All Downloads are FREE. Search and download functionalities are using the official Maven repository.

com.fasterxml.jackson.databind.ser.BeanPropertyWriter Maven / Gradle / Ivy

package com.fasterxml.jackson.databind.ser;

import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.util.HashMap;

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.SerializableString;
import com.fasterxml.jackson.core.io.SerializedString;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.annotation.JacksonStdImpl;
import com.fasterxml.jackson.databind.introspect.*;
import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonObjectFormatVisitor;
import com.fasterxml.jackson.databind.jsonschema.SchemaAware;
import com.fasterxml.jackson.databind.jsontype.TypeSerializer;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.fasterxml.jackson.databind.ser.impl.PropertySerializerMap;
import com.fasterxml.jackson.databind.ser.impl.UnwrappingBeanPropertyWriter;
import com.fasterxml.jackson.databind.ser.std.BeanSerializerBase;
import com.fasterxml.jackson.databind.util.Annotations;
import com.fasterxml.jackson.databind.util.NameTransformer;

/**
 * Base bean property handler class, which implements common parts of
 * reflection-based functionality for accessing a property value
 * and serializing it.
 *

* Note that current design tries to keep instances immutable (semi-functional * style); mostly because these instances are exposed to application * code and this is to reduce likelihood of data corruption and * synchronization issues. */ @JacksonStdImpl // since 2.6. NOTE: sub-classes typically are not public class BeanPropertyWriter extends PropertyWriter // which extends `ConcreteBeanPropertyBase` implements java.io.Serializable // since 2.6 { // As of 2.7 private static final long serialVersionUID = 1L; /** * Marker object used to indicate "do not serialize if empty" */ public final static Object MARKER_FOR_EMPTY = JsonInclude.Include.NON_EMPTY; /* /********************************************************** /* Basic property metadata: name, type, other /********************************************************** */ /** * Logical name of the property; will be used as the field name * under which value for the property is written. *

* NOTE: do NOT change name of this field; it is accessed by * Afterburner module (until 2.4; not directly from 2.5) * ALSO NOTE: ... and while it really ought to be `SerializableString`, * changing that is also binary-incompatible change. So nope. */ protected final SerializedString _name; /** * Wrapper name to use for this element, if any * * @since 2.2 */ protected final PropertyName _wrapperName; /** * Type property is declared to have, either in class definition * or associated annotations. */ protected final JavaType _declaredType; /** * Type to use for locating serializer; normally same as return * type of the accessor method, but may be overridden by annotations. */ protected final JavaType _cfgSerializationType; /** * Base type of the property, if the declared type is "non-trivial"; * meaning it is either a structured type (collection, map, array), * or parameterized. Used to retain type information about contained * type, which is mostly necessary if type meta-data is to be * included. */ protected JavaType _nonTrivialBaseType; /** * Annotations from context (most often, class that declares property, * or in case of sub-class serializer, from that sub-class) *

* NOTE: transient just to support JDK serializability; Annotations * do not serialize. At all. */ protected final transient Annotations _contextAnnotations; /* /********************************************************** /* Settings for accessing property value to serialize /********************************************************** */ /** * Member (field, method) that represents property and allows access * to associated annotations. */ protected final AnnotatedMember _member; /** * Accessor method used to get property value, for * method-accessible properties. * Null if and only if {@link #_field} is null. *

* `transient` (and non-final) only to support JDK serializability. */ protected transient Method _accessorMethod; /** * Field that contains the property value for field-accessible * properties. * Null if and only if {@link #_accessorMethod} is null. *

* `transient` (and non-final) only to support JDK serializability. */ protected transient Field _field; /* /********************************************************** /* Serializers needed /********************************************************** */ /** * Serializer to use for writing out the value: null if it can not * be known statically; non-null if it can. */ protected JsonSerializer _serializer; /** * Serializer used for writing out null values, if any: if null, * null values are to be suppressed. */ protected JsonSerializer _nullSerializer; /** * If property being serialized needs type information to be * included this is the type serializer to use. * Declared type (possibly augmented with annotations) of property * is used for determining exact mechanism to use (compared to * actual runtime type used for serializing actual state). */ protected TypeSerializer _typeSerializer; /** * In case serializer is not known statically (i.e. _serializer * is null), we will use a lookup structure for storing dynamically * resolved mapping from type(s) to serializer(s). */ protected transient PropertySerializerMap _dynamicSerializers; /* /********************************************************** /* Filtering /********************************************************** */ /** * Whether null values are to be suppressed (nothing written out if * value is null) or not. Note that this is a configuration value * during construction, and actual handling relies on setting * (or not) of {@link #_nullSerializer}. */ protected final boolean _suppressNulls; /** * Value that is considered default value of the property; used for * default-value-suppression if enabled. */ protected final Object _suppressableValue; /** * Alternate set of property writers used when view-based filtering * is available for the Bean. */ protected final Class[] _includeInViews; /* /********************************************************** /* Opaque internal data that bean serializer factory and /* bean serializers can add. /********************************************************** */ protected transient HashMap _internalSettings; /* /********************************************************** /* Construction, configuration /********************************************************** */ @SuppressWarnings("unchecked") public BeanPropertyWriter(BeanPropertyDefinition propDef, AnnotatedMember member, Annotations contextAnnotations, JavaType declaredType, JsonSerializer ser, TypeSerializer typeSer, JavaType serType, boolean suppressNulls, Object suppressableValue) { super(propDef); _member = member; _contextAnnotations = contextAnnotations; _name = new SerializedString(propDef.getName()); _wrapperName = propDef.getWrapperName(); _includeInViews = propDef.findViews(); _declaredType = declaredType; _serializer = (JsonSerializer) ser; _dynamicSerializers = (ser == null) ? PropertySerializerMap.emptyForProperties() : null; _typeSerializer = typeSer; _cfgSerializationType = serType; if (member instanceof AnnotatedField) { _accessorMethod = null; _field = (Field) member.getMember(); } else if (member instanceof AnnotatedMethod) { _accessorMethod = (Method) member.getMember(); _field = null; } else { // 01-Dec-2014, tatu: Used to be illegal, but now explicitly allowed for virtual props _accessorMethod = null; _field = null; } _suppressNulls = suppressNulls; _suppressableValue = suppressableValue; // this will be resolved later on, unless nulls are to be suppressed _nullSerializer = null; } /** * Constructor that may be of use to virtual properties, when there is need for * the zero-arg ("default") constructor, and actual initialization is done * after constructor call. * * @since 2.5 */ protected BeanPropertyWriter() { super(PropertyMetadata.STD_REQUIRED_OR_OPTIONAL); _member = null; _contextAnnotations = null; _name = null; _wrapperName = null; _includeInViews = null; _declaredType = null; _serializer = null; _dynamicSerializers = null; _typeSerializer = null; _cfgSerializationType = null; _accessorMethod = null; _field = null; _suppressNulls = false; _suppressableValue = null; _nullSerializer = null; } /** * "Copy constructor" to be used by filtering sub-classes */ protected BeanPropertyWriter(BeanPropertyWriter base) { this(base, base._name); } /** * @since 2.5 */ protected BeanPropertyWriter(BeanPropertyWriter base, PropertyName name) { super(base); /* 02-Dec-2014, tatu: This is a big mess, alas, what with dependency * to MapperConfig to encode, and Afterburner having heartburn * for SerializableString (vs SerializedString). * Hope it can be resolved/reworked in 2.6 timeframe, if not for 2.5 */ _name = new SerializedString(name.getSimpleName()); _wrapperName = base._wrapperName; _contextAnnotations = base._contextAnnotations; _declaredType = base._declaredType; _member = base._member; _accessorMethod = base._accessorMethod; _field = base._field; _serializer = base._serializer; _nullSerializer = base._nullSerializer; // one more thing: copy internal settings, if any if (base._internalSettings != null) { _internalSettings = new HashMap(base._internalSettings); } _cfgSerializationType = base._cfgSerializationType; _dynamicSerializers = base._dynamicSerializers; _suppressNulls = base._suppressNulls; _suppressableValue = base._suppressableValue; _includeInViews = base._includeInViews; _typeSerializer = base._typeSerializer; _nonTrivialBaseType = base._nonTrivialBaseType; } protected BeanPropertyWriter(BeanPropertyWriter base, SerializedString name) { super(base); _name = name; _wrapperName = base._wrapperName; _member = base._member; _contextAnnotations = base._contextAnnotations; _declaredType = base._declaredType; _accessorMethod = base._accessorMethod; _field = base._field; _serializer = base._serializer; _nullSerializer = base._nullSerializer; if (base._internalSettings != null) { _internalSettings = new HashMap(base._internalSettings); } _cfgSerializationType = base._cfgSerializationType; _dynamicSerializers = base._dynamicSerializers; _suppressNulls = base._suppressNulls; _suppressableValue = base._suppressableValue; _includeInViews = base._includeInViews; _typeSerializer = base._typeSerializer; _nonTrivialBaseType = base._nonTrivialBaseType; } public BeanPropertyWriter rename(NameTransformer transformer) { String newName = transformer.transform(_name.getValue()); if (newName.equals(_name.toString())) { return this; } return _new(PropertyName.construct(newName)); } /** * Overridable factory method used by sub-classes * * @since 2.6.0 */ protected BeanPropertyWriter _new(PropertyName newName) { return new BeanPropertyWriter(this, newName); } /** * Method called to set, reset or clear the configured type serializer * for property. * * @since 2.6 */ public void assignTypeSerializer(TypeSerializer typeSer) { _typeSerializer = typeSer; } /** * Method called to assign value serializer for property * * @since 2.0 */ public void assignSerializer(JsonSerializer ser) { // may need to disable check in future? if (_serializer != null && _serializer != ser) { throw new IllegalStateException("Can not override serializer"); } _serializer = ser; } /** * Method called to assign null value serializer for property * * @since 2.0 */ public void assignNullSerializer(JsonSerializer nullSer) { // may need to disable check in future? if (_nullSerializer != null && _nullSerializer != nullSer) { throw new IllegalStateException("Can not override null serializer"); } _nullSerializer = nullSer; } /** * Method called create an instance that handles details of unwrapping * contained value. */ public BeanPropertyWriter unwrappingWriter(NameTransformer unwrapper) { return new UnwrappingBeanPropertyWriter(this, unwrapper); } /** * Method called to define type to consider as "non-trivial" basetype, * needed for dynamic serialization resolution for complex (usually container) * types */ public void setNonTrivialBaseType(JavaType t) { _nonTrivialBaseType = t; } /* /********************************************************** /* JDK Serializability /********************************************************** */ /* Ideally would not require mutable state, and instead would re-create with * final settings. However, as things are, with sub-types and all, simplest * to just change Field/Method value directly. */ Object readResolve() { if (_member instanceof AnnotatedField) { _accessorMethod = null; _field = (Field) _member.getMember(); } else if (_member instanceof AnnotatedMethod) { _accessorMethod = (Method) _member.getMember(); _field = null; } if (_serializer == null) { _dynamicSerializers = PropertySerializerMap.emptyForProperties(); } return this; } /* /********************************************************** /* BeanProperty impl /********************************************************** */ // Note: also part of 'PropertyWriter' @Override public String getName() { return _name.getValue(); } // Note: also part of 'PropertyWriter' @Override public PropertyName getFullName() { // !!! TODO: impl properly return new PropertyName(_name.getValue()); } @Override public JavaType getType() { return _declaredType; } @Override public PropertyName getWrapperName() { return _wrapperName; } // Note: also part of 'PropertyWriter' @Override public A getAnnotation(Class acls) { return (_member == null) ? null : _member.getAnnotation(acls); } // Note: also part of 'PropertyWriter' @Override public A getContextAnnotation(Class acls) { return (_contextAnnotations == null) ? null : _contextAnnotations.get(acls); } @Override public AnnotatedMember getMember() { return _member; } // @since 2.3 -- needed so it can be overridden by unwrapping writer protected void _depositSchemaProperty(ObjectNode propertiesNode, JsonNode schemaNode) { propertiesNode.set(getName(), schemaNode); } /* /********************************************************** /* Managing and accessing of opaque internal settings /* (used by extensions) /********************************************************** */ /** * Method for accessing value of specified internal setting. * * @return Value of the setting, if any; null if none. */ public Object getInternalSetting(Object key) { return (_internalSettings == null) ? null : _internalSettings.get(key); } /** * Method for setting specific internal setting to given value * * @return Old value of the setting, if any (null if none) */ public Object setInternalSetting(Object key, Object value) { if (_internalSettings == null) { _internalSettings = new HashMap(); } return _internalSettings.put(key, value); } /** * Method for removing entry for specified internal setting. * * @return Existing value of the setting, if any (null if none) */ public Object removeInternalSetting(Object key) { Object removed = null; if (_internalSettings != null) { removed = _internalSettings.remove(key); // to reduce memory usage, let's also drop the Map itself, if empty if (_internalSettings.size() == 0) { _internalSettings = null; } } return removed; } /* /********************************************************** /* Accessors /********************************************************** */ public SerializableString getSerializedName() { return _name; } public boolean hasSerializer() { return _serializer != null; } public boolean hasNullSerializer() { return _nullSerializer != null; } /** * @since 2.6 */ public TypeSerializer getTypeSerializer() { return _typeSerializer; } /** * Accessor that will return true if this bean property has to support * "unwrapping"; ability to replace POJO structural wrapping with optional * name prefix and/or suffix (or in some cases, just removal of wrapper name). *

* Default implementation simply returns false. * * @since 2.3 */ public boolean isUnwrapping() { return false; } public boolean willSuppressNulls() { return _suppressNulls; } /** * Method called to check to see if this property has a name that would * conflict with a given name. * * @since 2.6 */ public boolean wouldConflictWithName(PropertyName name) { if (_wrapperName != null) { return _wrapperName.equals(name); } // Bit convoluted since our support for namespaces is spotty but: return name.hasSimpleName(_name.getValue()) && !name.hasNamespace(); } // Needed by BeanSerializer#getSchema public JsonSerializer getSerializer() { return _serializer; } public JavaType getSerializationType() { return _cfgSerializationType; } public Class getRawSerializationType() { return (_cfgSerializationType == null) ? null : _cfgSerializationType.getRawClass(); } /* public JavaType getFullPropertyType() { if (_accessorMethod != null) { return _accessorMethod.getType() } if (_field != null) { return _field.getType(); } return null; } */ /** * @deprecated Since 2.7, to be removed from 2.8, use {@link #getType()} instead. */ @Deprecated public Class getPropertyType() { if (_accessorMethod != null) { return _accessorMethod.getReturnType(); } if (_field != null) { return _field.getType(); } return null; } /** * Get the generic property type of this property writer. * * @return The property type, or null if not found. * * @deprecated Since 2.7, to be removed from 2.8, use {@link #getType()} instead. */ @Deprecated public Type getGenericPropertyType() { if (_accessorMethod != null) { return _accessorMethod.getGenericReturnType(); } if (_field != null) { return _field.getGenericType(); } return null; } public Class[] getViews() { return _includeInViews; } /* /********************************************************** /* PropertyWriter methods (serialization) /********************************************************** */ /** * Method called to access property that this bean stands for, from * within given bean, and to serialize it as a JSON Object field * using appropriate serializer. */ @Override public void serializeAsField(Object bean, JsonGenerator gen, SerializerProvider prov) throws Exception { // inlined 'get()' final Object value = (_accessorMethod == null) ? _field.get(bean) : _accessorMethod.invoke(bean); // Null handling is bit different, check that first if (value == null) { if (_nullSerializer != null) { gen.writeFieldName(_name); _nullSerializer.serialize(null, gen, prov); } return; } // then find serializer to use JsonSerializer ser = _serializer; if (ser == null) { Class cls = value.getClass(); PropertySerializerMap m = _dynamicSerializers; ser = m.serializerFor(cls); if (ser == null) { ser = _findAndAddDynamic(m, cls, prov); } } // and then see if we must suppress certain values (default, empty) if (_suppressableValue != null) { if (MARKER_FOR_EMPTY == _suppressableValue) { if (ser.isEmpty(prov, value)) { return; } } else if (_suppressableValue.equals(value)) { return; } } // For non-nulls: simple check for direct cycles if (value == bean) { // three choices: exception; handled by call; or pass-through if (_handleSelfReference(bean, gen, prov, ser)) { return; } } gen.writeFieldName(_name); if (_typeSerializer == null) { ser.serialize(value, gen, prov); } else { ser.serializeWithType(value, gen, prov, _typeSerializer); } } /** * Method called to indicate that serialization of a field was omitted * due to filtering, in cases where backend data format does not allow * basic omission. * * @since 2.3 */ @Override public void serializeAsOmittedField(Object bean, JsonGenerator gen, SerializerProvider prov) throws Exception { if (!gen.canOmitFields()) { gen.writeOmittedField(_name.getValue()); } } /** * Alternative to {@link #serializeAsField} that is used when a POJO * is serialized as JSON Array; the difference is that no field names * are written. * * @since 2.3 */ @Override public void serializeAsElement(Object bean, JsonGenerator gen, SerializerProvider prov) throws Exception { // inlined 'get()' final Object value = (_accessorMethod == null) ? _field.get(bean) : _accessorMethod.invoke(bean); if (value == null) { // nulls need specialized handling if (_nullSerializer != null) { _nullSerializer.serialize(null, gen, prov); } else { // can NOT suppress entries in tabular output gen.writeNull(); } return; } // otherwise find serializer to use JsonSerializer ser = _serializer; if (ser == null) { Class cls = value.getClass(); PropertySerializerMap map = _dynamicSerializers; ser = map.serializerFor(cls); if (ser == null) { ser = _findAndAddDynamic(map, cls, prov); } } // and then see if we must suppress certain values (default, empty) if (_suppressableValue != null) { if (MARKER_FOR_EMPTY == _suppressableValue) { if (ser.isEmpty(prov, value)) { // can NOT suppress entries in tabular output serializeAsPlaceholder(bean, gen, prov); return; } } else if (_suppressableValue.equals(value)) { // can NOT suppress entries in tabular output serializeAsPlaceholder(bean, gen, prov); return; } } // For non-nulls: simple check for direct cycles if (value == bean) { if (_handleSelfReference(bean, gen, prov, ser)) { return; } } if (_typeSerializer == null) { ser.serialize(value, gen, prov); } else { ser.serializeWithType(value, gen, prov, _typeSerializer); } } /** * Method called to serialize a placeholder used in tabular output when * real value is not to be included (is filtered out), but when we need * an entry so that field indexes will not be off. Typically this should * output null or empty String, depending on datatype. * * @since 2.1 */ @Override public void serializeAsPlaceholder(Object bean, JsonGenerator gen, SerializerProvider prov) throws Exception { if (_nullSerializer != null) { _nullSerializer.serialize(null, gen, prov); } else { gen.writeNull(); } } /* /********************************************************** /* PropertyWriter methods (schema generation) /********************************************************** */ // Also part of BeanProperty implementation @Override public void depositSchemaProperty(JsonObjectFormatVisitor v, SerializerProvider provider) throws JsonMappingException { if (v != null) { if (isRequired()) { v.property(this); } else { v.optionalProperty(this); } } } // // // Legacy support for JsonFormatVisitable /** * Attempt to add the output of the given {@link BeanPropertyWriter} in the given {@link ObjectNode}. * Otherwise, add the default schema {@link JsonNode} in place of the writer's output * * @param propertiesNode Node which the given property would exist within * @param provider Provider that can be used for accessing dynamic aspects of serialization * processing */ @Override @Deprecated public void depositSchemaProperty(ObjectNode propertiesNode, SerializerProvider provider) throws JsonMappingException { JavaType propType = getSerializationType(); // 03-Dec-2010, tatu: SchemaAware REALLY should use JavaType, but alas it doesn't... Type hint = (propType == null) ? getType() : propType.getRawClass(); JsonNode schemaNode; // Maybe it already has annotated/statically configured serializer? JsonSerializer ser = getSerializer(); if (ser == null) { // nope ser = provider.findValueSerializer(getType(), this); } boolean isOptional = !isRequired(); if (ser instanceof SchemaAware) { schemaNode = ((SchemaAware) ser).getSchema(provider, hint, isOptional) ; } else { schemaNode = com.fasterxml.jackson.databind.jsonschema.JsonSchema.getDefaultSchemaNode(); } _depositSchemaProperty(propertiesNode, schemaNode); } /* /********************************************************** /* Helper methods /********************************************************** */ protected JsonSerializer _findAndAddDynamic(PropertySerializerMap map, Class type, SerializerProvider provider) throws JsonMappingException { PropertySerializerMap.SerializerAndMapResult result; if (_nonTrivialBaseType != null) { JavaType t = provider.constructSpecializedType(_nonTrivialBaseType, type); result = map.findAndAddPrimarySerializer(t, provider, this); } else { result = map.findAndAddPrimarySerializer(type, provider, this); } // did we get a new map of serializers? If so, start using it if (map != result.map) { _dynamicSerializers = result.map; } return result.serializer; } /** * Method that can be used to access value of the property this * Object describes, from given bean instance. *

* Note: method is final as it should not need to be overridden -- rather, * calling method(s) ({@link #serializeAsField}) should be overridden * to change the behavior */ public final Object get(Object bean) throws Exception { return (_accessorMethod == null) ? _field.get(bean) : _accessorMethod.invoke(bean); } /** * Method called to handle a direct self-reference through this property. * Method can choose to indicate an error by throwing {@link JsonMappingException}; * fully handle serialization (and return true); or indicate that it should be * serialized normally (return false). *

* Default implementation will throw {@link JsonMappingException} if * {@link SerializationFeature#FAIL_ON_SELF_REFERENCES} is enabled; * or return false if it is disabled. * * @return True if method fully handled self-referential value; false if not (caller * is to handle it) or {@link JsonMappingException} if there is no way handle it */ protected boolean _handleSelfReference(Object bean, JsonGenerator gen, SerializerProvider prov, JsonSerializer ser) throws JsonMappingException { if (prov.isEnabled(SerializationFeature.FAIL_ON_SELF_REFERENCES) && !ser.usesObjectId()) { // 05-Feb-2013, tatu: Usually a problem, but NOT if we are handling // object id; this may be the case for BeanSerializers at least. // 13-Feb-2014, tatu: another possible ok case: custom serializer (something // OTHER than {@link BeanSerializerBase} if (ser instanceof BeanSerializerBase) { throw JsonMappingException.from(gen, "Direct self-reference leading to cycle"); } } return false; } @Override public String toString() { StringBuilder sb = new StringBuilder(40); sb.append("property '").append(getName()).append("' ("); if (_accessorMethod != null) { sb.append("via method ").append(_accessorMethod.getDeclaringClass().getName()).append("#").append(_accessorMethod.getName()); } else if (_field != null) { sb.append("field \"").append(_field.getDeclaringClass().getName()).append("#").append(_field.getName()); } else { sb.append("virtual"); } if (_serializer == null) { sb.append(", no static serializer"); } else { sb.append(", static serializer of type "+_serializer.getClass().getName()); } sb.append(')'); return sb.toString(); } }