavaType referredType)
{
// First: no serializer for `Object.class`, must be dynamic
if (referredType.isJavaLangObject()) {
return false;
}
// but if type is final, might as well fetch
if (referredType.isFinal()) { // or should we allow annotation override? (only if requested...)
return true;
}
// also: if indicated by typing, should be considered static
if (referredType.useStaticType()) {
return true;
}
// if neither, maybe explicit annotation?
AnnotationIntrospector intr = provider.getAnnotationIntrospector();
if ((intr != null) && (property != null)) {
Annotated ann = property.getMember();
if (ann != null) {
JsonSerialize.Typing t = intr.findSerializationTyping(property.getMember());
if (t == JsonSerialize.Typing.STATIC) {
return true;
}
if (t == JsonSerialize.Typing.DYNAMIC) {
return false;
}
}
}
// and finally, may be forced by global static typing (unlikely...)
return provider.isEnabled(MapperFeature.USE_STATIC_TYPING);
}
/*
/**********************************************************
/* Accessors
/**********************************************************
*/
@Override
public boolean isEmpty(SerializerProvider provider, T value)
{
// First, absent value (note: null check is just sanity check here)
if (!_isValuePresent(value)) {
return true;
}
Object contents = _getReferenced(value);
if (contents == null) { // possible for explicitly contained `null`
return _suppressNulls;
}
if (_suppressableValue == null) {
return false;
}
JsonSerializer<Object> ser = _valueSerializer;
if (ser == null) {
try {
ser = _findCachedSerializer(provider, contents.getClass());
} catch (JsonMappingException e) { // nasty but necessary
throw new RuntimeJsonMappingException(e);
}
}
if (_suppressableValue == MARKER_FOR_EMPTY) {
return ser.isEmpty(provider, contents);
}
return _suppressableValue.equals(contents);
}
@Override
public boolean isUnwrappingSerializer() {
return (_unwrapper != null);
}
/**
* @since 2.9
*/
public JavaType getReferredType() {
return _referredType;
}
/*
/**********************************************************
/* Serialization methods
/**********************************************************
*/
@Override
public void serialize(T ref, JsonGenerator g, SerializerProvider provider)
throws IOException
{
Object value = _getReferencedIfPresent(ref);
if (value == null) {
if (_unwrapper == null) {
provider.defaultSerializeNull(g);
}
return;
}
JsonSerializer<Object> ser = _valueSerializer;
if (ser == null) {
ser = _findCachedSerializer(provider, value.getClass());
}
if (_valueTypeSerializer != null) {
ser.serializeWithType(value, g, provider, _valueTypeSerializer);
} else {
ser.serialize(value, g, provider);
}
}
@Override
public void serializeWithType(T ref,
JsonGenerator g, SerializerProvider provider,
TypeSerializer typeSer) throws IOException
{
Object value = _getReferencedIfPresent(ref);
if (value == null) {
if (_unwrapper == null) {
provider.defaultSerializeNull(g);
}
return;
}
// 19-Apr-2016, tatu: In order to basically "skip" the whole wrapper level
// (which is what non-polymorphic serialization does too), we will need
// to simply delegate call, I think, and NOT try to use it here.
// Otherwise apply type-prefix/suffix, then std serialize:
/*
typeSer.writeTypePrefixForScalar(ref, g);
serialize(ref, g, provider);
typeSer.writeTypeSuffixForScalar(ref, g);
*/
JsonSerializer<Object> ser = _valueSerializer;
if (ser == null) {
ser = _findCachedSerializer(provider, value.getClass());
}
ser.serializeWithType(value, g, provider, typeSer);
}
/*
/**********************************************************
/* Introspection support
/**********************************************************
*/
@Override
public void acceptJsonFormatVisitor(JsonFormatVisitorWrapper visitor, JavaType typeHint)
throws JsonMappingException
{
JsonSerializer<?> ser = _valueSerializer;
if (ser == null) {
ser = _findSerializer(visitor.getProvider(), _referredType, _property);
if (_unwrapper != null) {
ser = ser.unwrappingSerializer(_unwrapper);
}
}
ser.acceptJsonFormatVisitor(visitor, _referredType);
}
/*
/**********************************************************
/* Helper methods
/**********************************************************
*/
/**
* Helper method that encapsulates logic of retrieving and caching required
* serializer.
*/
private final JsonSerializer<Object> _findCachedSerializer(SerializerProvider provider,
Class<?> rawType) throws JsonMappingException
{
JsonSerializer<Object> ser = _dynamicSerializers.serializerFor(rawType);
if (ser == null) {
// NOTE: call this instead of `map._findAndAddDynamic(...)` (which in turn calls
// `findAndAddSecondarySerializer`) since we may need to apply unwrapper
// too, before caching. But calls made are the same
if (_referredType.hasGenericTypes()) {
// [databind#1673] Must ensure we will resolve all available type information
// so as not to miss generic declaration of, say, `List<GenericPojo>`...
JavaType fullType = provider.constructSpecializedType(_referredType, rawType);
// 23-Oct-2019, tatu: I _think_ we actually need to consider referenced
// type as "primary" to allow applying various handlers -- done since 2.11
ser = provider.findPrimaryPropertySerializer(fullType, _property);
} else {
ser = provider.findPrimaryPropertySerializer(rawType, _property);
}
if (_unwrapper != null) {
ser = ser.unwrappingSerializer(_unwrapper);
}
_dynamicSerializers = _dynamicSerializers.newWith(rawType, ser);
}
return ser;
}
private final JsonSerializer<Object> _findSerializer(SerializerProvider provider,
JavaType type, BeanProperty prop) throws JsonMappingException
{
// 13-Mar-2017, tatu: Used to call `findTypeValueSerializer()`, but contextualization
// not working for that case for some reason
// 15-Jan-2017, tatu: ... possibly because we need to access "secondary" serializer,
// not primary (primary being one for Reference type itself, not value)
// return provider.findTypedValueSerializer(type, true, prop);
return provider.findPrimaryPropertySerializer(type, prop);
}
}