package com.fasterxml.jackson.databind.ser.std; import com.fasterxml.jackson.core.JsonGenerator; import com.fasterxml.jackson.databind.*; import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonFormatVisitable; import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonFormatVisitorWrapper; import com.fasterxml.jackson.databind.jsonschema.SchemaAware; import com.fasterxml.jackson.databind.jsontype.TypeSerializer; import com.fasterxml.jackson.databind.ser.ContextualSerializer; import com.fasterxml.jackson.databind.ser.ResolvableSerializer; import com.fasterxml.jackson.databind.util.ClassUtil; import com.fasterxml.jackson.databind.util.Converter; import java.io.IOException; import java.lang.reflect.Type; /** * Serializer implementation where given Java type is first converted * to an intermediate "delegate type" (using a configured * {@link Converter}, and then this delegate value is serialized by Jackson. *<p> * Note that although types may be related, they must not be same; trying * to do this will result in an exception. * * @since 2.1 */ @SuppressWarnings("serial") public class StdDelegatingSerializer extends StdSerializer<Object> implements ContextualSerializer, ResolvableSerializer, JsonFormatVisitable, SchemaAware { protected final Converter<Object,?> _converter; /** * Fully resolved delegate type, with generic information if any available. */ protected final JavaType _delegateType; /** * Underlying serializer for type <code>T</code>. */ protected final JsonSerializer<Object> _delegateSerializer; /* /********************************************************** /* Life-cycle /********************************************************** */ @SuppressWarnings("unchecked") public StdDelegatingSerializer(Converter<?,?> converter) { super(Object.class); _converter = (Converter<Object,?>)converter; _delegateType = null; _delegateSerializer = null; } @SuppressWarnings("unchecked") public <T> StdDelegatingSerializer(Class<T> cls, Converter<T,?> converter) { super(cls, false); _converter = (Converter<Object,?>)converter; _delegateType = null; _delegateSerializer = null; } @SuppressWarnings("unchecked") public StdDelegatingSerializer(Converter<Object,?> converter, JavaType delegateType, JsonSerializer<?> delegateSerializer) { super(delegateType); _converter = converter; _delegateType = delegateType; _delegateSerializer = (JsonSerializer<Object>) delegateSerializer; } /** * Method used for creating resolved contextual instances. Must be * overridden when sub-classing. */ protected StdDelegatingSerializer withDelegate(Converter<Object,?> converter, JavaType delegateType, JsonSerializer<?> delegateSerializer) { ClassUtil.verifyMustOverride(StdDelegatingSerializer.class, this, "withDelegate"); return new StdDelegatingSerializer(converter, delegateType, delegateSerializer); } /* /********************************************************** /* Contextualization /********************************************************** */ @Override public void resolve(SerializerProvider provider) throws JsonMappingException { if ((_delegateSerializer != null) && (_delegateSerializer instanceof ResolvableSerializer)) { ((ResolvableSerializer) _delegateSerializer).resolve(provider); } } @Override public JsonSerializer<?> createContextual(SerializerProvider provider, BeanProperty property) throws JsonMappingException { JsonSerializer<?> delSer = _delegateSerializer; JavaType delegateType = _delegateType; if (delSer == null) { // Otherwise, need to locate serializer to delegate to. For that we need type information... if (delegateType == null) { delegateType = _converter.getOutputType(provider.getTypeFactory()); } // 02-Apr-2015, tatu: For "dynamic case", where type is only specified as // java.lang.Object (or missing generic), [databind#731] if (!delegateType.isJavaLangObject()) { delSer = provider.findValueSerializer(delegateType); } } if (delSer instanceof ContextualSerializer) { delSer = provider.handleSecondaryContextualization(delSer, property); } if (delSer == _delegateSerializer && delegateType == _delegateType) { return this; } return withDelegate(_converter, delegateType, delSer); } /* /********************************************************** /* Accessors /********************************************************** */ protected Converter<Object, ?> getConverter() { return _converter; } @Override public JsonSerializer<?> getDelegatee() { return _delegateSerializer; } /* /********************************************************** /* Serialization /********************************************************** */ @Override public void serialize(Object value, JsonGenerator gen, SerializerProvider provider) throws IOException { Object delegateValue = convertValue(value); // should we accept nulls? if (delegateValue == null) { provider.defaultSerializeNull(gen); return; } // 02-Apr-2015, tatu: As per [databind#731] may need to do dynamic lookup JsonSerializer<Object> ser = _delegateSerializer; if (ser == null) { ser = _findSerializer(delegateValue, provider); } ser.serialize(delegateValue, gen, provider); } @Override public void serializeWithType(Object value, JsonGenerator gen, SerializerProvider provider, TypeSerializer typeSer) throws IOException { /* 03-Oct-2012, tatu: This is actually unlikely to work ok... but for now, * let's give it a chance? */ Object delegateValue = convertValue(value); JsonSerializer<Object> ser = _delegateSerializer; if (ser == null) { ser = _findSerializer(value, provider); } ser.serializeWithType(delegateValue, gen, provider, typeSer); } @Override public boolean isEmpty(SerializerProvider prov, Object value) { Object delegateValue = convertValue(value); if (delegateValue == null) { return true; } if (_delegateSerializer == null) { // best we can do for now, too costly to look up return (value == null); } return _delegateSerializer.isEmpty(prov, delegateValue); } /* /********************************************************** /* Schema functionality /********************************************************** */ @Override public JsonNode getSchema(SerializerProvider provider, Type typeHint) throws JsonMappingException { if (_delegateSerializer instanceof SchemaAware) { return ((SchemaAware) _delegateSerializer).getSchema(provider, typeHint); } return super.getSchema(provider, typeHint); } @Override public JsonNode getSchema(SerializerProvider provider, Type typeHint, boolean isOptional) throws JsonMappingException { if (_delegateSerializer instanceof SchemaAware) { return ((SchemaAware) _delegateSerializer).getSchema(provider, typeHint, isOptional); } return super.getSchema(provider, typeHint); } @Override public void acceptJsonFormatVisitor(JsonFormatVisitorWrapper visitor, JavaType typeHint) throws JsonMappingException { /* 03-Sep-2012, tatu: Not sure if this can be made to really work * properly... but for now, try this: */ // 02-Apr-2015, tatu: For dynamic case, very little we can do if (_delegateSerializer != null) { _delegateSerializer.acceptJsonFormatVisitor(visitor, typeHint); } } /* /********************************************************** /* Overridable methods /********************************************************** */ /** * Method called to convert from source Java value into delegate * value (which will be serialized using standard Jackson serializer for delegate type) *<P> * The default implementation uses configured {@link Converter} to do * conversion. * * @param value Value to convert * * @return Result of conversion */ protected Object convertValue(Object value) { return _converter.convert(value); } /** * Helper method used for locating serializer to use in dynamic use case, where * actual type value gets converted to is not specified beyond basic * {@link java.lang.Object}, and where serializer needs to be located dynamically * based on actual value type. * * @since 2.6 */ protected JsonSerializer<Object> _findSerializer(Object value, SerializerProvider serializers) throws JsonMappingException { // NOTE: will NOT call contextualization return serializers.findValueSerializer(value.getClass()); } }