com.fasterxml.jackson.databind

Class SerializerProvider

  • Direct Known Subclasses:
    DefaultSerializerProvider


    public abstract class SerializerProvider
    extends DatabindContext
    Class that defines API used by ObjectMapper and JsonSerializers to obtain serializers capable of serializing instances of specific types; as well as the default implementation of the functionality.

    Provider handles caching aspects of serializer handling; all construction details are delegated to SerializerFactory instance.

    Object life-cycle is such that an initial instance ("blueprint") is created and referenced by ObjectMapper and ObjectWriter intances; but for actual usage, a configured instance is created by using a create method in sub-class DefaultSerializerProvider. Only this instance can be used for actual serialization calls; blueprint object is only to be used for creating instances.

    • Field Detail

      • CACHE_UNKNOWN_MAPPINGS

        protected static final boolean CACHE_UNKNOWN_MAPPINGS
        Setting for determining whether mappings for "unknown classes" should be cached for faster resolution. Usually this isn't needed, but maybe it is in some cases?
        See Also:
        Constant Field Values
      • DEFAULT_NULL_KEY_SERIALIZER

        public static final JsonSerializer<Object> DEFAULT_NULL_KEY_SERIALIZER
      • DEFAULT_UNKNOWN_SERIALIZER

        protected static final JsonSerializer<Object> DEFAULT_UNKNOWN_SERIALIZER
        Placeholder serializer used when java.lang.Object typed property is marked to be serialized.
        NOTE: starting with 2.6, this instance is NOT used for any other types, and separate instances are constructed for "empty" Beans.

        NOTE: changed to protected for 2.3; no need to be publicly available.

      • _config

        protected final SerializationConfig _config
        Serialization configuration to use for serialization processing.
      • _serializationView

        protected final Class<?> _serializationView
        View used for currently active serialization, if any. Only set for non-blueprint instances.
      • _serializerFactory

        protected final SerializerFactory _serializerFactory
        Factory used for constructing actual serializer instances. Only set for non-blueprint instances.
      • _serializerCache

        protected final SerializerCache _serializerCache
        Cache for doing type-to-value-serializer lookups.
      • _attributes

        protected transient ContextAttributes _attributes
        Lazily-constructed holder for per-call attributes. Only set for non-blueprint instances.
        Since:
        2.3
      • _unknownTypeSerializer

        protected JsonSerializer<Object> _unknownTypeSerializer
        Serializer that gets called for values of types for which no serializers can be constructed.

        The default serializer will simply thrown an exception.

      • _keySerializer

        protected JsonSerializer<Object> _keySerializer
        Serializer used to output non-null keys of Maps (which will get output as JSON Objects), if not null; if null, us the standard default key serializer.
      • _nullKeySerializer

        protected JsonSerializer<Object> _nullKeySerializer
        Serializer used to (try to) output a null key, due to an entry of Map having null key. The default implementation will throw an exception if this happens; alternative implementation (like one that would write an Empty String) can be defined.
      • _knownSerializers

        protected final ReadOnlyClassToSerializerMap _knownSerializers
        For fast lookups, we will have a local non-shared read-only map that contains serializers previously fetched.
      • _dateFormat

        protected DateFormat _dateFormat
        Lazily acquired and instantiated formatter object: initialized first time it is needed, reused afterwards. Used via instances (not blueprints), so that access need not be thread-safe.
      • _stdNullValueSerializer

        protected final boolean _stdNullValueSerializer
        Flag set to indicate that we are using vanilla null value serialization
        Since:
        2.3
    • Constructor Detail

      • SerializerProvider

        public SerializerProvider()
        Constructor for creating master (or "blue-print") provider object, which is only used as the template for constructing per-binding instances.
      • SerializerProvider

        protected SerializerProvider(SerializerProvider src,
                          SerializationConfig config,
                          SerializerFactory f)
        "Copy-constructor", used by sub-classes when creating actual non-blueprint instances to use.
        Parameters:
        src - Blueprint object used as the baseline for this instance
      • SerializerProvider

        protected SerializerProvider(SerializerProvider src)
        Copy-constructor used when making a copy of a blueprint instance.
        Since:
        2.5
    • Method Detail

      • setDefaultKeySerializer

        public void setDefaultKeySerializer(JsonSerializer<Object> ks)
        Method that can be used to specify serializer that will be used to write JSON property names matching null keys for Java Maps (which will throw an exception if try write such property name)
      • setNullValueSerializer

        public void setNullValueSerializer(JsonSerializer<Object> nvs)
        Method that can be used to specify serializer that will be used to write JSON values matching Java null values instead of default one (which simply writes JSON null).

        Note that you can get finer control over serializer to use by overriding findNullValueSerializer(com.fasterxml.jackson.databind.BeanProperty), which gets called once per each property.

      • setNullKeySerializer

        public void setNullKeySerializer(JsonSerializer<Object> nks)
        Method that can be used to specify serializer to use for serializing all non-null JSON property names, unless more specific key serializer is found (i.e. if not custom key serializer has been registered for Java type).

        Note that key serializer registration are different from value serializer registrations.

      • getActiveView

        public final Class<?> getActiveView()
        Description copied from class: DatabindContext
        Accessor for locating currently active view, if any; returns null if no view has been set.
        Specified by:
        getActiveView in class DatabindContext
      • canOverrideAccessModifiers

        public final boolean canOverrideAccessModifiers()
        Description copied from class: DatabindContext
        Convenience method for accessing serialization view in use (if any); equivalent to:
           getConfig().canOverrideAccessModifiers();
        
        Specified by:
        canOverrideAccessModifiers in class DatabindContext
      • isEnabled

        public final boolean isEnabled(MapperFeature feature)
        Description copied from class: DatabindContext
        Convenience method for checking whether specified serialization feature is enabled or not. Shortcut for:
          getConfig().isEnabled(feature);
        
        Specified by:
        isEnabled in class DatabindContext
      • getLocale

        public Locale getLocale()
        Method for accessing default Locale to use: convenience method for
           getConfig().getLocale();
        
        Specified by:
        getLocale in class DatabindContext
      • getTimeZone

        public TimeZone getTimeZone()
        Method for accessing default TimeZone to use: convenience method for
           getConfig().getTimeZone();
        
        Specified by:
        getTimeZone in class DatabindContext
      • getAttribute

        public Object getAttribute(Object key)
        Description copied from class: DatabindContext
        Method for accessing attributes available in this context. Per-call attributes have highest precedence; attributes set via ObjectReader or ObjectWriter have lower precedence.
        Specified by:
        getAttribute in class DatabindContext
        Parameters:
        key - Key of the attribute to get
        Returns:
        Value of the attribute, if any; null otherwise
      • setAttribute

        public SerializerProvider setAttribute(Object key,
                                      Object value)
        Description copied from class: DatabindContext
        Method for setting per-call value of given attribute. This will override any previously defined value for the attribute within this context.
        Specified by:
        setAttribute in class DatabindContext
        Parameters:
        key - Key of the attribute to set
        value - Value to set attribute to
        Returns:
        This context object, to allow chaining
      • isEnabled

        public final boolean isEnabled(SerializationFeature feature)
        Convenience method for checking whether specified serialization feature is enabled or not. Shortcut for:
          getConfig().isEnabled(feature);
        
      • hasSerializationFeatures

        public final boolean hasSerializationFeatures(int featureMask)
        "Bulk" access method for checking that all features specified by mask are enabled.
        Since:
        2.3
      • getFilterProvider

        public final FilterProvider getFilterProvider()
        Convenience method for accessing provider to find serialization filters used, equivalent to calling:
           getConfig().getFilterProvider();
        
      • findObjectId

        public abstract WritableObjectId findObjectId(Object forPojo,
                                    ObjectIdGenerator<?> generatorType)
        Method called to find the Object Id for given POJO, if one has been generated. Will always return a non-null Object; contents vary depending on whether an Object Id already exists or not.
      • findValueSerializer

        public JsonSerializer<Object> findValueSerializer(Class<?> valueType,
                                                 BeanProperty property)
                                                   throws JsonMappingException
        Method called to get hold of a serializer for a value of given type; or if no such serializer can be found, a default handler (which may do a best-effort generic serialization or just simply throw an exception when invoked).

        Note: this method is only called for non-null values; not for keys or null values. For these, check out other accessor methods.

        Note that serializers produced should NOT handle polymorphic serialization aspects; separate TypeSerializer is to be constructed by caller if and as necessary.

        Throws:
        JsonMappingException - if there are fatal problems with accessing suitable serializer; including that of not finding any serializer
      • findValueSerializer

        public JsonSerializer<Object> findValueSerializer(Class<?> valueType)
                                                   throws JsonMappingException
        Method variant used when we do NOT want contextualization to happen; it will need to be handled at a later point, but caller wants to be able to do that as needed; sometimes to avoid infinite loops
        Throws:
        JsonMappingException
        Since:
        2.5
      • findValueSerializer

        public JsonSerializer<Object> findValueSerializer(JavaType valueType)
                                                   throws JsonMappingException
        Method variant used when we do NOT want contextualization to happen; it will need to be handled at a later point, but caller wants to be able to do that as needed; sometimes to avoid infinite loops
        Throws:
        JsonMappingException
        Since:
        2.5
      • findPrimaryPropertySerializer

        public JsonSerializer<Object> findPrimaryPropertySerializer(JavaType valueType,
                                                           BeanProperty property)
                                                             throws JsonMappingException
        Similar to findValueSerializer(JavaType, BeanProperty), but used when finding "primary" property value serializer (one directly handling value of the property). Difference has to do with contextual resolution, and method(s) called: this method should only be called when caller is certain that this is the primary property value serializer.
        Parameters:
        property - Property that is being handled; will never be null, and its type has to match valueType parameter.
        Throws:
        JsonMappingException
        Since:
        2.3
      • findTypedValueSerializer

        public JsonSerializer<Object> findTypedValueSerializer(Class<?> valueType,
                                                      boolean cache,
                                                      BeanProperty property)
                                                        throws JsonMappingException
        Method called to locate regular serializer, matching type serializer, and if both found, wrap them in a serializer that calls both in correct sequence. This method is currently only used for root-level serializer handling to allow for simpler caching. A call can always be replaced by equivalent calls to access serializer and type serializer separately.
        Parameters:
        valueType - Type for purpose of locating a serializer; usually dynamic runtime type, but can also be static declared type, depending on configuration
        cache - Whether resulting value serializer should be cached or not; this is just a hint
        property - When creating secondary serializers, property for which serializer is needed: annotations of the property (or bean that contains it) may be checked to create contextual serializers.
        Throws:
        JsonMappingException
      • findTypedValueSerializer

        public JsonSerializer<Object> findTypedValueSerializer(JavaType valueType,
                                                      boolean cache,
                                                      BeanProperty property)
                                                        throws JsonMappingException
        Method called to locate regular serializer, matching type serializer, and if both found, wrap them in a serializer that calls both in correct sequence. This method is currently only used for root-level serializer handling to allow for simpler caching. A call can always be replaced by equivalent calls to access serializer and type serializer separately.
        Parameters:
        valueType - Declared type of value being serialized (which may not be actual runtime type); used for finding both value serializer and type serializer to use for adding polymorphic type (if any)
        cache - Whether resulting value serializer should be cached or not; this is just a hint
        property - When creating secondary serializers, property for which serializer is needed: annotations of the property (or bean that contains it) may be checked to create contextual serializers.
        Throws:
        JsonMappingException
      • getDefaultNullKeySerializer

        public JsonSerializer<Object> getDefaultNullKeySerializer()
        Since:
        2.0
      • getDefaultNullValueSerializer

        public JsonSerializer<Object> getDefaultNullValueSerializer()
        Since:
        2.0
      • findNullKeySerializer

        public JsonSerializer<Object> findNullKeySerializer(JavaType serializationType,
                                                   BeanProperty property)
                                                     throws JsonMappingException
        Method called to find a serializer to use for null values for given declared type. Note that type is completely based on declared type, since nulls in Java have no type and thus runtime type can not be determined.
        Throws:
        JsonMappingException
        Since:
        2.0
      • findNullValueSerializer

        public JsonSerializer<Object> findNullValueSerializer(BeanProperty property)
                                                       throws JsonMappingException
        Method called to get the serializer to use for serializing null values for specified property.

        Default implementation simply calls getDefaultNullValueSerializer(); can be overridden to add custom null serialization for properties of certain type or name. This gives method full granularity to basically override null handling for any specific property or class of properties.

        Throws:
        JsonMappingException
        Since:
        2.0
      • getUnknownTypeSerializer

        public JsonSerializer<Object> getUnknownTypeSerializer(Class<?> unknownType)
        Method called to get the serializer to use if provider can not determine an actual type-specific serializer to use; typically when none of SerializerFactory instances are able to construct a serializer.

        Typically, returned serializer will throw an exception, although alternatively ToStringSerializer could be returned as well.

        Parameters:
        unknownType - Type for which no serializer is found
      • isUnknownTypeSerializer

        public boolean isUnknownTypeSerializer(JsonSerializer<?> ser)
        Helper method called to see if given serializer is considered to be something returned by getUnknownTypeSerializer(java.lang.Class<?>), that is, something for which no regular serializer was found or constructed.
        Since:
        2.5
      • serializerInstance

        public abstract JsonSerializer<Object> serializerInstance(Annotated annotated,
                                                Object serDef)
                                                           throws JsonMappingException
        Method that can be called to construct and configure serializer instance, either given a Class to instantiate (with default constructor), or an uninitialized serializer instance. Either way, serialize will be properly resolved (via ResolvableSerializer) and/or contextualized (via ContextualSerializer) as necessary.
        Parameters:
        annotated - Annotated entity that contained definition
        serDef - Serializer definition: either an instance or class
        Throws:
        JsonMappingException
      • handleSecondaryContextualization

        public JsonSerializer<?> handleSecondaryContextualization(JsonSerializer<?> ser,
                                                         BeanProperty property)
                                                           throws JsonMappingException
        Method called for secondary property serializers (ones NOT directly created to serialize values of a POJO property but instead created as a dependant serializer -- such as value serializers for structured types, or serializers for root values) to handle details of resolving ContextualDeserializer with given property context. Given that these serializers are not directly related to given property (or, in case of root value property, to any property), annotations accessible may or may not be relevant.
        Parameters:
        property - Property for which serializer is used, if any; null when deserializing root values
        Throws:
        JsonMappingException
        Since:
        2.3
      • defaultSerializeField

        public final void defaultSerializeField(String fieldName,
                                 Object value,
                                 JsonGenerator gen)
                                         throws IOException
        Convenience method that will serialize given field with specified value. Value may be null. Serializer is done using the usual null) using standard serializer locating functionality.
        Throws:
        IOException
      • defaultSerializeDateValue

        public final void defaultSerializeDateValue(long timestamp,
                                     JsonGenerator gen)
                                             throws IOException
        Method that will handle serialization of Date(-like) values, using SerializationConfig settings to determine expected serialization behavior. Note: date here means "full" date, that is, date AND time, as per Java convention (and not date-only values like in SQL)
        Throws:
        IOException
      • defaultSerializeDateValue

        public final void defaultSerializeDateValue(Date date,
                                     JsonGenerator gen)
                                             throws IOException
        Method that will handle serialization of Date(-like) values, using SerializationConfig settings to determine expected serialization behavior. Note: date here means "full" date, that is, date AND time, as per Java convention (and not date-only values like in SQL)
        Throws:
        IOException
      • _findExplicitUntypedSerializer

        protected JsonSerializer<Object> _findExplicitUntypedSerializer(Class<?> runtimeType)
                                                                 throws JsonMappingException
        Method that will try to find a serializer, either from cache or by constructing one; but will not return an "unknown" serializer if this can not be done but rather returns null.
        Returns:
        Serializer if one can be found, null if not.
        Throws:
        JsonMappingException
      • _dateFormat

        protected final DateFormat _dateFormat()

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