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.core.JsonGenerator;
import com.fasterxml.jackson.core.io.SerializedString;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.introspect.AnnotatedField;
import com.fasterxml.jackson.databind.introspect.AnnotatedMember;
import com.fasterxml.jackson.databind.introspect.AnnotatedMethod;
import com.fasterxml.jackson.databind.introspect.BeanPropertyDefinition;
import com.fasterxml.jackson.databind.jsontype.TypeSerializer;
import com.fasterxml.jackson.databind.ser.impl.PropertySerializerMap;
import com.fasterxml.jackson.databind.ser.impl.UnwrappingBeanPropertyWriter;
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.
*<p>
* 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.
*/
public class BeanPropertyWriter
implements BeanProperty
{
/**
* Marker object used to indicate "do not serialize if empty"
*/
public final static Object MARKER_FOR_EMPTY = new Object();
/*
/**********************************************************
/* Settings for accessing property value to serialize
/**********************************************************
*/
/**
* Member (field, method) that represents property and allows access
* to associated annotations.
*/
protected final AnnotatedMember _member;
/**
* Annotations from context (most often, class that declares property,
* or in case of sub-class serializer, from that sub-class)
*/
protected final Annotations _contextAnnotations;
/**
* Type property is declared to have, either in class definition
* or associated annotations.
*/
protected final JavaType _declaredType;
/**
* Accessor method used to get property value, for
* method-accessible properties.
* Null if and only if {@link #_field} is null.
*/
protected final Method _accessorMethod;
/**
* Field that contains the property value for field-accessible
* properties.
* Null if and only if {@link #_accessorMethod} is null.
*/
protected final Field _field;
/*
/**********************************************************
/* Opaque internal data that bean serializer factory and
/* bean serializers can add.
/**********************************************************
*/
protected HashMap<Object,Object> _internalSettings;
/*
/**********************************************************
/* Serialization settings
/**********************************************************
*/
/**
* Logical name of the property; will be used as the field name
* under which value for the property is written.
*/
protected final SerializedString _name;
/**
* 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;
/**
* Serializer to use for writing out the value: null if it can not
* be known statically; non-null if it can.
*/
protected JsonSerializer<Object> _serializer;
/**
* Serializer used for writing out null values, if any: if null,
* null values are to be suppressed.
*/
protected JsonSerializer<Object> _nullSerializer;
/**
* In case serializer is not known statically (i.e. <code>_serializer</code>
* is null), we will use a lookup structure for storing dynamically
* resolved mapping from type(s) to serializer(s).
*/
protected PropertySerializerMap _dynamicSerializers;
/**
* Whether null values are to be suppressed (nothing written out if
* value is null) or not.
*/
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;
/**
* 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;
/**
* 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;
/*
/**********************************************************
/* Construction, configuration
/**********************************************************
*/
@SuppressWarnings("unchecked")
public BeanPropertyWriter(BeanPropertyDefinition propDef,
AnnotatedMember member, Annotations contextAnnotations,
JavaType declaredType,
JsonSerializer<?> ser, TypeSerializer typeSer, JavaType serType,
boolean suppressNulls, Object suppressableValue)
{
_member = member;
_contextAnnotations = contextAnnotations;
_name = new SerializedString(propDef.getName());
_declaredType = declaredType;
_serializer = (JsonSerializer<Object>) ser;
_dynamicSerializers = (ser == null) ? PropertySerializerMap.emptyMap() : 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 {
throw new IllegalArgumentException("Can not pass member of type "+member.getClass().getName());
}
_suppressNulls = suppressNulls;
_suppressableValue = suppressableValue;
_includeInViews = propDef.findViews();
// this will be resolved later on, unless nulls are to be suppressed
_nullSerializer = null;
}
/**
* "Copy constructor" to be used by filtering sub-classes
*/
protected BeanPropertyWriter(BeanPropertyWriter base) {
this(base, base._name);
}
protected BeanPropertyWriter(BeanPropertyWriter base, SerializedString name)
{
_name = name;
_member = base._member;
_contextAnnotations = base._contextAnnotations;
_declaredType = base._declaredType;
_accessorMethod = base._accessorMethod;
_field = base._field;
_serializer = base._serializer;
_nullSerializer = base._nullSerializer;
// one more thing: copy internal settings, if any (since 1.7)
if (base._internalSettings != null) {
_internalSettings = new HashMap<Object,Object>(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 BeanPropertyWriter(this, new SerializedString(newName));
}
/**
* Method called to assign value serializer for property
*
* @since 2.0
*/
public void assignSerializer(JsonSerializer<Object> 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<Object> 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;
}
/*
/**********************************************************
/* BeanProperty impl
/**********************************************************
*/
// @Override
public String getName() {
return _name.getValue();
}
// @Override
public JavaType getType() {
return _declaredType;
}
// @Override
public <A extends Annotation> A getAnnotation(Class<A> acls) {
return _member.getAnnotation(acls);
}
// @Override
public <A extends Annotation> A getContextAnnotation(Class<A> acls) {
return _contextAnnotations.get(acls);
}
// @Override
public AnnotatedMember getMember() {
return _member;
}
/*
/**********************************************************
/* 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)
{
if (_internalSettings == null) {
return null;
}
return _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<Object,Object>();
}
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 SerializedString getSerializedName() { return _name; }
public boolean hasSerializer() { return _serializer != null; }
public boolean hasNullSerializer() { return _nullSerializer != null; }
public boolean willSuppressNulls() { return _suppressNulls; }
// Needed by BeanSerializer#getSchema
public JsonSerializer<Object> getSerializer() {
return _serializer;
}
public JavaType getSerializationType() {
return _cfgSerializationType;
}
public Class<?> getRawSerializationType() {
return (_cfgSerializationType == null) ? null : _cfgSerializationType.getRawClass();
}
public Class<?> getPropertyType()
{
if (_accessorMethod != null) {
return _accessorMethod.getReturnType();
}
return _field.getType();
}
/**
* Get the generic property type of this property writer.
*
* @return The property type, or null if not found.
*/
public Type getGenericPropertyType()
{
if (_accessorMethod != null) {
return _accessorMethod.getGenericReturnType();
}
return _field.getGenericType();
}
public Class<?>[] getViews() { return _includeInViews; }
/*
/**********************************************************
/* Serialization functionality
/**********************************************************
*/
/**
* 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.
*/
public void serializeAsField(Object bean, JsonGenerator jgen, SerializerProvider prov)
throws Exception
{
Object value = get(bean);
// Null handling is bit different, check that first
if (value == null) {
if (_nullSerializer != null) {
jgen.writeFieldName(_name);
_nullSerializer.serialize(null, jgen, prov);
}
return;
}
// then find serializer to use
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);
}
}
// and then see if we must suppress certain values (default, empty)
if (_suppressableValue != null) {
if (MARKER_FOR_EMPTY == _suppressableValue) {
if (ser.isEmpty(value)) {
return;
}
} else if (_suppressableValue.equals(value)) {
return;
}
}
// For non-nulls: simple check for direct cycles
if (value == bean) {
_handleSelfReference(bean, ser);
}
jgen.writeFieldName(_name);
if (_typeSerializer == null) {
ser.serialize(value, jgen, prov);
} else {
ser.serializeWithType(value, jgen, prov, _typeSerializer);
}
}
/*
/**********************************************************
/* Helper methods
/**********************************************************
*/
protected JsonSerializer<Object> _findAndAddDynamic(PropertySerializerMap map,
Class<?> type, SerializerProvider provider) throws JsonMappingException
{
PropertySerializerMap.SerializerAndMapResult result;
if (_nonTrivialBaseType != null) {
JavaType t = provider.constructSpecializedType(_nonTrivialBaseType, type);
result = map.findAndAddSerializer(t, provider, this);
} else {
result = map.findAndAddSerializer(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.
*<p>
* 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
{
if (_accessorMethod != null) {
return _accessorMethod.invoke(bean);
}
return _field.get(bean);
}
protected void _handleSelfReference(Object bean, JsonSerializer<?> ser)
throws JsonMappingException
{
/* 05-Feb-2012, tatu: Usually a problem, but NOT if we are handling
* object id; this may be the case for BeanSerializers at least.
*/
if (ser.usesObjectId()) {
return;
}
throw new JsonMappingException("Direct self-reference leading to cycle");
}
@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 {
sb.append("field \"").append(_field.getDeclaringClass().getName()).append("#").append(_field.getName());
}
if (_serializer == null) {
sb.append(", no static serializer");
} else {
sb.append(", static serializer of type "+_serializer.getClass().getName());
}
sb.append(')');
return sb.toString();
}
}