package com.fasterxml.jackson.databind.ser.impl;

import java.util.Iterator;
import java.util.Map.Entry;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.io.SerializedString;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonFormatVisitorWrapper;
import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonObjectFormatVisitor;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.fasterxml.jackson.databind.ser.BeanPropertyWriter;
import com.fasterxml.jackson.databind.util.NameTransformer;

Variant of BeanPropertyWriter which will handle unwrapping of JSON Object (including of properties of Object within surrounding JSON object, and not as sub-object).
/** * Variant of {@link BeanPropertyWriter} which will handle unwrapping * of JSON Object (including of properties of Object within surrounding * JSON object, and not as sub-object). */
public class UnwrappingBeanPropertyWriter extends BeanPropertyWriter implements java.io.Serializable { private static final long serialVersionUID = 1L;
Transformer used to add prefix and/or suffix for properties of unwrapped POJO.
/** * Transformer used to add prefix and/or suffix for properties * of unwrapped POJO. */
protected final NameTransformer _nameTransformer; /* /********************************************************** /* Life-cycle /********************************************************** */ public UnwrappingBeanPropertyWriter(BeanPropertyWriter base, NameTransformer unwrapper) { super(base); _nameTransformer = unwrapper; } protected UnwrappingBeanPropertyWriter(UnwrappingBeanPropertyWriter base, NameTransformer transformer, SerializedString name) { super(base, name); _nameTransformer = transformer; } @Override public UnwrappingBeanPropertyWriter rename(NameTransformer transformer) { String oldName = _name.getValue(); String newName = transformer.transform(oldName); // important: combine transformers: transformer = NameTransformer.chainedTransformer(transformer, _nameTransformer); return _new(transformer, new SerializedString(newName)); }
Overridable factory method used by sub-classes
Since:2.6.0
/** * Overridable factory method used by sub-classes * * @since 2.6.0 */
protected UnwrappingBeanPropertyWriter _new(NameTransformer transformer, SerializedString newName) { return new UnwrappingBeanPropertyWriter(this, transformer, newName); } /* /********************************************************** /* Overrides, public methods /********************************************************** */ @Override public boolean isUnwrapping() { return true; } @Override public void serializeAsField(Object bean, JsonGenerator gen, SerializerProvider prov) throws Exception { final Object value = get(bean); if (value == null) { // Hmmh. I assume we MUST pretty much suppress nulls, since we // can't really unwrap them... return; } JsonSerializer<Object> ser = _serializer; if (ser == null) { Class<?> cls = value.getClass(); PropertySerializerMap map = _dynamicSerializers; ser = map.serializerFor(cls); if (ser == null) { ser = _findAndAddDynamic(map, cls, prov); } } if (_suppressableValue != null) { if (MARKER_FOR_EMPTY == _suppressableValue) { if (ser.isEmpty(prov, value)) { return; } } else if (_suppressableValue.equals(value)) { return; } } // For non-nulls, first: simple check for direct cycles if (value == bean) { if (_handleSelfReference(bean, gen, prov, ser)) { return; } } // note: must verify we are using unwrapping serializer; if not, will write field name if (!ser.isUnwrappingSerializer()) { gen.writeFieldName(_name); } if (_typeSerializer == null) { ser.serialize(value, gen, prov); } else { ser.serializeWithType(value, gen, prov, _typeSerializer); } } // need to override as we must get unwrapping instance... @Override public void assignSerializer(JsonSerializer<Object> ser) { if (ser != null) { NameTransformer t = _nameTransformer; if (ser.isUnwrappingSerializer() // as per [databind#2060], need to also check this, in case someone writes // custom implementation that does not extend standard implementation: && (ser instanceof UnwrappingBeanSerializer)) { t = NameTransformer.chainedTransformer(t, ((UnwrappingBeanSerializer) ser)._nameTransformer); } ser = ser.unwrappingSerializer(t); } super.assignSerializer(ser); } /* /********************************************************** /* Overrides: schema generation /********************************************************** */ @Override public void depositSchemaProperty(final JsonObjectFormatVisitor visitor, SerializerProvider provider) throws JsonMappingException { JsonSerializer<Object> ser = provider .findValueSerializer(this.getType(), this) .unwrappingSerializer(_nameTransformer); if (ser.isUnwrappingSerializer()) { ser.acceptJsonFormatVisitor(new JsonFormatVisitorWrapper.Base(provider) { // an unwrapping serializer will always expect ObjectFormat, // hence, the other cases do not have to be implemented @Override public JsonObjectFormatVisitor expectObjectFormat(JavaType type) throws JsonMappingException { return visitor; } }, this.getType()); } else { super.depositSchemaProperty(visitor, provider); } } // Override needed to support legacy JSON Schema generator @Override protected void _depositSchemaProperty(ObjectNode propertiesNode, JsonNode schemaNode) { JsonNode props = schemaNode.get("properties"); if (props != null) { Iterator<Entry<String, JsonNode>> it = props.fields(); while (it.hasNext()) { Entry<String,JsonNode> entry = it.next(); String name = entry.getKey(); if (_nameTransformer != null) { name = _nameTransformer.transform(name); } propertiesNode.set(name, entry.getValue()); } } } /* /********************************************************** /* Overrides: internal, other /********************************************************** */ // need to override as we must get unwrapping instance... @Override protected JsonSerializer<Object> _findAndAddDynamic(PropertySerializerMap map, Class<?> type, SerializerProvider provider) throws JsonMappingException { JsonSerializer<Object> serializer; if (_nonTrivialBaseType != null) { JavaType subtype = provider.constructSpecializedType(_nonTrivialBaseType, type); serializer = provider.findValueSerializer(subtype, this); } else { serializer = provider.findValueSerializer(type, this); } NameTransformer t = _nameTransformer; if (serializer.isUnwrappingSerializer() // as per [databind#2060], need to also check this, in case someone writes // custom implementation that does not extend standard implementation: && (serializer instanceof UnwrappingBeanSerializer)) { t = NameTransformer.chainedTransformer(t, ((UnwrappingBeanSerializer) serializer)._nameTransformer); } serializer = serializer.unwrappingSerializer(t); _dynamicSerializers = _dynamicSerializers.newWith(type, serializer); return serializer; } }