Class MapSerializer

java.lang.Object
com.fasterxml.jackson.databind.JsonSerializer<Map<?,?>>
com.fasterxml.jackson.databind.ser.std.StdSerializer<Map<?,?>>
com.fasterxml.jackson.databind.ser.ContainerSerializer<Map<?,?>>
com.fasterxml.jackson.databind.ser.std.MapSerializer
All Implemented Interfaces:
JsonFormatVisitable, SchemaAware, ContextualSerializer, Serializable
public class MapSerializer extends ContainerSerializer<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:

  • Field Details

    • UNSPECIFIED_TYPE

      protected static final JavaType UNSPECIFIED_TYPE

    • MARKER_FOR_EMPTY

      public static final Object MARKER_FOR_EMPTY
      Since:
      2.9

    • _property

      protected final BeanProperty _property
      Map-valued property being serialized with this instance

    • _valueTypeIsStatic

      protected final boolean _valueTypeIsStatic
      Whether static types should be used for serialization of values or not (if not, dynamic runtime type is used)

    • _keyType

      protected final JavaType _keyType
      Declared type of keys

    • _valueType

      protected final JavaType _valueType
      Declared type of contained values

    • _keySerializer

      protected JsonSerializer<Object> _keySerializer
      Key serializer to use, if it can be statically determined

    • _valueSerializer

      protected JsonSerializer<Object> _valueSerializer
      Value serializer to use, if it can be statically determined

    • _valueTypeSerializer

      protected final TypeSerializer _valueTypeSerializer
      Type identifier serializer used for values, if any.

    • _dynamicValueSerializers

      protected PropertySerializerMap _dynamicValueSerializers
      If value type cannot be statically determined, mapping from runtime value types to serializers are stored in this object.

    • _ignoredEntries

      protected final Set<String> _ignoredEntries
      Set of entries to omit during serialization, if any

    • _includedEntries

      protected final Set<String> _includedEntries
      Set of entries to include during serialization, if null, it is ignored, empty will include nothing.
      Since:
      2.12

    • _filterId

      protected final Object _filterId
      Id of the property filter to use, if any; null if none.
      Since:
      2.3

    • _suppressableValue

      protected final Object _suppressableValue
      Value that indicates suppression mechanism to use for values contained; either "filter" (of which equals() is called), or marker value of MARKER_FOR_EMPTY, or null to indicate no filtering for non-null values. Note that inclusion value for Map instance itself is handled by caller (POJO property that refers to the Map value).
      Since:
      2.5

    • _suppressNulls

      protected final boolean _suppressNulls
      Flag that indicates what to do with `null` values, distinct from handling of _suppressableValue
      Since:
      2.9

    • _inclusionChecker

      protected final IgnorePropertiesUtil.Checker _inclusionChecker
      Helper object used for name-based filtering
      Since:
      2.12

    • _sortKeys

      protected final boolean _sortKeys
      Flag set if output is forced to be sorted by keys (usually due to annotation).
      Since:
      2.4

  • Constructor Details

  • Method Details

    • _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.
      Specified by:
      _withValueTypeSerializer in class ContainerSerializer<Map<?,?>>

    • withResolved

      public MapSerializer withResolved(BeanProperty property, JsonSerializer<?> keySerializer, JsonSerializer<?> valueSerializer, Set<String> ignored, Set<String> included, boolean sortKeys)
      Since:
      2.12

    • withResolved

      public MapSerializer withResolved(BeanProperty property, JsonSerializer<?> keySerializer, JsonSerializer<?> valueSerializer, Set<String> ignored, boolean sortKeys)
      Since:
      2.4

    • withFilterId

      public MapSerializer withFilterId(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<Map<?,?>>

    • withContentInclusion

      public MapSerializer withContentInclusion(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(Set<String> ignoredEntries, Set<String> includedEntries, JavaType mapType, boolean staticValueType, TypeSerializer vts, JsonSerializer<Object> keySerializer, JsonSerializer<Object> valueSerializer, Object filterId)
      Since:
      2.12

    • construct

      public static MapSerializer construct(Set<String> ignoredEntries, JavaType mapType, boolean staticValueType, TypeSerializer vts, JsonSerializer<Object> keySerializer, JsonSerializer<Object> valueSerializer, Object filterId)
      Since:
      2.8

    • _ensureOverride

      protected void _ensureOverride(String method)
      Since:
      2.9

    • _ensureOverride

      @Deprecated protected void _ensureOverride()
      Deprecated.
      Since:
      2.5

    • withContentInclusion

      @Deprecated public MapSerializer withContentInclusion(Object suppressableValue)
      Deprecated.
      since 2.9

    • construct

      @Deprecated public static MapSerializer construct(String[] ignoredList, JavaType mapType, boolean staticValueType, TypeSerializer vts, JsonSerializer<Object> keySerializer, JsonSerializer<Object> valueSerializer, 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<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.findContentValueSerializer(JavaType, BeanProperty).
      Specified by:
      getContentSerializer in class ContainerSerializer<Map<?,?>>

    • isEmpty

      public boolean isEmpty(SerializerProvider prov, 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<Map<?,?>>

    • hasSingleElement

      public boolean hasSingleElement(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<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(SerializerProvider, 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.

    • serialize

      public void serialize(Map<?,?> value, com.fasterxml.jackson.core.JsonGenerator gen, SerializerProvider provider) throws 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<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:
      IOException

    • serializeWithType

      public void serializeWithType(Map<?,?> value, com.fasterxml.jackson.core.JsonGenerator gen, SerializerProvider provider, TypeSerializer typeSer) throws 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<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:
      IOException

    • serializeWithoutTypeInfo

      public void serializeWithoutTypeInfo(Map<?,?> value, com.fasterxml.jackson.core.JsonGenerator gen, SerializerProvider provider) throws IOException
      General-purpose serialization for contents without writing object type. Will suppress, filter and use custom serializers.

      Public since it also is called by AnyGetterWriter.

      Throws:
      IOException
      Since:
      2.11

    • serializeFields

      public void serializeFields(Map<?,?> value, com.fasterxml.jackson.core.JsonGenerator gen, SerializerProvider provider) throws 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:
      IOException

    • serializeOptionalFields

      public void serializeOptionalFields(Map<?,?> value, com.fasterxml.jackson.core.JsonGenerator gen, SerializerProvider provider, Object suppressableValue) throws IOException
      Serialization method called when exclusion filtering needs to be applied.
      Throws:
      IOException

    • serializeFieldsUsing

      public void serializeFieldsUsing(Map<?,?> value, com.fasterxml.jackson.core.JsonGenerator gen, SerializerProvider provider, JsonSerializer<Object> ser) throws 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:
      IOException

    • serializeFilteredFields

      public void serializeFilteredFields(Map<?,?> value, com.fasterxml.jackson.core.JsonGenerator gen, SerializerProvider provider, PropertyFilter filter, Object suppressableValue) throws IOException
      Helper method used when we have a JSON Filter to use for potentially filtering out Map entries.
      Throws:
      IOException
      Since:
      2.5

    • serializeTypedFields

      public void serializeTypedFields(Map<?,?> value, com.fasterxml.jackson.core.JsonGenerator gen, SerializerProvider provider, Object suppressableValue) throws IOException
      Throws:
      IOException
      Since:
      2.5

    • serializeFilteredAnyProperties

      public void serializeFilteredAnyProperties(SerializerProvider provider, com.fasterxml.jackson.core.JsonGenerator gen, Object bean, Map<?,?> value, PropertyFilter filter, Object suppressableValue) throws 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:
      IOException
      Since:
      2.9

    • getSchema

      @Deprecated public JsonNode getSchema(SerializerProvider provider, Type typeHint)
      Deprecated.
      Since 2.15
      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<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<Map<?,?>>
      Parameters:
      typeHint - Type of element (entity like property) being visited
      Throws:
      JsonMappingException

    • _findAndAddDynamic

      protected final JsonSerializer<Object> _findAndAddDynamic(PropertySerializerMap map, Class<?> type, SerializerProvider provider) throws JsonMappingException
      Throws:
      JsonMappingException

    • _findAndAddDynamic

      protected final JsonSerializer<Object> _findAndAddDynamic(PropertySerializerMap map, JavaType type, SerializerProvider provider) throws JsonMappingException
      Throws:
      JsonMappingException

    • _orderEntries

      protected Map<?,?> _orderEntries(Map<?,?> input, com.fasterxml.jackson.core.JsonGenerator gen, SerializerProvider provider) throws IOException
      Throws:
      IOException

    • _hasNullKey

      protected boolean _hasNullKey(Map<?,?> input)
      Since:
      2.8.7

    • _writeNullKeyedEntry

      protected void _writeNullKeyedEntry(com.fasterxml.jackson.core.JsonGenerator gen, SerializerProvider provider, Object value) throws IOException
      Throws:
      IOException