com.fasterxml.jackson.databind

Class ObjectMapper

  • java.lang.Object
    • com.fasterxml.jackson.core.TreeCodec
      • com.fasterxml.jackson.core.ObjectCodec
        • com.fasterxml.jackson.databind.ObjectMapper
  • All Implemented Interfaces:
    com.fasterxml.jackson.core.Versioned, Serializable
    Direct Known Subclasses:
    JsonMapper

    public class ObjectMapper
extends com.fasterxml.jackson.core.ObjectCodec
implements com.fasterxml.jackson.core.Versioned, Serializable
    ObjectMapper provides functionality for reading and writing JSON, either to and from basic POJOs (Plain Old Java Objects), or to and from a general-purpose JSON Tree Model (JsonNode), as well as related functionality for performing conversions. It is also highly customizable to work both with different styles of JSON content, and to support more advanced Object concepts such as polymorphism and Object identity. ObjectMapper also acts as a factory for more advanced ObjectReader and ObjectWriter classes. Mapper (and ObjectReaders, ObjectWriters it constructs) will use instances of JsonParser and JsonGenerator for implementing actual reading/writing of JSON. Note that although most read and write methods are exposed through this class, some of the functionality is only exposed via ObjectReader and ObjectWriter: specifically, reading/writing of longer sequences of values is only available through ObjectReader.readValues(InputStream) and ObjectWriter.writeValues(OutputStream).

    Simplest usage is of form: 

      final ObjectMapper mapper = new ObjectMapper(); // can use static singleton, inject: just make sure to reuse!
  MyValue value = new MyValue();
  // ... and configure
  File newState = new File("my-stuff.json");
  mapper.writeValue(newState, value); // writes JSON serialization of MyValue instance
  // or, read
  MyValue older = mapper.readValue(new File("my-older-stuff.json"), MyValue.class);

  // Or if you prefer JSON Tree representation:
  JsonNode root = mapper.readTree(newState);
  // and find values by, for example, using a JsonPointer expression:
  int age = root.at("/personal/age").getValueAsInt();

    The main conversion API is defined in ObjectCodec, so that implementation details of this class need not be exposed to streaming parser and generator classes. Usage via ObjectCodec is, however, usually only for cases where dependency to ObjectMapper is either not possible (from Streaming API), or undesireable (when only relying on Streaming API).

    Mapper instances are fully thread-safe provided that ALL configuration of the instance occurs before ANY read or write calls. If configuration of a mapper instance is modified after first usage, changes may or may not take effect, and configuration calls themselves may fail. If you need to use different configuration, you have two main possibilities:

    • Construct and use ObjectReader for reading, ObjectWriter for writing. Both types are fully immutable and you can freely create new instances with different configuration using either factory methods of ObjectMapper, or readers/writers themselves. Construction of new ObjectReaders and ObjectWriters is a very light-weight operation so it is usually appropriate to create these on per-call basis, as needed, for configuring things like optional indentation of JSON.
    • If the specific kind of configurability is not available via ObjectReader and ObjectWriter, you may need to use multiple ObjectMapper instead (for example: you cannot change mix-in annotations on-the-fly; or, set of custom (de)serializers). To help with this usage, you may want to use method copy() which creates a clone of the mapper with specific configuration, and allows configuration of the copied instance before it gets used. Note that copy() operation is as expensive as constructing a new ObjectMapper instance: if possible, you should still pool and reuse mappers if you intend to use them for multiple operations.

    Note on caching: root-level deserializers are always cached, and accessed using full (generics-aware) type information. This is different from caching of referenced types, which is more limited and is done only for a subset of all deserializer types. The main reason for difference is that at root-level there is no incoming reference (and hence no referencing property, no referral information or annotations to produce differing deserializers), and that the performance impact greatest at root level (since it'll essentially cache the full graph of deserializers involved).

    Notes on security: use "default typing" feature (see enableDefaultTyping()) is a potential security risk, if used with untrusted content (content generated by untrusted external parties). If so, you may want to construct a custom TypeResolverBuilder implementation to limit possible types to instantiate, (using setDefaultTyping(com.fasterxml.jackson.databind.jsontype.TypeResolverBuilder<?>)).

    See Also:
    Serialized Form

    • Field Detail

      • DEFAULT_ANNOTATION_INTROSPECTOR

        protected static final AnnotationIntrospector DEFAULT_ANNOTATION_INTROSPECTOR

      • DEFAULT_BASE

        protected static final BaseSettings DEFAULT_BASE
        Base settings contain defaults used for all ObjectMapper instances.

      • _jsonFactory

        protected final com.fasterxml.jackson.core.JsonFactory _jsonFactory
        Factory used to create JsonParser and JsonGenerator instances as necessary.

      • _typeFactory

        protected TypeFactory _typeFactory
        Specific factory used for creating JavaType instances; needed to allow modules to add more custom type handling (mostly to support types of non-Java JVM languages)

      • _injectableValues

        protected InjectableValues _injectableValues
        Provider for values to inject in deserialized POJOs.

      • _subtypeResolver

        protected SubtypeResolver _subtypeResolver
        Thing used for registering sub-types, resolving them to super/sub-types as needed.

      • _configOverrides

        protected final ConfigOverrides _configOverrides
        Currently active per-type configuration overrides, accessed by declared type of property.
        Since:
        2.9

      • _coercionConfigs

        protected final CoercionConfigs _coercionConfigs
        Current set of coercion configuration definitions that define allowed (and not allowed) coercions from secondary shapes.
        Since:
        2.12

      • _mixIns

        protected SimpleMixInResolver _mixIns
        Mapping that defines how to apply mix-in annotations: key is the type to received additional annotations, and value is the type that has annotations to "mix in".

        Annotations associated with the value classes will be used to override annotations of the key class, associated with the same field or method. They can be further masked by sub-classes: you can think of it as injecting annotations between the target class and its sub-classes (or interfaces)

        Since:
        2.6 (earlier was a simple Map

      • _serializationConfig

        protected SerializationConfig _serializationConfig
        Configuration object that defines basic global settings for the serialization process

      • _serializerFactory

        protected SerializerFactory _serializerFactory
        Serializer factory used for constructing serializers.

      • _deserializationConfig

        protected DeserializationConfig _deserializationConfig
        Configuration object that defines basic global settings for the serialization process

      • _deserializationContext

        protected DefaultDeserializationContext _deserializationContext
        Blueprint context object; stored here to allow custom sub-classes. Contains references to objects needed for deserialization construction (cache, factory).

      • _rootDeserializers

        protected final ConcurrentHashMap<JavaType,JsonDeserializer<Object>> _rootDeserializers
        We will use a separate main-level Map for keeping track of root-level deserializers. This is where most successful cache lookups get resolved. Map will contain resolvers for all kinds of types, including container types: this is different from the component cache which will only cache bean deserializers.

        Given that we don't expect much concurrency for additions (should very quickly converge to zero after startup), let's explicitly define a low concurrency setting.

        These may are either "raw" deserializers (when no type information is needed for base type), or type-wrapped deserializers (if it is needed)

    • Constructor Detail

      • ObjectMapper

        public ObjectMapper()
        Default constructor, which will construct the default JsonFactory as necessary, use SerializerProvider as its SerializerProvider, and BeanSerializerFactory as its SerializerFactory. This means that it can serialize all standard JDK types, as well as regular Java Beans (based on method names and Jackson-specific annotations), but does not support JAXB annotations.

      • ObjectMapper

        public ObjectMapper(com.fasterxml.jackson.core.JsonFactory jf)
        Constructs instance that uses specified JsonFactory for constructing necessary JsonParsers and/or JsonGenerators.

      • ObjectMapper

        protected ObjectMapper(ObjectMapper src)
        Copy-constructor, mostly used to support copy().
        Since:
        2.1

      • ObjectMapper

        public ObjectMapper(com.fasterxml.jackson.core.JsonFactory jf,
                    DefaultSerializerProvider sp,
                    DefaultDeserializationContext dc)
        Constructs instance that uses specified JsonFactory for constructing necessary JsonParsers and/or JsonGenerators, and uses given providers for accessing serializers and deserializers.
        Parameters:
        jf - JsonFactory to use: if null, a new MappingJsonFactory will be constructed
        sp - SerializerProvider to use: if null, a SerializerProvider will be constructed
        dc - Blueprint deserialization context instance to use for creating actual context objects; if null, will construct standard DeserializationContext

    • Method Detail

      • defaultClassIntrospector

        protected ClassIntrospector defaultClassIntrospector()
        Overridable helper method used to construct default ClassIntrospector to use.
        Since:
        2.5

      • copy

        public ObjectMapper copy()
        Method for creating a new ObjectMapper instance that has same initial configuration as this instance. Note that this also requires making a copy of the underlying JsonFactory instance.

        Method is typically used when multiple, differently configured mappers are needed. Although configuration is shared, cached serializers and deserializers are NOT shared, which means that the new instance may be re-configured before use; meaning that it behaves the same way as if an instance was constructed from scratch.

        Since:
        2.1

      • _checkInvalidCopy

        protected void _checkInvalidCopy(Class<?> exp)
        Since:
        2.1

      • _newWriter

        protected ObjectWriter _newWriter(SerializationConfig config,
                                  com.fasterxml.jackson.core.FormatSchema schema)
        Factory method sub-classes must override, to produce ObjectWriter instances of proper sub-type
        Since:
        2.5

      • version

        public com.fasterxml.jackson.core.Version version()
        Method that will return version information stored in and read from jar that contains this class.
        Specified by:
        version in interface com.fasterxml.jackson.core.Versioned
        Specified by:
        version in class com.fasterxml.jackson.core.ObjectCodec

      • registerModule

        public ObjectMapper registerModule(Module module)
        Method for registering a module that can extend functionality provided by this mapper; for example, by adding providers for custom serializers and deserializers.
        Parameters:
        module - Module to register

      • registerModules

        public ObjectMapper registerModules(Module... modules)
        Convenience method for registering specified modules in order; functionally equivalent to: 
           for (Module module : modules) {
      registerModule(module);
   }
        Since:
        2.2

      • registerModules

        public ObjectMapper registerModules(Iterable<? extends Module> modules)
        Convenience method for registering specified modules in order; functionally equivalent to: 
           for (Module module : modules) {
      registerModule(module);
   }
        Since:
        2.2

      • getRegisteredModuleIds

        public Set<Object> getRegisteredModuleIds()
        The set of Module typeIds that are registered in this ObjectMapper. By default the typeId for a module is it's full class name (see Module.getTypeId()).
        Since:
        2.9.6

      • findModules

        public static List<Module> findModules()
        Method for locating available methods, using JDK ServiceLoader facility, along with module-provided SPI.

        Note that method does not do any caching, so calls should be considered potentially expensive.

        Since:
        2.2

      • findModules

        public static List<Module> findModules(ClassLoader classLoader)
        Method for locating available methods, using JDK ServiceLoader facility, along with module-provided SPI.

        Note that method does not do any caching, so calls should be considered potentially expensive.

        Since:
        2.2

      • findAndRegisterModules

        public ObjectMapper findAndRegisterModules()
        Convenience method that is functionally equivalent to: mapper.registerModules(mapper.findModules());

        As with findModules(), no caching is done for modules, so care needs to be taken to either create and share a single mapper instance; or to cache introspected set of modules.

        Since:
        2.2

      • createGenerator

        public com.fasterxml.jackson.core.JsonGenerator createGenerator(OutputStream out)
                                                         throws IOException
        Factory method for constructing properly initialized JsonGenerator to write content using specified OutputStream. Generator is not managed (or "owned") by mapper: caller is responsible for properly closing it once content generation is complete.
        Throws:
        IOException
        Since:
        2.11

      • createGenerator

        public com.fasterxml.jackson.core.JsonGenerator createGenerator(OutputStream out,
                                                                com.fasterxml.jackson.core.JsonEncoding enc)
                                                         throws IOException
        Factory method for constructing properly initialized JsonGenerator to write content using specified OutputStream and encoding. Generator is not managed (or "owned") by mapper: caller is responsible for properly closing it once content generation is complete.
        Throws:
        IOException
        Since:
        2.11

      • createGenerator

        public com.fasterxml.jackson.core.JsonGenerator createGenerator(Writer w)
                                                         throws IOException
        Factory method for constructing properly initialized JsonGenerator to write content using specified Writer. Generator is not managed (or "owned") by mapper: caller is responsible for properly closing it once content generation is complete.
        Throws:
        IOException
        Since:
        2.11

      • createGenerator

        public com.fasterxml.jackson.core.JsonGenerator createGenerator(File outputFile,
                                                                com.fasterxml.jackson.core.JsonEncoding enc)
                                                         throws IOException
        Factory method for constructing properly initialized JsonGenerator to write content to specified File, using specified encoding. Generator is not managed (or "owned") by mapper: caller is responsible for properly closing it once content generation is complete.
        Throws:
        IOException
        Since:
        2.11

      • createGenerator

        public com.fasterxml.jackson.core.JsonGenerator createGenerator(DataOutput out)
                                                         throws IOException
        Factory method for constructing properly initialized JsonGenerator to write content using specified DataOutput. Generator is not managed (or "owned") by mapper: caller is responsible for properly closing it once content generation is complete.
        Throws:
        IOException
        Since:
        2.11

      • createParser

        public com.fasterxml.jackson.core.JsonParser createParser(File src)
                                                   throws IOException
        Factory method for constructing properly initialized JsonParser to read content from specified File. Parser is not managed (or "owned") by ObjectMapper: caller is responsible for properly closing it once content reading is complete.
        Throws:
        IOException
        Since:
        2.11

      • createParser

        public com.fasterxml.jackson.core.JsonParser createParser(URL src)
                                                   throws IOException
        Factory method for constructing properly initialized JsonParser to read content from specified File. Parser is not managed (or "owned") by ObjectMapper: caller is responsible for properly closing it once content reading is complete.
        Throws:
        IOException
        Since:
        2.11

      • createParser

        public com.fasterxml.jackson.core.JsonParser createParser(InputStream in)
                                                   throws IOException
        Factory method for constructing properly initialized JsonParser to read content using specified InputStream. Parser is not managed (or "owned") by ObjectMapper: caller is responsible for properly closing it once content reading is complete.
        Throws:
        IOException
        Since:
        2.11

      • createParser

        public com.fasterxml.jackson.core.JsonParser createParser(Reader r)
                                                   throws IOException
        Factory method for constructing properly initialized JsonParser to read content using specified Reader. Parser is not managed (or "owned") by ObjectMapper: caller is responsible for properly closing it once content reading is complete.
        Throws:
        IOException
        Since:
        2.11

      • createParser

        public com.fasterxml.jackson.core.JsonParser createParser(byte[] content)
                                                   throws IOException
        Factory method for constructing properly initialized JsonParser to read content from specified byte array. Parser is not managed (or "owned") by ObjectMapper: caller is responsible for properly closing it once content reading is complete.
        Throws:
        IOException
        Since:
        2.11

      • createParser

        public com.fasterxml.jackson.core.JsonParser createParser(byte[] content,
                                                          int offset,
                                                          int len)
                                                   throws IOException
        Factory method for constructing properly initialized JsonParser to read content from specified byte array. Parser is not managed (or "owned") by ObjectMapper: caller is responsible for properly closing it once content reading is complete.
        Throws:
        IOException
        Since:
        2.11

      • createParser

        public com.fasterxml.jackson.core.JsonParser createParser(String content)
                                                   throws IOException
        Factory method for constructing properly initialized JsonParser to read content from specified String. Parser is not managed (or "owned") by ObjectMapper: caller is responsible for properly closing it once content reading is complete.
        Throws:
        IOException
        Since:
        2.11

      • createParser

        public com.fasterxml.jackson.core.JsonParser createParser(char[] content)
                                                   throws IOException
        Factory method for constructing properly initialized JsonParser to read content from specified character array Parser is not managed (or "owned") by ObjectMapper: caller is responsible for properly closing it once content reading is complete.
        Throws:
        IOException
        Since:
        2.11

      • createParser

        public com.fasterxml.jackson.core.JsonParser createParser(char[] content,
                                                          int offset,
                                                          int len)
                                                   throws IOException
        Factory method for constructing properly initialized JsonParser to read content from specified character array. Parser is not managed (or "owned") by ObjectMapper: caller is responsible for properly closing it once content reading is complete.
        Throws:
        IOException
        Since:
        2.11

      • createParser

        public com.fasterxml.jackson.core.JsonParser createParser(DataInput content)
                                                   throws IOException
        Factory method for constructing properly initialized JsonParser to read content using specified DataInput. Parser is not managed (or "owned") by ObjectMapper: caller is responsible for properly closing it once content reading is complete.
        Throws:
        IOException
        Since:
        2.11

      • createNonBlockingByteArrayParser

        public com.fasterxml.jackson.core.JsonParser createNonBlockingByteArrayParser()
                                                                       throws IOException
        Factory method for constructing properly initialized JsonParser to read content using non-blocking (asynchronous) mode. Parser is not managed (or "owned") by ObjectMapper: caller is responsible for properly closing it once content reading is complete.
        Throws:
        IOException
        Since:
        2.11

      • getSerializationConfig

        public SerializationConfig getSerializationConfig()
        Method that returns the shared default SerializationConfig object that defines configuration settings for serialization.

        Note that since instances are immutable, you can NOT change settings by accessing an instance and calling methods: this will simply create new instance of config object.

      • getDeserializationConfig

        public DeserializationConfig getDeserializationConfig()
        Method that returns the shared default DeserializationConfig object that defines configuration settings for deserialization.

        Note that since instances are immutable, you can NOT change settings by accessing an instance and calling methods: this will simply create new instance of config object.

      • getDeserializationContext

        public DeserializationContext getDeserializationContext()
        Method for getting current DeserializationContext.

        Note that since instances are immutable, you can NOT change settings by accessing an instance and calling methods: this will simply create new instance of context object.

      • getSerializerFactory

        public SerializerFactory getSerializerFactory()
        Method for getting current SerializerFactory.

        Note that since instances are immutable, you can NOT change settings by accessing an instance and calling methods: this will simply create new instance of factory object.

      • getSerializerProviderInstance

        public SerializerProvider getSerializerProviderInstance()
        Accessor for constructing and returning a SerializerProvider instance that may be used for accessing serializers. This is same as calling getSerializerProvider(), and calling createInstance on it.
        Since:
        2.7

      • setMixIns

        public ObjectMapper setMixIns(Map<Class<?>,Class<?>> sourceMixins)
        Method to use for defining mix-in annotations to use for augmenting annotations that processable (serializable / deserializable) classes have. Mixing in is done when introspecting class annotations and properties. Map passed contains keys that are target classes (ones to augment with new annotation overrides), and values that are source classes (have annotations to use for augmentation). Annotations from source classes (and their supertypes) will override annotations that target classes (and their super-types) have.

        Note that this method will CLEAR any previously defined mix-ins for this mapper.

        Since:
        2.5

      • addMixIn

        public ObjectMapper addMixIn(Class<?> target,
                             Class<?> mixinSource)
        Method to use for adding mix-in annotations to use for augmenting specified class or interface. All annotations from mixinSource are taken to override annotations that target (or its supertypes) has.
        Parameters:
        target - Class (or interface) whose annotations to effectively override
        mixinSource - Class (or interface) whose annotations are to be "added" to target's annotations, overriding as necessary
        Since:
        2.5

      • setMixInResolver

        public ObjectMapper setMixInResolver(ClassIntrospector.MixInResolver resolver)
        Method that can be called to specify given resolver for locating mix-in classes to use, overriding directly added mappings. Note that direct mappings are not cleared, but they are only applied if resolver does not provide mix-in matches.
        Since:
        2.6

      • findMixInClassFor

        public Class<?> findMixInClassFor(Class<?> cls)

      • mixInCount

        public int mixInCount()

      • getVisibilityChecker

        public VisibilityChecker<?> getVisibilityChecker()
        Method for accessing currently configured visibility checker; object used for determining whether given property element (method, field, constructor) can be auto-detected or not.

      • setVisibility

        public ObjectMapper setVisibility(VisibilityChecker<?> vc)
        Method for setting currently configured default VisibilityChecker, object used for determining whether given property element (method, field, constructor) can be auto-detected or not. This default checker is used as the base visibility: per-class overrides (both via annotations and per-type config overrides) can further change these settings.
        Since:
        2.6

      • setVisibility

        public ObjectMapper setVisibility(com.fasterxml.jackson.annotation.PropertyAccessor forMethod,
                                  com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility visibility)
        Convenience method that allows changing configuration for underlying VisibilityCheckers, to change details of what kinds of properties are auto-detected. Basically short cut for doing: 
          mapper.setVisibilityChecker(
     mapper.getVisibilityChecker().withVisibility(forMethod, visibility)
  );
        one common use case would be to do: 
          mapper.setVisibility(JsonMethod.FIELD, Visibility.ANY);
        which would make all member fields serializable without further annotations, instead of just public fields (default setting).
        Parameters:
        forMethod - Type of property descriptor affected (field, getter/isGetter, setter, creator)
        visibility - Minimum visibility to require for the property descriptors of type
        Returns:
        Modified mapper instance (that is, "this"), to allow chaining of configuration calls

      • getSubtypeResolver

        public SubtypeResolver getSubtypeResolver()
        Method for accessing subtype resolver in use.

      • setDefaultPrettyPrinter

        public ObjectMapper setDefaultPrettyPrinter(com.fasterxml.jackson.core.PrettyPrinter pp)
        Method for specifying PrettyPrinter to use when "default pretty-printing" is enabled (by enabling SerializationFeature.INDENT_OUTPUT)
        Parameters:
        pp - Pretty printer to use by default.
        Returns:
        This mapper, useful for call-chaining
        Since:
        2.6

      • setSerializationInclusion

        public ObjectMapper setSerializationInclusion(com.fasterxml.jackson.annotation.JsonInclude.Include incl)
        Convenience method, equivalent to calling: 
          setPropertyInclusion(JsonInclude.Value.construct(incl, incl));

        NOTE: behavior differs slightly from 2.8, where second argument was implied to be JsonInclude.Include.ALWAYS.

      • setDefaultPropertyInclusion

        public ObjectMapper setDefaultPropertyInclusion(com.fasterxml.jackson.annotation.JsonInclude.Value incl)
        Method for setting default POJO property inclusion strategy for serialization, applied for all properties for which there are no per-type or per-property overrides (via annotations or config overrides).
        Since:
        2.9 (basically rename of setPropertyInclusion)

      • setDefaultPropertyInclusion

        public ObjectMapper setDefaultPropertyInclusion(com.fasterxml.jackson.annotation.JsonInclude.Include incl)
        Short-cut for: 
          setDefaultPropertyInclusion(JsonInclude.Value.construct(incl, incl));
        Since:
        2.9 (basically rename of setPropertyInclusion)

      • setDefaultSetterInfo

        public ObjectMapper setDefaultSetterInfo(com.fasterxml.jackson.annotation.JsonSetter.Value v)
        Method for setting default Setter configuration, regarding things like merging, null-handling; used for properties for which there are no per-type or per-property overrides (via annotations or config overrides).
        Since:
        2.9

      • setDefaultVisibility

        public ObjectMapper setDefaultVisibility(com.fasterxml.jackson.annotation.JsonAutoDetect.Value vis)
        Method for setting auto-detection visibility definition defaults, which are in effect unless overridden by annotations (like JsonAutoDetect) or per-type visibility overrides.
        Since:
        2.9

      • setDefaultMergeable

        public ObjectMapper setDefaultMergeable(Boolean b)
        Method for setting default Setter configuration, regarding things like merging, null-handling; used for properties for which there are no per-type or per-property overrides (via annotations or config overrides).
        Since:
        2.9

      • registerSubtypes

        public void registerSubtypes(Class<?>... classes)
        Method for registering specified class as a subtype, so that typename-based resolution can link supertypes to subtypes (as an alternative to using annotations). Type for given class is determined from appropriate annotation; or if missing, default name (unqualified class name)

      • registerSubtypes

        public void registerSubtypes(NamedType... types)
        Method for registering specified class as a subtype, so that typename-based resolution can link supertypes to subtypes (as an alternative to using annotations). Name may be provided as part of argument, but if not will be based on annotations or use default name (unqualified class name).

      • registerSubtypes

        public void registerSubtypes(Collection<Class<?>> subtypes)
        Since:
        2.9

      • activateDefaultTyping

        public ObjectMapper activateDefaultTyping(PolymorphicTypeValidator ptv)
        Convenience method that is equivalent to calling 
          activateDefaultTyping(ptv, DefaultTyping.OBJECT_AND_NON_CONCRETE);

        NOTE: choice of PolymorphicTypeValidator to pass is critical for security as allowing all subtypes can be risky for untrusted content.

        Parameters:
        ptv - Validator used to verify that actual subtypes to deserialize are valid against whatever criteria validator uses: important in case where untrusted content is deserialized.
        Since:
        2.10

      • activateDefaultTyping

        public ObjectMapper activateDefaultTyping(PolymorphicTypeValidator ptv,
                                          ObjectMapper.DefaultTyping applicability)
        Convenience method that is equivalent to calling 
          activateDefaultTyping(ptv, dti, JsonTypeInfo.As.WRAPPER_ARRAY);

        NOTE: choice of PolymorphicTypeValidator to pass is critical for security as allowing all subtypes can be risky for untrusted content.

        Parameters:
        ptv - Validator used to verify that actual subtypes to deserialize are valid against whatever criteria validator uses: important in case where untrusted content is deserialized.
        applicability - Defines kinds of types for which additional type information is added; see ObjectMapper.DefaultTyping for more information.
        Since:
        2.10

      • activateDefaultTyping

        public ObjectMapper activateDefaultTyping(PolymorphicTypeValidator ptv,
                                          ObjectMapper.DefaultTyping applicability,
                                          com.fasterxml.jackson.annotation.JsonTypeInfo.As includeAs)
        Method for enabling automatic inclusion of type information ("Default Typing"), needed for proper deserialization of polymorphic types (unless types have been annotated with JsonTypeInfo).

        NOTE: use of JsonTypeInfo.As#EXTERNAL_PROPERTY NOT SUPPORTED; and attempts of do so will throw an IllegalArgumentException to make this limitation explicit.

        NOTE: choice of PolymorphicTypeValidator to pass is critical for security as allowing all subtypes can be risky for untrusted content.

        Parameters:
        ptv - Validator used to verify that actual subtypes to deserialize are valid against whatever criteria validator uses: important in case where untrusted content is deserialized.
        applicability - Defines kinds of types for which additional type information is added; see ObjectMapper.DefaultTyping for more information.
        includeAs -
        Since:
        2.10

      • activateDefaultTypingAsProperty

        public ObjectMapper activateDefaultTypingAsProperty(PolymorphicTypeValidator ptv,
                                                    ObjectMapper.DefaultTyping applicability,
                                                    String propertyName)
        Method for enabling automatic inclusion of type information ("Default Typing") -- needed for proper deserialization of polymorphic types (unless types have been annotated with JsonTypeInfo) -- using "As.PROPERTY" inclusion mechanism and specified property name to use for inclusion (default being "@class" since default type information always uses class name as type identifier)

        NOTE: choice of PolymorphicTypeValidator to pass is critical for security as allowing all subtypes can be risky for untrusted content.

        Parameters:
        ptv - Validator used to verify that actual subtypes to deserialize are valid against whatever criteria validator uses: important in case where untrusted content is deserialized.
        applicability - Defines kinds of types for which additional type information is added; see ObjectMapper.DefaultTyping for more information.
        propertyName - Name of property used for including type id for polymorphic values.
        Since:
        2.10

      • deactivateDefaultTyping

        public ObjectMapper deactivateDefaultTyping()
        Method for disabling automatic inclusion of type information; if so, only explicitly annotated types (ones with JsonTypeInfo) will have additional embedded type information.
        Since:
        2.10

      • setDefaultTyping

        public ObjectMapper setDefaultTyping(TypeResolverBuilder<?> typer)
        Method for enabling automatic inclusion of type information ("Default Typing"), using specified handler object for determining which types this affects, as well as details of how information is embedded.

        NOTE: use of Default Typing can be a potential security risk if incoming content comes from untrusted sources, so care should be taken to use a TypeResolverBuilder that can limit allowed classes to deserialize. Note in particular that StdTypeResolverBuilder DOES NOT limit applicability but creates type (de)serializers for all types.

        Parameters:
        typer - Type information inclusion handler

      • configOverride

        public MutableConfigOverride configOverride(Class<?> type)
        Accessor for getting a mutable configuration override object for given type, needed to add or change per-type overrides applied to properties of given type. Usage is through returned object by calling "setter" methods, which directly modify override object and take effect directly. For example you can do 
           mapper.configOverride(java.util.Date.class)
       .setFormat(JsonFormat.Value.forPattern("yyyy-MM-dd"));
        to change the default format to use for properties of type Date (possibly further overridden by per-property annotations)
        Since:
        2.8

      • coercionConfigDefaults

        public MutableCoercionConfig coercionConfigDefaults()
        Accessor for MutableCoercionConfig through which default (fallback) coercion configurations can be changed. Note that such settings are only applied if more specific (by logical and physical type) configuration have not been defined.
        Since:
        2.12

      • getTypeFactory

        public TypeFactory getTypeFactory()
        Accessor for getting currently configured TypeFactory instance.

      • setTypeFactory

        public ObjectMapper setTypeFactory(TypeFactory f)
        Method that can be used to override TypeFactory instance used by this mapper.

        Note: will also set TypeFactory that deserialization and serialization config objects use.

      • constructType

        public JavaType constructType(Type t)
        Convenience method for constructing JavaType out of given type (typically java.lang.Class), but without explicit context.

      • getNodeFactory

        public JsonNodeFactory getNodeFactory()
        Method that can be used to get hold of JsonNodeFactory that this mapper will use when directly constructing root JsonNode instances for Trees.

        Note: this is just a shortcut for calling 

           getDeserializationConfig().getNodeFactory()

      • setConstructorDetector

        public ObjectMapper setConstructorDetector(ConstructorDetector cd)
        Method for specifying ConstructorDetector to use for determining some aspects of creator auto-detection (specifically auto-detection of constructor, and in particular behavior with single-argument constructors).
        Since:
        2.12

      • setConfig

        public ObjectMapper setConfig(DeserializationConfig config)
        Method that allows overriding of the underlying DeserializationConfig object. It is added as a fallback method that may be used if no other configuration modifier method works: it should not be used if there are alternatives, and its use is generally discouraged.

        NOTE: only use this method if you know what you are doing -- it allows by-passing some of checks applied to other configuration methods. Also keep in mind that as with all configuration of ObjectMapper, this is only thread-safe if done before calling any deserialization methods.

        Since:
        2.4

      • setFilterProvider

        public ObjectMapper setFilterProvider(FilterProvider filterProvider)
        Method for configuring this mapper to use specified FilterProvider for mapping Filter Ids to actual filter instances.

        Note that usually it is better to use method writer(FilterProvider); however, sometimes this method is more convenient. For example, some frameworks only allow configuring of ObjectMapper instances and not ObjectWriters.

        Since:
        2.6

      • setBase64Variant

        public ObjectMapper setBase64Variant(com.fasterxml.jackson.core.Base64Variant v)
        Method that will configure default Base64Variant that byte[] serializers and deserializers will use.
        Parameters:
        v - Base64 variant to use
        Returns:
        This mapper, for convenience to allow chaining
        Since:
        2.1

      • setConfig

        public ObjectMapper setConfig(SerializationConfig config)
        Method that allows overriding of the underlying SerializationConfig object, which contains serialization-specific configuration settings. It is added as a fallback method that may be used if no other configuration modifier method works: it should not be used if there are alternatives, and its use is generally discouraged.

        NOTE: only use this method if you know what you are doing -- it allows by-passing some of checks applied to other configuration methods. Also keep in mind that as with all configuration of ObjectMapper, this is only thread-safe if done before calling any serialization methods.

        Since:
        2.4

      • tokenStreamFactory

        public com.fasterxml.jackson.core.JsonFactory tokenStreamFactory()
        Method that can be used to get hold of JsonFactory that this mapper uses if it needs to construct JsonParsers and/or JsonGenerators.

        WARNING: note that all ObjectReader and ObjectWriter instances created by this mapper usually share the same configured JsonFactory, so changes to its configuration will "leak". To avoid such observed changes you should always use "with()" and "without()" method of ObjectReader and ObjectWriter for changing JsonParser.Feature and JsonGenerator.Feature settings to use on per-call basis.

        Returns:
        JsonFactory that this mapper uses when it needs to construct Json parser and generators
        Since:
        2.10

      • getFactory

        public com.fasterxml.jackson.core.JsonFactory getFactory()
        Overrides:
        getFactory in class com.fasterxml.jackson.core.ObjectCodec

      • getJsonFactory

        @Deprecated
public com.fasterxml.jackson.core.JsonFactory getJsonFactory()
        Deprecated. Since 2.1: Use getFactory() instead
        Overrides:
        getJsonFactory in class com.fasterxml.jackson.core.ObjectCodec

      • setDateFormat

        public ObjectMapper setDateFormat(DateFormat dateFormat)
        Method for configuring the default DateFormat to use when serializing time values as Strings, and deserializing from JSON Strings. This is preferably to directly modifying SerializationConfig and DeserializationConfig instances. If you need per-request configuration, use writer(DateFormat) to create properly configured ObjectWriter and use that; this because ObjectWriters are thread-safe whereas ObjectMapper itself is only thread-safe when configuring methods (such as this one) are NOT called.

      • getDateFormat

        public DateFormat getDateFormat()
        Since:
        2.5

      • setHandlerInstantiator

        public Object setHandlerInstantiator(HandlerInstantiator hi)
        Method for configuring HandlerInstantiator to use for creating instances of handlers (such as serializers, deserializers, type and type id resolvers), given a class.
        Parameters:
        hi - Instantiator to use; if null, use the default implementation

      • getInjectableValues

        public InjectableValues getInjectableValues()
        Since:
        2.6

      • setTimeZone

        public ObjectMapper setTimeZone(TimeZone tz)
        Method for overriding default TimeZone to use for formatting. Default value used is UTC (NOT default TimeZone of JVM).

      • isEnabled

        public boolean isEnabled(SerializationFeature f)
        Method for checking whether given serialization-specific feature is enabled.

      • configure

        public ObjectMapper configure(SerializationFeature f,
                              boolean state)
        Method for changing state of an on/off serialization feature for this object mapper.

      • isEnabled

        public boolean isEnabled(DeserializationFeature f)
        Method for checking whether given deserialization-specific feature is enabled.

      • configure

        public ObjectMapper configure(DeserializationFeature f,
                              boolean state)
        Method for changing state of an on/off deserialization feature for this object mapper.

      • isEnabled

        public boolean isEnabled(com.fasterxml.jackson.core.JsonParser.Feature f)

      • configure

        public ObjectMapper configure(com.fasterxml.jackson.core.JsonParser.Feature f,
                              boolean state)
        Method for changing state of specified JsonParser.Features for parser instances this object mapper creates.

        Note that this is equivalent to directly calling same method on getFactory().

        WARNING: since this method directly modifies state of underlying JsonFactory, it will change observed configuration by ObjectReaders as well -- to avoid this, use ObjectReader.with(JsonParser.Feature) instead.

      • enable

        public ObjectMapper enable(com.fasterxml.jackson.core.JsonParser.Feature... features)
        Method for enabling specified JsonParser.Features for parser instances this object mapper creates.

        Note that this is equivalent to directly calling same method on getFactory().

        WARNING: since this method directly modifies state of underlying JsonFactory, it will change observed configuration by ObjectReaders as well -- to avoid this, use ObjectReader.with(JsonParser.Feature) instead.

        Since:
        2.5

      • disable

        public ObjectMapper disable(com.fasterxml.jackson.core.JsonParser.Feature... features)
        Method for disabling specified JsonParser.Features for parser instances this object mapper creates.

        Note that this is equivalent to directly calling same method on getFactory().

        WARNING: since this method directly modifies state of underlying JsonFactory, it will change observed configuration by ObjectReaders as well -- to avoid this, use ObjectReader.without(JsonParser.Feature) instead.

        Since:
        2.5

      • isEnabled

        public boolean isEnabled(com.fasterxml.jackson.core.JsonGenerator.Feature f)

      • configure

        public ObjectMapper configure(com.fasterxml.jackson.core.JsonGenerator.Feature f,
                              boolean state)
        Method for changing state of an on/off JsonGenerator feature for generator instances this object mapper creates.

        Note that this is equivalent to directly calling same method on getFactory().

        WARNING: since this method directly modifies state of underlying JsonFactory, it will change observed configuration by ObjectWriters as well -- to avoid this, use ObjectWriter.with(JsonGenerator.Feature) instead.

      • enable

        public ObjectMapper enable(com.fasterxml.jackson.core.JsonGenerator.Feature... features)
        Method for enabling specified JsonGenerator.Features for parser instances this object mapper creates.

        Note that this is equivalent to directly calling same method on getFactory().

        WARNING: since this method directly modifies state of underlying JsonFactory, it will change observed configuration by ObjectWriters as well -- to avoid this, use ObjectWriter.with(JsonGenerator.Feature) instead.

        Since:
        2.5

      • disable

        public ObjectMapper disable(com.fasterxml.jackson.core.JsonGenerator.Feature... features)
        Method for disabling specified JsonGenerator.Features for parser instances this object mapper creates.

        Note that this is equivalent to directly calling same method on getFactory().

        WARNING: since this method directly modifies state of underlying JsonFactory, it will change observed configuration by ObjectWriters as well -- to avoid this, use ObjectWriter.without(JsonGenerator.Feature) instead.

        Since:
        2.5

      • isEnabled

        public boolean isEnabled(com.fasterxml.jackson.core.JsonFactory.Feature f)
        Convenience method, equivalent to: 
          getJsonFactory().isEnabled(f);

      • isEnabled

        public boolean isEnabled(com.fasterxml.jackson.core.StreamReadFeature f)
        Since:
        2.10

      • isEnabled

        public boolean isEnabled(com.fasterxml.jackson.core.StreamWriteFeature f)
        Since:
        2.10

      • readValue

        public <T> T readValue(com.fasterxml.jackson.core.JsonParser p,
                       Class<T> valueType)
                throws IOException,
                       com.fasterxml.jackson.core.JsonParseException,
                       JsonMappingException
        Method to deserialize JSON content into a non-container type (it can be an array type, however): typically a bean, array or a wrapper type (like Boolean).

        Note: this method should NOT be used if the result type is a container (Collection or Map. The reason is that due to type erasure, key and value types cannot be introspected when using this method.

        Specified by:
        readValue in class com.fasterxml.jackson.core.ObjectCodec
        Throws:
        IOException - if a low-level I/O problem (unexpected end-of-input, network error) occurs (passed through as-is without additional wrapping -- note that this is one case where DeserializationFeature.WRAP_EXCEPTIONS does NOT result in wrapping of exception even if enabled)
        com.fasterxml.jackson.core.JsonParseException - if underlying input contains invalid content of type JsonParser supports (JSON for default case)
        JsonMappingException - if the input JSON structure does not match structure expected for result type (or has other mismatch issues)

      • readValue

        public <T> T readValue(com.fasterxml.jackson.core.JsonParser p,
                       com.fasterxml.jackson.core.type.TypeReference<T> valueTypeRef)
                throws IOException,
                       com.fasterxml.jackson.core.JsonParseException,
                       JsonMappingException
        Method to deserialize JSON content into a Java type, reference to which is passed as argument. Type is passed using so-called "super type token" (see ) and specifically needs to be used if the root type is a parameterized (generic) container type.
        Specified by:
        readValue in class com.fasterxml.jackson.core.ObjectCodec
        Throws:
        IOException - if a low-level I/O problem (unexpected end-of-input, network error) occurs (passed through as-is without additional wrapping -- note that this is one case where DeserializationFeature.WRAP_EXCEPTIONS does NOT result in wrapping of exception even if enabled)
        com.fasterxml.jackson.core.JsonParseException - if underlying input contains invalid content of type JsonParser supports (JSON for default case)
        JsonMappingException - if the input JSON structure does not match structure expected for result type (or has other mismatch issues)

      • readValue

        public final <T> T readValue(com.fasterxml.jackson.core.JsonParser p,
                             com.fasterxml.jackson.core.type.ResolvedType valueType)
                      throws IOException,
                             com.fasterxml.jackson.core.JsonParseException,
                             JsonMappingException
        Method to deserialize JSON content into a Java type, reference to which is passed as argument. Type is passed using Jackson specific type; instance of which can be constructed using TypeFactory.
        Specified by:
        readValue in class com.fasterxml.jackson.core.ObjectCodec
        Throws:
        IOException - if a low-level I/O problem (unexpected end-of-input, network error) occurs (passed through as-is without additional wrapping -- note that this is one case where DeserializationFeature.WRAP_EXCEPTIONS does NOT result in wrapping of exception even if enabled)
        com.fasterxml.jackson.core.JsonParseException - if underlying input contains invalid content of type JsonParser supports (JSON for default case)
        JsonMappingException - if the input JSON structure does not match structure expected for result type (or has other mismatch issues)

      • readValue

        public <T> T readValue(com.fasterxml.jackson.core.JsonParser p,
                       JavaType valueType)
                throws IOException,
                       com.fasterxml.jackson.core.JsonParseException,
                       JsonMappingException
        Type-safe overloaded method, basically alias for readValue(JsonParser, Class).
        Throws:
        IOException - if a low-level I/O problem (unexpected end-of-input, network error) occurs (passed through as-is without additional wrapping -- note that this is one case where DeserializationFeature.WRAP_EXCEPTIONS does NOT result in wrapping of exception even if enabled)
        com.fasterxml.jackson.core.JsonParseException - if underlying input contains invalid content of type JsonParser supports (JSON for default case)
        JsonMappingException - if the input JSON structure does not match structure expected for result type (or has other mismatch issues)

      • readTree

        public <T extends com.fasterxml.jackson.core.TreeNode> T readTree(com.fasterxml.jackson.core.JsonParser p)
                                                           throws IOException,
                                                                  com.fasterxml.jackson.core.JsonProcessingException
        Method to deserialize JSON content as a tree JsonNode. Returns JsonNode that represents the root of the resulting tree, if there was content to read, or null if no more content is accessible via passed JsonParser.

        NOTE! Behavior with end-of-input (no more content) differs between this readTree method, and all other methods that take input source: latter will return "missing node", NOT null

        Specified by:
        readTree in class com.fasterxml.jackson.core.ObjectCodec
        Returns:
        a JsonNode, if valid JSON content found; null if input has no content to bind -- note, however, that if JSON null token is found, it will be represented as a non-null JsonNode (one that returns true for JsonNode.isNull()
        Throws:
        IOException - if a low-level I/O problem (unexpected end-of-input, network error) occurs (passed through as-is without additional wrapping -- note that this is one case where DeserializationFeature.WRAP_EXCEPTIONS does NOT result in wrapping of exception even if enabled)
        com.fasterxml.jackson.core.JsonParseException - if underlying input contains invalid content of type JsonParser supports (JSON for default case)
        com.fasterxml.jackson.core.JsonProcessingException

      • readValues

        public <T> MappingIterator<T> readValues(com.fasterxml.jackson.core.JsonParser p,
                                         com.fasterxml.jackson.core.type.ResolvedType valueType)
                                  throws IOException,
                                         com.fasterxml.jackson.core.JsonProcessingException
        Convenience method, equivalent in function to: 
           readerFor(valueType).readValues(p);

        Method for reading sequence of Objects from parser stream. Sequence can be either root-level "unwrapped" sequence (without surrounding JSON array), or a sequence contained in a JSON Array. In either case JsonParser MUST point to the first token of the first element, OR not point to any token (in which case it is advanced to the next token). This means, specifically, that for wrapped sequences, parser MUST NOT point to the surrounding START_ARRAY (one that contains values to read) but rather to the token following it which is the first token of the first value to read.

        Note that ObjectReader has more complete set of variants.

        Specified by:
        readValues in class com.fasterxml.jackson.core.ObjectCodec
        Throws:
        IOException
        com.fasterxml.jackson.core.JsonProcessingException

      • readValues

        public <T> MappingIterator<T> readValues(com.fasterxml.jackson.core.JsonParser p,
                                         Class<T> valueType)
                                  throws IOException,
                                         com.fasterxml.jackson.core.JsonProcessingException
        Convenience method, equivalent in function to: 
           readerFor(valueType).readValues(p);

        Type-safe overload of readValues(JsonParser, ResolvedType).

        Specified by:
        readValues in class com.fasterxml.jackson.core.ObjectCodec
        Throws:
        IOException
        com.fasterxml.jackson.core.JsonProcessingException

      • readValues

        public <T> MappingIterator<T> readValues(com.fasterxml.jackson.core.JsonParser p,
                                         com.fasterxml.jackson.core.type.TypeReference<T> valueTypeRef)
                                  throws IOException,
                                         com.fasterxml.jackson.core.JsonProcessingException
        Method for reading sequence of Objects from parser stream.
        Specified by:
        readValues in class com.fasterxml.jackson.core.ObjectCodec
        Throws:
        IOException
        com.fasterxml.jackson.core.JsonProcessingException

      • readTree

        public JsonNode readTree(InputStream in)
                  throws IOException
        Method to deserialize JSON content as tree expressed using set of JsonNode instances. Returns root of the resulting tree (where root can consist of just a single node if the current event is a value event, not container).

        If a low-level I/O problem (missing input, network error) occurs, a IOException will be thrown. If a parsing problem occurs (invalid JSON), JsonParseException will be thrown. If no content is found from input (end-of-input), Java null will be returned.

        Parameters:
        in - Input stream used to read JSON content for building the JSON tree.
        Returns:
        a JsonNode, if valid JSON content found; null if input has no content to bind -- note, however, that if JSON null token is found, it will be represented as a non-null JsonNode (one that returns true for JsonNode.isNull()
        Throws:
        com.fasterxml.jackson.core.JsonParseException - if underlying input contains invalid content of type JsonParser supports (JSON for default case)
        IOException

      • writeValue

        public void writeValue(com.fasterxml.jackson.core.JsonGenerator g,
                       Object value)
                throws IOException,
                       com.fasterxml.jackson.core.JsonGenerationException,
                       JsonMappingException
        Method that can be used to serialize any Java value as JSON output, using provided JsonGenerator.
        Specified by:
        writeValue in class com.fasterxml.jackson.core.ObjectCodec
        Throws:
        IOException
        com.fasterxml.jackson.core.JsonGenerationException
        JsonMappingException

      • writeTree

        public void writeTree(com.fasterxml.jackson.core.JsonGenerator g,
                      com.fasterxml.jackson.core.TreeNode rootNode)
               throws IOException,
                      com.fasterxml.jackson.core.JsonProcessingException
        Specified by:
        writeTree in class com.fasterxml.jackson.core.ObjectCodec
        Throws:
        IOException
        com.fasterxml.jackson.core.JsonProcessingException

      • writeTree

        public void writeTree(com.fasterxml.jackson.core.JsonGenerator g,
                      JsonNode rootNode)
               throws IOException,
                      com.fasterxml.jackson.core.JsonProcessingException
        Method to serialize given JSON Tree, using generator provided.
        Throws:
        IOException
        com.fasterxml.jackson.core.JsonProcessingException

      • createObjectNode

        public ObjectNode createObjectNode()

        Note: return type is co-variant, as basic ObjectCodec abstraction cannot refer to concrete node types (as it's part of core package, whereas impls are part of mapper package)

        Specified by:
        createObjectNode in class com.fasterxml.jackson.core.ObjectCodec

      • createArrayNode

        public ArrayNode createArrayNode()

        Note: return type is co-variant, as basic ObjectCodec abstraction cannot refer to concrete node types (as it's part of core package, whereas impls are part of mapper package)

        Specified by:
        createArrayNode in class com.fasterxml.jackson.core.ObjectCodec

      • missingNode

        public JsonNode missingNode()
        Overrides:
        missingNode in class com.fasterxml.jackson.core.TreeCodec

      • nullNode

        public JsonNode nullNode()
        Overrides:
        nullNode in class com.fasterxml.jackson.core.TreeCodec

      • treeAsTokens

        public com.fasterxml.jackson.core.JsonParser treeAsTokens(com.fasterxml.jackson.core.TreeNode n)
        Method for constructing a JsonParser out of JSON tree representation.
        Specified by:
        treeAsTokens in class com.fasterxml.jackson.core.ObjectCodec
        Parameters:
        n - Root node of the tree that resulting parser will read from

      • treeToValue

        public <T> T treeToValue(com.fasterxml.jackson.core.TreeNode n,
                         Class<T> valueType)
                  throws IllegalArgumentException
        Convenience conversion method that will bind data given JSON tree contains into specific value (usually bean) type.

        Functionally equivalent to: 

           objectMapper.convertValue(n, valueClass);

        Specified by:
        treeToValue in class com.fasterxml.jackson.core.ObjectCodec
        Throws:
        IllegalArgumentException

      • valueToTree

        public <T extends JsonNode> T valueToTree(Object fromValue)
                                   throws IllegalArgumentException
        Reverse of treeToValue(com.fasterxml.jackson.core.TreeNode, java.lang.Class<T>); given a value (usually bean), will construct equivalent JSON Tree representation. Functionally similar to serializing value into JSON and parsing JSON as tree, but more efficient.

        NOTE: while results are usually identical to that of serialization followed by deserialization, this is not always the case. In some cases serialization into intermediate representation will retain encapsulation of things like raw value (RawValue) or basic node identity (JsonNode). If so, result is a valid tree, but values are not re-constructed through actual JSON representation. So if transformation requires actual materialization of JSON (or other data format that this mapper produces), it will be necessary to do actual serialization.

        Type Parameters:
        T - Actual node type; usually either basic JsonNode or ObjectNode
        Parameters:
        fromValue - Bean value to convert
        Returns:
        (non-null) Root node of the resulting JSON tree: in case of null value, node for which JsonNode.isNull() returns true.
        Throws:
        IllegalArgumentException

      • canSerialize

        public boolean canSerialize(Class<?> type)
        Method that can be called to check whether mapper thinks it could serialize an instance of given Class. Check is done by checking whether a serializer can be found for the type.

        NOTE: since this method does NOT throw exceptions, but internal processing may, caller usually has little information as to why serialization would fail. If you want access to internal Exception, call canSerialize(Class, AtomicReference) instead.

        Returns:
        True if mapper can find a serializer for instances of given class (potentially serializable), false otherwise (not serializable)

      • canSerialize

        public boolean canSerialize(Class<?> type,
                            AtomicReference<Throwable> cause)
        Method similar to canSerialize(Class) but that can return actual Throwable that was thrown when trying to construct serializer: this may be useful in figuring out what the actual problem is.
        Since:
        2.3

      • canDeserialize

        public boolean canDeserialize(JavaType type)
        Method that can be called to check whether mapper thinks it could deserialize an Object of given type. Check is done by checking whether a registered deserializer can be found or built for the type; if not (either by no mapping being found, or through an Exception being thrown, false is returned.

        NOTE: in case an exception is thrown during course of trying co construct matching deserializer, it will be effectively swallowed. If you want access to that exception, call canDeserialize(JavaType, AtomicReference) instead.

        Returns:
        True if mapper can find a serializer for instances of given class (potentially serializable), false otherwise (not serializable)

      • readValue

        public <T> T readValue(File src,
                       Class<T> valueType)
                throws IOException,
                       com.fasterxml.jackson.core.JsonParseException,
                       JsonMappingException
        Method to deserialize JSON content from given file into given Java type.
        Throws:
        IOException - if a low-level I/O problem (unexpected end-of-input, network error) occurs (passed through as-is without additional wrapping -- note that this is one case where DeserializationFeature.WRAP_EXCEPTIONS does NOT result in wrapping of exception even if enabled)
        com.fasterxml.jackson.core.JsonParseException - if underlying input contains invalid content of type JsonParser supports (JSON for default case)
        JsonMappingException - if the input JSON structure does not match structure expected for result type (or has other mismatch issues)

      • readValue

        public <T> T readValue(File src,
                       com.fasterxml.jackson.core.type.TypeReference<T> valueTypeRef)
                throws IOException,
                       com.fasterxml.jackson.core.JsonParseException,
                       JsonMappingException
        Method to deserialize JSON content from given file into given Java type.
        Throws:
        IOException - if a low-level I/O problem (unexpected end-of-input, network error) occurs (passed through as-is without additional wrapping -- note that this is one case where DeserializationFeature.WRAP_EXCEPTIONS does NOT result in wrapping of exception even if enabled)
        com.fasterxml.jackson.core.JsonParseException - if underlying input contains invalid content of type JsonParser supports (JSON for default case)
        JsonMappingException - if the input JSON structure does not match structure expected for result type (or has other mismatch issues)

      • readValue

        public <T> T readValue(File src,
                       JavaType valueType)
                throws IOException,
                       com.fasterxml.jackson.core.JsonParseException,
                       JsonMappingException
        Method to deserialize JSON content from given file into given Java type.
        Throws:
        IOException - if a low-level I/O problem (unexpected end-of-input, network error) occurs (passed through as-is without additional wrapping -- note that this is one case where DeserializationFeature.WRAP_EXCEPTIONS does NOT result in wrapping of exception even if enabled)
        com.fasterxml.jackson.core.JsonParseException - if underlying input contains invalid content of type JsonParser supports (JSON for default case)
        JsonMappingException - if the input JSON structure does not match structure expected for result type (or has other mismatch issues)

      • readValue

        public <T> T readValue(URL src,
                       Class<T> valueType)
                throws IOException,
                       com.fasterxml.jackson.core.JsonParseException,
                       JsonMappingException
        Method to deserialize JSON content from given resource into given Java type.

        NOTE: handling of URL is delegated to JsonFactory.createParser(java.net.URL) and usually simply calls URL.openStream(), meaning no special handling is done. If different HTTP connection options are needed you will need to create InputStream separately.

        Throws:
        IOException - if a low-level I/O problem (unexpected end-of-input, network error) occurs (passed through as-is without additional wrapping -- note that this is one case where DeserializationFeature.WRAP_EXCEPTIONS does NOT result in wrapping of exception even if enabled)
        com.fasterxml.jackson.core.JsonParseException - if underlying input contains invalid content of type JsonParser supports (JSON for default case)
        JsonMappingException - if the input JSON structure does not match structure expected for result type (or has other mismatch issues)

      • readValue

        public <T> T readValue(String content,
                       Class<T> valueType)
                throws com.fasterxml.jackson.core.JsonProcessingException,
                       JsonMappingException
        Method to deserialize JSON content from given JSON content String.
        Throws:
        com.fasterxml.jackson.core.JsonParseException - if underlying input contains invalid content of type JsonParser supports (JSON for default case)
        JsonMappingException - if the input JSON structure does not match structure expected for result type (or has other mismatch issues)
        com.fasterxml.jackson.core.JsonProcessingException

      • readValue

        public <T> T readValue(String content,
                       com.fasterxml.jackson.core.type.TypeReference<T> valueTypeRef)
                throws com.fasterxml.jackson.core.JsonProcessingException,
                       JsonMappingException
        Method to deserialize JSON content from given JSON content String.
        Throws:
        com.fasterxml.jackson.core.JsonParseException - if underlying input contains invalid content of type JsonParser supports (JSON for default case)
        JsonMappingException - if the input JSON structure does not match structure expected for result type (or has other mismatch issues)
        com.fasterxml.jackson.core.JsonProcessingException

      • readValue

        public <T> T readValue(String content,
                       JavaType valueType)
                throws com.fasterxml.jackson.core.JsonProcessingException,
                       JsonMappingException
        Method to deserialize JSON content from given JSON content String.
        Throws:
        com.fasterxml.jackson.core.JsonParseException - if underlying input contains invalid content of type JsonParser supports (JSON for default case)
        JsonMappingException - if the input JSON structure does not match structure expected for result type (or has other mismatch issues)
        com.fasterxml.jackson.core.JsonProcessingException

      • readValue

        public <T> T readValue(byte[] src,
                       int offset,
                       int len,
                       com.fasterxml.jackson.core.type.TypeReference<T> valueTypeRef)
                throws IOException,
                       com.fasterxml.jackson.core.JsonParseException,
                       JsonMappingException
        Throws:
        IOException
        com.fasterxml.jackson.core.JsonParseException
        JsonMappingException

      • writeValue

        public void writeValue(OutputStream out,
                       Object value)
                throws IOException,
                       com.fasterxml.jackson.core.JsonGenerationException,
                       JsonMappingException
        Method that can be used to serialize any Java value as JSON output, using output stream provided (using encoding JsonEncoding.UTF8).

        Note: method does not close the underlying stream explicitly here; however, JsonFactory this mapper uses may choose to close the stream depending on its settings (by default, it will try to close it when JsonGenerator we construct is closed).

        Throws:
        IOException
        com.fasterxml.jackson.core.JsonGenerationException
        JsonMappingException

      • writeValue

        public void writeValue(Writer w,
                       Object value)
                throws IOException,
                       com.fasterxml.jackson.core.JsonGenerationException,
                       JsonMappingException
        Method that can be used to serialize any Java value as JSON output, using Writer provided.

        Note: method does not close the underlying stream explicitly here; however, JsonFactory this mapper uses may choose to close the stream depending on its settings (by default, it will try to close it when JsonGenerator we construct is closed).

        Throws:
        IOException
        com.fasterxml.jackson.core.JsonGenerationException
        JsonMappingException

      • writeValueAsString

        public String writeValueAsString(Object value)
                          throws com.fasterxml.jackson.core.JsonProcessingException
        Method that can be used to serialize any Java value as a String. Functionally equivalent to calling writeValue(Writer,Object) with StringWriter and constructing String, but more efficient.

        Note: prior to version 2.1, throws clause included IOException; 2.1 removed it.

        Throws:
        com.fasterxml.jackson.core.JsonProcessingException

      • writeValueAsBytes

        public byte[] writeValueAsBytes(Object value)
                         throws com.fasterxml.jackson.core.JsonProcessingException
        Method that can be used to serialize any Java value as a byte array. Functionally equivalent to calling writeValue(Writer,Object) with ByteArrayOutputStream and getting bytes, but more efficient. Encoding used will be UTF-8.

        Note: prior to version 2.1, throws clause included IOException; 2.1 removed it.

        Throws:
        com.fasterxml.jackson.core.JsonProcessingException

      • writerWithView

        public ObjectWriter writerWithView(Class<?> serializationView)
        Factory method for constructing ObjectWriter that will serialize objects using specified JSON View (filter).

      • writerFor

        public ObjectWriter writerFor(Class<?> rootType)
        Factory method for constructing ObjectWriter that will serialize objects using specified root type, instead of actual runtime type of value. Type must be a super-type of runtime type.

        Main reason for using this method is performance, as writer is able to pre-fetch serializer to use before write, and if writer is used more than once this avoids addition per-value serializer lookups.

        Since:
        2.5

      • writerFor

        public ObjectWriter writerFor(com.fasterxml.jackson.core.type.TypeReference<?> rootType)
        Factory method for constructing ObjectWriter that will serialize objects using specified root type, instead of actual runtime type of value. Type must be a super-type of runtime type.

        Main reason for using this method is performance, as writer is able to pre-fetch serializer to use before write, and if writer is used more than once this avoids addition per-value serializer lookups.

        Since:
        2.5

      • writerFor

        public ObjectWriter writerFor(JavaType rootType)
        Factory method for constructing ObjectWriter that will serialize objects using specified root type, instead of actual runtime type of value. Type must be a super-type of runtime type.

        Main reason for using this method is performance, as writer is able to pre-fetch serializer to use before write, and if writer is used more than once this avoids addition per-value serializer lookups.

        Since:
        2.5

      • writer

        public ObjectWriter writer(com.fasterxml.jackson.core.PrettyPrinter pp)
        Factory method for constructing ObjectWriter that will serialize objects using specified pretty printer for indentation (or if null, no pretty printer)

      • writerWithDefaultPrettyPrinter

        public ObjectWriter writerWithDefaultPrettyPrinter()
        Factory method for constructing ObjectWriter that will serialize objects using the default pretty printer for indentation

      • writer

        public ObjectWriter writer(com.fasterxml.jackson.core.FormatSchema schema)
        Factory method for constructing ObjectWriter that will pass specific schema object to JsonGenerator used for writing content.
        Parameters:
        schema - Schema to pass to generator

      • writer

        public ObjectWriter writer(com.fasterxml.jackson.core.Base64Variant defaultBase64)
        Factory method for constructing ObjectWriter that will use specified Base64 encoding variant for Base64-encoded binary data.
        Since:
        2.1

      • writer

        public ObjectWriter writer(com.fasterxml.jackson.core.io.CharacterEscapes escapes)
        Factory method for constructing ObjectReader that will use specified character escaping details for output.
        Since:
        2.3

      • reader

        public ObjectReader reader()
        Factory method for constructing ObjectReader with default settings. Note that the resulting instance is NOT usable as is, without defining expected value type.

      • reader

        public ObjectReader reader(DeserializationFeature feature)
        Factory method for constructing ObjectReader with specified feature enabled (compared to settings that this mapper instance has). Note that the resulting instance is NOT usable as is, without defining expected value type.

      • readerForUpdating

        public ObjectReader readerForUpdating(Object valueToUpdate)
        Factory method for constructing ObjectReader that will update given Object (usually Bean, but can be a Collection or Map as well, but NOT an array) with JSON data. Deserialization occurs normally except that the root-level value in JSON is not used for instantiating a new object; instead give updateable object is used as root. Runtime type of value object is used for locating deserializer, unless overridden by other factory methods of ObjectReader

      • readerFor

        public ObjectReader readerFor(JavaType type)
        Factory method for constructing ObjectReader that will read or update instances of specified type
        Since:
        2.6

      • readerFor

        public ObjectReader readerFor(Class<?> type)
        Factory method for constructing ObjectReader that will read or update instances of specified type
        Since:
        2.6

      • readerFor

        public ObjectReader readerFor(com.fasterxml.jackson.core.type.TypeReference<?> type)
        Factory method for constructing ObjectReader that will read or update instances of specified type
        Since:
        2.6

      • readerForArrayOf

        public ObjectReader readerForArrayOf(Class<?> type)
        Factory method for constructing ObjectReader that will read values of a type List<type>. Functionally same as: 
            readerFor(type[].class);
        Since:
        2.11

      • readerForListOf

        public ObjectReader readerForListOf(Class<?> type)
        Factory method for constructing ObjectReader that will read or update instances of a type List<type>. Functionally same as: 
            readerFor(new TypeReference<List<type>>() { });
        Since:
        2.11

      • readerForMapOf

        public ObjectReader readerForMapOf(Class<?> type)
        Factory method for constructing ObjectReader that will read or update instances of a type Map<String, type> Functionally same as: 
            readerFor(new TypeReference<Map<String, type>>() { });
        Since:
        2.11

      • reader

        public ObjectReader reader(com.fasterxml.jackson.core.FormatSchema schema)
        Factory method for constructing ObjectReader that will pass specific schema object to JsonParser used for reading content.
        Parameters:
        schema - Schema to pass to parser

      • reader

        public ObjectReader reader(InjectableValues injectableValues)
        Factory method for constructing ObjectReader that will use specified injectable values.
        Parameters:
        injectableValues - Injectable values to use

      • readerWithView

        public ObjectReader readerWithView(Class<?> view)
        Factory method for constructing ObjectReader that will deserialize objects using specified JSON View (filter).

      • reader

        public ObjectReader reader(com.fasterxml.jackson.core.Base64Variant defaultBase64)
        Factory method for constructing ObjectReader that will use specified Base64 encoding variant for Base64-encoded binary data.
        Since:
        2.1

      • convertValue

        public <T> T convertValue(Object fromValue,
                          Class<T> toValueType)
                   throws IllegalArgumentException
        Convenience method for doing two-step conversion from given value, into instance of given value type, by writing value into temporary buffer and reading from the buffer into specified target type.

        This method is functionally similar to first serializing given value into JSON, and then binding JSON data into value of given type, but should be more efficient since full serialization does not (need to) occur. However, same converters (serializers, deserializers) will be used as for data binding, meaning same object mapper configuration works.

        Note that behavior changed slightly between Jackson 2.9 and 2.10 so that whereas earlier some optimizations were used to avoid write/read cycle in case input was of target type, from 2.10 onwards full processing is always performed. See databind#2220 for full details of the change.

        Further note that it is possible that in some cases behavior does differ from full serialize-then-deserialize cycle: in most case differences are unintentional (that is, flaws to fix) and should be reported, but the behavior is not guaranteed to be 100% the same: the goal is to allow efficient value conversions for structurally compatible Objects, according to standard Jackson configuration.

        Finally, this functionality is not designed to support "advanced" use cases, such as conversion of polymorphic values, or cases where Object Identity is used.

        Throws:
        IllegalArgumentException - If conversion fails due to incompatible type; if so, root cause will contain underlying checked exception data binding functionality threw

      • _convert

        protected Object _convert(Object fromValue,
                          JavaType toValueType)
                   throws IllegalArgumentException
        Actual conversion implementation: instead of using existing read and write methods, much of code is inlined. Reason for this is that we must avoid root value wrapping/unwrapping both for efficiency and for correctness. If root value wrapping/unwrapping is actually desired, caller must use explicit writeValue and readValue methods.
        Throws:
        IllegalArgumentException

      • updateValue

        public <T> T updateValue(T valueToUpdate,
                         Object overrides)
                  throws JsonMappingException
        Convenience method similar to convertValue(Object, JavaType) but one in which

        Implementation is approximately as follows:

        1. Serialize `updateWithValue` into TokenBuffer
        2. Construct ObjectReader with `valueToUpdate` (using readerForUpdating(Object))
        3. Construct JsonParser (using TokenBuffer.asParser())
        4. Update using ObjectReader.readValue(JsonParser).
        5. Return `valueToUpdate`

        Note that update is "shallow" in that only first level of properties (or, immediate contents of container to update) are modified, unless properties themselves indicate that merging should be applied for contents. Such merging can be specified using annotations (see JsonMerge) as well as using "config overrides" (see configOverride(Class) and setDefaultMergeable(Boolean)).

        Parameters:
        valueToUpdate - Object to update
        overrides - Object to conceptually serialize and merge into value to update; can be thought of as a provider for overrides to apply.
        Returns:
        Either the first argument (`valueToUpdate`), if it is mutable; or a result of creating new instance that is result of "merging" values (for example, "updating" a Java array will create a new array)
        Throws:
        JsonMappingException - if there are structural incompatibilities that prevent update.
        Since:
        2.9

      • acceptJsonFormatVisitor

        public void acceptJsonFormatVisitor(Class<?> type,
                                    JsonFormatVisitorWrapper visitor)
                             throws JsonMappingException
        Method for visiting type hierarchy for given type, using specified visitor.

        This method can be used for things like generating JSON Schema instance for specified type.

        Parameters:
        type - Type to generate schema for (possibly with generic signature)
        Throws:
        JsonMappingException
        Since:
        2.1

      • acceptJsonFormatVisitor

        public void acceptJsonFormatVisitor(JavaType type,
                                    JsonFormatVisitorWrapper visitor)
                             throws JsonMappingException
        Method for visiting type hierarchy for given type, using specified visitor. Visitation uses Serializer hierarchy and related properties

        This method can be used for things like generating JSON Schema instance for specified type.

        Parameters:
        type - Type to generate schema for (possibly with generic signature)
        Throws:
        JsonMappingException
        Since:
        2.1

      • _writeValueAndClose

        protected final void _writeValueAndClose(com.fasterxml.jackson.core.JsonGenerator g,
                                         Object value)
                                  throws IOException
        Method called to configure the generator as necessary and then call write functionality
        Throws:
        IOException
        Since:
        2.11.2

      • _initForReading

        protected com.fasterxml.jackson.core.JsonToken _initForReading(com.fasterxml.jackson.core.JsonParser p,
                                                               JavaType targetType)
                                                        throws IOException
        Method called to ensure that given parser is ready for reading content for data binding.
        Returns:
        First token to be used for data binding after this call: can never be null as exception will be thrown if parser cannot provide more tokens.
        Throws:
        IOException - if the underlying input source has problems during parsing
        com.fasterxml.jackson.core.JsonParseException - if parser has problems parsing content
        JsonMappingException - if the parser does not have any more content to map (note: Json "null" value is considered content; enf-of-stream not)

      • _initForReading

        @Deprecated
protected com.fasterxml.jackson.core.JsonToken _initForReading(com.fasterxml.jackson.core.JsonParser p)
                                                                    throws IOException
        Deprecated. 
        Throws:
        IOException

      • _verifySchemaType

        protected void _verifySchemaType(com.fasterxml.jackson.core.FormatSchema schema)
        Since:
        2.2

      • _assertNotNull

        protected final void _assertNotNull(String paramName,
                                    Object src)

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