com.fasterxml.jackson.databind.ser.std

Class MapSerializer

java.lang.Object

com.fasterxml.jackson.databind.JsonSerializer<T>

com.fasterxml.jackson.databind.ser.std.StdSerializer<T>

com.fasterxml.jackson.databind.ser.ContainerSerializer<java.util.Map<?,?>>

com.fasterxml.jackson.databind.ser.std.MapSerializer

All Implemented Interfaces:

JsonFormatVisitable, SchemaAware, ContextualSerializer, java.io.Serializable

public class MapSerializer
extends ContainerSerializer<java.util.Map<?,?>>
implements ContextualSerializer

Standard serializer implementation for serializing {link java.util.Map} types.

Note: about the only configurable setting currently is ability to filter out entries with specified names.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.fasterxml.jackson.databind.JsonSerializer

JsonSerializer.None

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.Object	MARKER_FOR_EMPTY

Method Summary

Modifier and Type	Method and Description
MapSerializer	_withValueTypeSerializer(TypeSerializer vts) Method that needs to be implemented to allow construction of a new serializer object with given TypeSerializer, used when addition type information is to be embedded.
void	acceptJsonFormatVisitor(JsonFormatVisitorWrapper visitor, JavaType typeHint) Default implementation specifies no format.
static MapSerializer	construct(java.util.Set<java.lang.String> ignoredEntries, JavaType mapType, boolean staticValueType, TypeSerializer vts, JsonSerializer<java.lang.Object> keySerializer, JsonSerializer<java.lang.Object> valueSerializer, java.lang.Object filterId)
static MapSerializer	construct(java.lang.String[] ignoredList, JavaType mapType, boolean staticValueType, TypeSerializer vts, JsonSerializer<java.lang.Object> keySerializer, JsonSerializer<java.lang.Object> valueSerializer, java.lang.Object filterId) Deprecated. Since 2.8 use the other overload
JsonSerializer<?>	createContextual(SerializerProvider provider, BeanProperty property) Method called to see if a different (or differently configured) serializer is needed to serialize values of specified property.
JsonSerializer<?>	getContentSerializer() Accessor for serializer used for serializing contents (List and array elements, Map values etc) of the container for which this serializer is used, if it is known statically.
JavaType	getContentType() Accessor for finding declared (static) element type for type this serializer is used for.
JsonSerializer<?>	getKeySerializer() Accessor for currently assigned key serializer.
JsonNode	getSchema(SerializerProvider provider, java.lang.reflect.Type typeHint) Default implementation simply claims type is "string"; usually overriden by custom serializers.
boolean	hasSingleElement(java.util.Map<?,?> value) Method called to determine if the given value (of type handled by this serializer) contains exactly one element.
boolean	isEmpty(SerializerProvider prov, java.util.Map<?,?> value) Method called to check whether given serializable value is considered "empty" value (for purposes of suppressing serialization of empty values).
void	serialize(java.util.Map<?,?> value, JsonGenerator gen, SerializerProvider provider) Method that can be called to ask implementation to serialize values of type this serializer handles.
void	serializeFields(java.util.Map<?,?> value, JsonGenerator gen, SerializerProvider provider) General-purpose serialization for contents, where we do not necessarily know the value serialization, but we do know that no value suppression is needed (which simplifies processing a bit)
void	serializeFieldsUsing(java.util.Map<?,?> value, JsonGenerator gen, SerializerProvider provider, JsonSerializer<java.lang.Object> ser) Method called to serialize fields, when the value type is statically known, so that value serializer is passed and does not need to be fetched from provider.
void	serializeFilteredAnyProperties(SerializerProvider provider, JsonGenerator gen, java.lang.Object bean, java.util.Map<?,?> value, PropertyFilter filter, java.lang.Object suppressableValue) Helper method used when we have a JSON Filter to use AND contents are "any properties" of a POJO.
void	serializeFilteredFields(java.util.Map<?,?> value, JsonGenerator gen, SerializerProvider provider, PropertyFilter filter, java.lang.Object suppressableValue) Helper method used when we have a JSON Filter to use for potentially filtering out Map entries.
void	serializeOptionalFields(java.util.Map<?,?> value, JsonGenerator gen, SerializerProvider provider, java.lang.Object suppressableValue) Serialization method called when exclusion filtering needs to be applied.
void	serializeTypedFields(java.util.Map<?,?> value, JsonGenerator gen, SerializerProvider provider, java.lang.Object suppressableValue)
void	serializeWithType(java.util.Map<?,?> value, JsonGenerator gen, SerializerProvider provider, TypeSerializer typeSer) Method that can be called to ask implementation to serialize values of type this serializer handles, using specified type serializer for embedding necessary type information.
MapSerializer	withContentInclusion(java.lang.Object suppressableValue) Deprecated. since 2.9
MapSerializer	withContentInclusion(java.lang.Object suppressableValue, boolean suppressNulls) Mutant factory for constructing an instance with different inclusion strategy for content (Map values).
MapSerializer	withFilterId(java.lang.Object filterId) Mutant factory method that is called if contextual configuration indicates that a specific filter (as specified by filterId) is to be used for serialization.
MapSerializer	withResolved(BeanProperty property, JsonSerializer<?> keySerializer, JsonSerializer<?> valueSerializer, java.util.Set<java.lang.String> ignored, boolean sortKeys)

Methods inherited from class com.fasterxml.jackson.databind.ser.ContainerSerializer

withValueTypeSerializer

Methods inherited from class com.fasterxml.jackson.databind.ser.std.StdSerializer

getSchema, handledType, wrapAndThrow, wrapAndThrow

Methods inherited from class com.fasterxml.jackson.databind.JsonSerializer

getDelegatee, isEmpty, isUnwrappingSerializer, properties, replaceDelegatee, unwrappingSerializer, usesObjectId

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MARKER_FOR_EMPTY

public static final java.lang.Object MARKER_FOR_EMPTY

Since:

2.9

Method Detail

_withValueTypeSerializer

public MapSerializer _withValueTypeSerializer(TypeSerializer vts)

Description copied from class: ContainerSerializer

Method that needs to be implemented to allow construction of a new serializer object with given TypeSerializer, used when addition type information is to be embedded.

withResolved

public MapSerializer withResolved(BeanProperty property,
                                  JsonSerializer<?> keySerializer,
                                  JsonSerializer<?> valueSerializer,
                                  java.util.Set<java.lang.String> ignored,
                                  boolean sortKeys)

Since:

2.4

withFilterId

public MapSerializer withFilterId(java.lang.Object filterId)

Description copied from class: JsonSerializer

Mutant factory method that is called if contextual configuration indicates that a specific filter (as specified by filterId) is to be used for serialization.

Default implementation simply returns this; sub-classes that do support filtering will need to create and return new instance if filter changes.

Overrides:

withFilterId in class JsonSerializer<java.util.Map<?,?>>

withContentInclusion

public MapSerializer withContentInclusion(java.lang.Object suppressableValue,
                                          boolean suppressNulls)

Mutant factory for constructing an instance with different inclusion strategy for content (Map values).

Since:

2.9

construct

public static MapSerializer construct(java.util.Set<java.lang.String> ignoredEntries,
                                      JavaType mapType,
                                      boolean staticValueType,
                                      TypeSerializer vts,
                                      JsonSerializer<java.lang.Object> keySerializer,
                                      JsonSerializer<java.lang.Object> valueSerializer,
                                      java.lang.Object filterId)

Since:

2.8

withContentInclusion

@Deprecated
public MapSerializer withContentInclusion(java.lang.Object suppressableValue)

Deprecated. since 2.9

construct

@Deprecated
public static MapSerializer construct(java.lang.String[] ignoredList,
                                                  JavaType mapType,
                                                  boolean staticValueType,
                                                  TypeSerializer vts,
                                                  JsonSerializer<java.lang.Object> keySerializer,
                                                  JsonSerializer<java.lang.Object> valueSerializer,
                                                  java.lang.Object filterId)

Deprecated. Since 2.8 use the other overload

Since:

2.3

createContextual

public JsonSerializer<?> createContextual(SerializerProvider provider,
                                          BeanProperty property)
                                   throws JsonMappingException

Description copied from interface: ContextualSerializer

Method called to see if a different (or differently configured) serializer is needed to serialize values of specified property. Note that instance that this method is called on is typically shared one and as a result method should NOT modify this instance but rather construct and return a new instance. This instance should only be returned as-is, in case it is already suitable for use.

Specified by:

createContextual in interface ContextualSerializer

Parameters:

provider - Serializer provider to use for accessing config, other serializers

property - Method or field that represents the property (and is used to access value to serialize). Should be available; but there may be cases where caller cannot provide it and null is passed instead (in which case impls usually pass 'this' serializer as is)

Returns:

Serializer to use for serializing values of specified property; may be this instance or a new instance.

Throws:

JsonMappingException

getContentType

public JavaType getContentType()

Description copied from class: ContainerSerializer

Accessor for finding declared (static) element type for type this serializer is used for.

Specified by:

getContentType in class ContainerSerializer<java.util.Map<?,?>>

getContentSerializer

public JsonSerializer<?> getContentSerializer()

Description copied from class: ContainerSerializer

Accessor for serializer used for serializing contents (List and array elements, Map values etc) of the container for which this serializer is used, if it is known statically. Note that for dynamic types this may return null; if so, caller has to instead use ContainerSerializer.getContentType() and SerializerProvider.findValueSerializer(java.lang.Class<?>, com.fasterxml.jackson.databind.BeanProperty).

Specified by:

getContentSerializer in class ContainerSerializer<java.util.Map<?,?>>

isEmpty

public boolean isEmpty(SerializerProvider prov,
                       java.util.Map<?,?> value)

Description copied from class: JsonSerializer

Method called to check whether given serializable value is considered "empty" value (for purposes of suppressing serialization of empty values).

Default implementation will consider only null values to be empty.

NOTE: replaces JsonSerializer.isEmpty(Object), which was deprecated in 2.5

Overrides:

isEmpty in class JsonSerializer<java.util.Map<?,?>>

hasSingleElement

public boolean hasSingleElement(java.util.Map<?,?> value)

Description copied from class: ContainerSerializer

Method called to determine if the given value (of type handled by this serializer) contains exactly one element.

Note: although it might seem sensible to instead define something like "getElementCount()" method, this would not work well for containers that do not keep track of size (like linked lists may not).

Note, too, that as of now (2.9) this method is only called by serializer itself; and specifically is not used for non-array/collection types like Map or Map.Entry instances.

Specified by:

hasSingleElement in class ContainerSerializer<java.util.Map<?,?>>

getKeySerializer

public JsonSerializer<?> getKeySerializer()

Accessor for currently assigned key serializer. Note that this may return null during construction of MapSerializer: depedencies are resolved during createContextual(com.fasterxml.jackson.databind.SerializerProvider, com.fasterxml.jackson.databind.BeanProperty) method (which can be overridden by custom implementations), but for some dynamic types, it is possible that serializer is only resolved during actual serialization.

Since:

2.0

serialize

public void serialize(java.util.Map<?,?> value,
                      JsonGenerator gen,
                      SerializerProvider provider)
               throws java.io.IOException

Description copied from class: JsonSerializer

Method that can be called to ask implementation to serialize values of type this serializer handles.

Specified by:

serialize in class StdSerializer<java.util.Map<?,?>>

Parameters:

value - Value to serialize; can not be null.

gen - Generator used to output resulting Json content

provider - Provider that can be used to get serializers for serializing Objects value contains, if any.

Throws:

java.io.IOException

serializeWithType

public void serializeWithType(java.util.Map<?,?> value,
                              JsonGenerator gen,
                              SerializerProvider provider,
                              TypeSerializer typeSer)
                       throws java.io.IOException

Description copied from class: JsonSerializer

Method that can be called to ask implementation to serialize values of type this serializer handles, using specified type serializer for embedding necessary type information.

Default implementation will throw UnsupportedOperationException to indicate that proper type handling needs to be implemented.

For simple datatypes written as a single scalar value (JSON String, Number, Boolean), implementation would look like:

  // note: method to call depends on whether this type is serialized as JSON scalar, object or Array!
  typeSer.writeTypePrefixForScalar(value, gen);
  serialize(value, gen, provider);
  typeSer.writeTypeSuffixForScalar(value, gen);

and implementations for type serialized as JSON Arrays or Objects would differ slightly, as START-ARRAY/END-ARRAY and START-OBJECT/END-OBJECT pairs need to be properly handled with respect to serializing of contents.

Overrides:

serializeWithType in class JsonSerializer<java.util.Map<?,?>>

Parameters:

value - Value to serialize; can not be null.

gen - Generator used to output resulting Json content

provider - Provider that can be used to get serializers for serializing Objects value contains, if any.

typeSer - Type serializer to use for including type information

Throws:

java.io.IOException

serializeFields

public void serializeFields(java.util.Map<?,?> value,
                            JsonGenerator gen,
                            SerializerProvider provider)
                     throws java.io.IOException

General-purpose serialization for contents, where we do not necessarily know the value serialization, but we do know that no value suppression is needed (which simplifies processing a bit)

Throws:

java.io.IOException

serializeOptionalFields

public void serializeOptionalFields(java.util.Map<?,?> value,
                                    JsonGenerator gen,
                                    SerializerProvider provider,
                                    java.lang.Object suppressableValue)
                             throws java.io.IOException

Serialization method called when exclusion filtering needs to be applied.

Throws:

java.io.IOException

serializeFieldsUsing

public void serializeFieldsUsing(java.util.Map<?,?> value,
                                 JsonGenerator gen,
                                 SerializerProvider provider,
                                 JsonSerializer<java.lang.Object> ser)
                          throws java.io.IOException

Method called to serialize fields, when the value type is statically known, so that value serializer is passed and does not need to be fetched from provider.

Throws:

java.io.IOException

serializeFilteredFields

public void serializeFilteredFields(java.util.Map<?,?> value,
                                    JsonGenerator gen,
                                    SerializerProvider provider,
                                    PropertyFilter filter,
                                    java.lang.Object suppressableValue)
                             throws java.io.IOException

Helper method used when we have a JSON Filter to use for potentially filtering out Map entries.

Throws:

java.io.IOException

Since:

2.5

serializeTypedFields

public void serializeTypedFields(java.util.Map<?,?> value,
                                 JsonGenerator gen,
                                 SerializerProvider provider,
                                 java.lang.Object suppressableValue)
                          throws java.io.IOException

Throws:

java.io.IOException

Since:

2.5

serializeFilteredAnyProperties

public void serializeFilteredAnyProperties(SerializerProvider provider,
                                           JsonGenerator gen,
                                           java.lang.Object bean,
                                           java.util.Map<?,?> value,
                                           PropertyFilter filter,
                                           java.lang.Object suppressableValue)
                                    throws java.io.IOException

Helper method used when we have a JSON Filter to use AND contents are "any properties" of a POJO.

Parameters:

bean - Enclosing POJO that has any-getter used to obtain "any properties"

Throws:

java.io.IOException

Since:

2.9

getSchema

public JsonNode getSchema(SerializerProvider provider,
                          java.lang.reflect.Type typeHint)

Description copied from class: StdSerializer

Default implementation simply claims type is "string"; usually overriden by custom serializers.

Specified by:

getSchema in interface SchemaAware

Overrides:

getSchema in class StdSerializer<java.util.Map<?,?>>

Parameters:

provider - The serializer provider.

typeHint - A hint about the type.

Returns:

Json-schema for this serializer.

acceptJsonFormatVisitor

public void acceptJsonFormatVisitor(JsonFormatVisitorWrapper visitor,
                                    JavaType typeHint)
                             throws JsonMappingException

Description copied from class: StdSerializer

Default implementation specifies no format. This behavior is usually overriden by custom serializers.

Specified by:

acceptJsonFormatVisitor in interface JsonFormatVisitable

Overrides:

acceptJsonFormatVisitor in class StdSerializer<java.util.Map<?,?>>

typeHint - Type of element (entity like property) being visited

Throws:

JsonMappingException