MapDeserializer (jackson-databind 2.5.2)

java.lang.Object
- com.fasterxml.jackson.databind.JsonDeserializer<T>
- - com.fasterxml.jackson.databind.deser.std.StdDeserializer<T>
  - - com.fasterxml.jackson.databind.deser.std.ContainerDeserializerBase<Map<Object,Object>>
    - - com.fasterxml.jackson.databind.deser.std.MapDeserializer

All Implemented Interfaces:

ContextualDeserializer, ResolvableDeserializer, Serializable
```
public class MapDeserializer
extends ContainerDeserializerBase<Map<Object,Object>>
implements ContextualDeserializer, ResolvableDeserializer
```
Basic serializer that can take JSON "Object" structure and construct a Map instance, with typed contents.
Note: for untyped content (one indicated by passing Object.class as the type), UntypedObjectDeserializer is used instead. It can also construct Maps, but not with specific POJO types, only other containers and primitives/wrappers.

See Also:
Serialized Form

Nested Class Summary
- Nested classes/interfaces inherited from class com.fasterxml.jackson.databind.JsonDeserializer
  JsonDeserializer.None

Field Summary

Fields
Modifier and Type	Field and Description
`protected JsonDeserializer<Object>`	`_delegateDeserializer` Deserializer that is used iff delegate-based creator is to be used for deserializing from JSON Object.
`protected boolean`	`_hasDefaultCreator`
`protected HashSet<String>`	`_ignorableProperties`
`protected KeyDeserializer`	`_keyDeserializer` Key deserializer to use; either passed via constructor (when indicated by annotations), or resolved when `resolve(com.fasterxml.jackson.databind.DeserializationContext)` is called;
`protected JavaType`	`_mapType`
`protected PropertyBasedCreator`	`_propertyBasedCreator` If the Map is to be instantiated using non-default constructor or factory method that takes one or more named properties as argument(s), this creator is used for instantiation.
`protected boolean`	`_standardStringKey` Flag set to indicate that the key type is `String` (or `Object`, for which String is acceptable), and that the default Jackson key deserializer would be used.
`protected JsonDeserializer<Object>`	`_valueDeserializer` Value deserializer.
`protected ValueInstantiator`	`_valueInstantiator`
`protected TypeDeserializer`	`_valueTypeDeserializer` If value instances have polymorphic type information, this is the type deserializer that can handle it

Fields inherited from class com.fasterxml.jackson.databind.deser.std.StdDeserializer
_valueClass

Constructor Summary

Constructors
Modifier	Constructor and Description
	`MapDeserializer(JavaType mapType, ValueInstantiator valueInstantiator, KeyDeserializer keyDeser, JsonDeserializer<Object> valueDeser, TypeDeserializer valueTypeDeser)`
`protected`	`MapDeserializer(MapDeserializer src)` Copy-constructor that can be used by sub-classes to allow copy-on-write styling copying of settings of an existing instance.
`protected`	`MapDeserializer(MapDeserializer src, KeyDeserializer keyDeser, JsonDeserializer<Object> valueDeser, TypeDeserializer valueTypeDeser, HashSet<String> ignorable)`

Method Summary

Methods
Modifier and Type	Method and Description
`Map<Object,Object>`	`_deserializeUsingCreator(JsonParser jp, DeserializationContext ctxt)`
`protected boolean`	`_isStdKeyDeser(JavaType mapType, KeyDeserializer keyDeser)` Helper method used to check whether we can just use the default key deserialization, where JSON String becomes Java String.
`protected void`	`_readAndBind(JsonParser jp, DeserializationContext ctxt, Map<Object,Object> result)`
`protected void`	`_readAndBindStringMap(JsonParser jp, DeserializationContext ctxt, Map<Object,Object> result)` Optimized method used when keys can be deserialized as plain old `String`s, and there is no custom deserialized specified.
`JsonDeserializer<?>`	`createContextual(DeserializationContext ctxt, BeanProperty property)` Method called to finalize setup of this deserializer, when it is known for which property deserializer is needed for.
`Map<Object,Object>`	`deserialize(JsonParser jp, DeserializationContext ctxt)` Method that can be called to ask implementation to deserialize JSON content into the value type this serializer handles.
`Map<Object,Object>`	`deserialize(JsonParser p, DeserializationContext ctxt, Map<Object,Object> result)` Alternate deserialization method (compared to the most commonly used, `JsonDeserializer.deserialize(JsonParser, DeserializationContext)`), which takes in initialized value instance, to be configured and/or populated by deserializer.
`Object`	`deserializeWithType(JsonParser jp, DeserializationContext ctxt, TypeDeserializer typeDeserializer)` Base implementation that does not assume specific type inclusion mechanism.
`JsonDeserializer<Object>`	`getContentDeserializer()` Accesor for deserializer use for deserializing content values.
`JavaType`	`getContentType()` Accessor for declared type of contained value elements; either exact type, or one of its supertypes.
`Class<?>`	`getMapClass()`
`JavaType`	`getValueType()` Exact structured type deserializer handles, if known.
`boolean`	`isCachable()` Turns out that these are expensive enough to create so that caching does make sense.
`void`	`resolve(DeserializationContext ctxt)` Method called after deserializer instance has been constructed (and registered as necessary by provider objects), but before it has returned it to the caller.
`void`	`setIgnorableProperties(String[] ignorable)`
`protected MapDeserializer`	`withResolved(KeyDeserializer keyDeser, TypeDeserializer valueTypeDeser, JsonDeserializer<?> valueDeser, HashSet<String> ignorable)` Fluent factory method used to create a copy with slightly different settings.
`protected void`	`wrapAndThrow(Throwable t, Object ref)` Deprecated.

Methods inherited from class com.fasterxml.jackson.databind.deser.std.ContainerDeserializerBase
findBackReference, wrapAndThrow

Methods inherited from class com.fasterxml.jackson.databind.deser.std.StdDeserializer
_deserializeFromEmpty, _hasTextualNull, _isNaN, _isNegInf, _isPosInf, _parseBoolean, _parseBooleanFromNumber, _parseBooleanPrimitive, _parseByte, _parseDate, _parseDouble, _parseDoublePrimitive, _parseFloat, _parseFloatPrimitive, _parseInteger, _parseIntPrimitive, _parseLong, _parseLongPrimitive, _parseShort, _parseShortPrimitive, _parseString, findConvertingContentDeserializer, findDeserializer, getValueClass, handledType, handleUnknownProperty, isDefaultDeserializer, isDefaultKeyDeserializer, parseDouble

Methods inherited from class com.fasterxml.jackson.databind.JsonDeserializer
getDelegatee, getEmptyValue, getKnownPropertyNames, getNullValue, getObjectIdReader, replaceDelegatee, unwrappingDeserializer

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - _mapType
```
protected final JavaType _mapType
```
  - _keyDeserializer
```
protected final KeyDeserializer _keyDeserializer
```
    Key deserializer to use; either passed via constructor (when indicated by annotations), or resolved when resolve(com.fasterxml.jackson.databind.DeserializationContext) is called;
  - _standardStringKey
```
protected boolean _standardStringKey
```
    Flag set to indicate that the key type is String (or Object, for which String is acceptable), and that the default Jackson key deserializer would be used. If both are true, can optimize handling.
  - _valueDeserializer
```
protected final JsonDeserializer<Object> _valueDeserializer
```
    Value deserializer.
  - _valueTypeDeserializer
```
protected final TypeDeserializer _valueTypeDeserializer
```
    If value instances have polymorphic type information, this is the type deserializer that can handle it
  - _valueInstantiator
```
protected final ValueInstantiator _valueInstantiator
```
  - _hasDefaultCreator
```
protected final boolean _hasDefaultCreator
```
  - _delegateDeserializer
```
protected JsonDeserializer<Object> _delegateDeserializer
```
    Deserializer that is used iff delegate-based creator is to be used for deserializing from JSON Object.
  - _propertyBasedCreator
```
protected PropertyBasedCreator _propertyBasedCreator
```
    If the Map is to be instantiated using non-default constructor or factory method that takes one or more named properties as argument(s), this creator is used for instantiation.
  - _ignorableProperties
```
protected HashSet<String> _ignorableProperties
```
- Constructor Detail
  - MapDeserializer
```
public MapDeserializer(JavaType mapType,
               ValueInstantiator valueInstantiator,
               KeyDeserializer keyDeser,
               JsonDeserializer<Object> valueDeser,
               TypeDeserializer valueTypeDeser)
```
  - MapDeserializer
```
protected MapDeserializer(MapDeserializer src)
```
    Copy-constructor that can be used by sub-classes to allow copy-on-write styling copying of settings of an existing instance.
  - MapDeserializer
```
protected MapDeserializer(MapDeserializer src,
               KeyDeserializer keyDeser,
               JsonDeserializer<Object> valueDeser,
               TypeDeserializer valueTypeDeser,
               HashSet<String> ignorable)
```
- Method Detail
  - withResolved
```
protected MapDeserializer withResolved(KeyDeserializer keyDeser,
                           TypeDeserializer valueTypeDeser,
                           JsonDeserializer<?> valueDeser,
                           HashSet<String> ignorable)
```
    Fluent factory method used to create a copy with slightly different settings. When sub-classing, MUST be overridden.
  - _isStdKeyDeser
```
protected final boolean _isStdKeyDeser(JavaType mapType,
                     KeyDeserializer keyDeser)
```
    Helper method used to check whether we can just use the default key deserialization, where JSON String becomes Java String.
  - setIgnorableProperties
```
public void setIgnorableProperties(String[] ignorable)
```
  - resolve
```
public void resolve(DeserializationContext ctxt)
             throws JsonMappingException
```
    Description copied from interface: ResolvableDeserializer
    
    Method called after deserializer instance has been constructed (and registered as necessary by provider objects), but before it has returned it to the caller. Called object can then resolve its dependencies to other types, including self-references (direct or indirect).
    
    Specified by:
    
    resolve in interface ResolvableDeserializer
    
    Parameters:
    ctxt - Context to use for accessing configuration, resolving secondary deserializers
    
    Throws:
    
    JsonMappingException
  - createContextual
```
public JsonDeserializer<?> createContextual(DeserializationContext ctxt,
                                   BeanProperty property)
                                     throws JsonMappingException
```
    Method called to finalize setup of this deserializer, when it is known for which property deserializer is needed for.
    
    Specified by:
    
    createContextual in interface ContextualDeserializer
    
    Parameters:
    ctxt - Deserialization context to access configuration, additional deserializers that may be needed by this deserializer
    property - Method, field or constructor parameter that represents the property (and is used to assign deserialized value). Should be available; but there may be cases where caller can not provide it and null is passed instead (in which case impls usually pass 'this' deserializer as is)
    
    Returns:
    Deserializer to use for deserializing values of specified property; may be this instance or a new instance.
    
    Throws:
    
    JsonMappingException
  - getContentType
```
public JavaType getContentType()
```
    Description copied from class: ContainerDeserializerBase
    
    Accessor for declared type of contained value elements; either exact type, or one of its supertypes.
    
    Specified by:
    
    getContentType in class ContainerDeserializerBase<Map<Object,Object>>
  - getContentDeserializer
```
public JsonDeserializer<Object> getContentDeserializer()
```
    Description copied from class: ContainerDeserializerBase
    
    Accesor for deserializer use for deserializing content values.
    
    Specified by:
    
    getContentDeserializer in class ContainerDeserializerBase<Map<Object,Object>>
  - isCachable
```
public boolean isCachable()
```
    Turns out that these are expensive enough to create so that caching does make sense.
    IMPORTANT: but, note, that instances CAN NOT BE CACHED if there is a value type deserializer; this caused an issue with 2.4.4 of JAXB Annotations (failing a test). It is also possible that some other settings could make deserializers un-cacheable; but on the other hand, caching can make a big positive difference with performance... so it's a hard choice.
    
    Overrides:
    
    isCachable in class JsonDeserializer<Map<Object,Object>>
    
    Since:
    
    2.4.4
  - deserialize
```
public Map<Object,Object> deserialize(JsonParser jp,
                             DeserializationContext ctxt)
                               throws IOException,
                                      JsonProcessingException
```
    Description copied from class: JsonDeserializer
    Method that can be called to ask implementation to deserialize JSON content into the value type this serializer handles. Returned instance is to be constructed by method itself.
    Pre-condition for this method is that the parser points to the first event that is part of value to deserializer (and which is never JSON 'null' literal, more on this below): for simple types it may be the only value; and for structured types the Object start marker or a FIELD_NAME.
    
    The two possible input conditions for structured types result from polymorphism via fields. In the ordinary case, Jackson calls this method when it has encountered an OBJECT_START, and the method implementation must advance to the next token to see the first field name. If the application configures polymorphism via a field, then the object looks like the following.
```
      {
          "@class": "class name",
          ...
      }
  
```
    Jackson consumes the two tokens (the @class field name and its value) in order to learn the class and select the deserializer. Thus, the stream is pointing to the FIELD_NAME for the first field after the @class. Thus, if you want your method to work correctly both with and without polymorphism, you must begin your method with:
```
       if (jp.getCurrentToken() == JsonToken.START_OBJECT) {
         jp.nextToken();
       }
  
```
    This results in the stream pointing to the field name, so that the two conditions align.
    
    Post-condition is that the parser will point to the last event that is part of deserialized value (or in case deserialization fails, event that was not recognized or usable, which may be the same event as the one it pointed to upon call).
    Note that this method is never called for JSON null literal, and thus deserializers need (and should) not check for it.
    Specified by:
    
    deserialize in class JsonDeserializer<Map<Object,Object>>
    
    Parameters:
    jp - Parsed used for reading JSON content
    ctxt - Context that can be used to access information about this deserialization activity.
    
    Returns:
    Deserialized value
    
    Throws:
    
    IOException
    
    JsonProcessingException
  - deserialize
```
public Map<Object,Object> deserialize(JsonParser p,
                             DeserializationContext ctxt,
                             Map<Object,Object> result)
                               throws IOException
```
    Description copied from class: JsonDeserializer
    
    Alternate deserialization method (compared to the most commonly used, JsonDeserializer.deserialize(JsonParser, DeserializationContext)), which takes in initialized value instance, to be configured and/or populated by deserializer. Method is not necessarily used (or supported) by all types (it will not work for immutable types, for obvious reasons): most commonly it is used for Collections and Maps. It may be used both with "updating readers" (for POJOs) and when Collections and Maps use "getter as setter".
    Default implementation just throws UnsupportedOperationException, to indicate that types that do not explicitly add support do not necessarily support update-existing-value operation (esp. immutable types)
    
    Overrides:
    
    deserialize in class JsonDeserializer<Map<Object,Object>>
    
    Throws:
    
    IOException
  - deserializeWithType
```
public Object deserializeWithType(JsonParser jp,
                         DeserializationContext ctxt,
                         TypeDeserializer typeDeserializer)
                           throws IOException,
                                  JsonProcessingException
```
    Description copied from class: StdDeserializer
    
    Base implementation that does not assume specific type inclusion mechanism. Sub-classes are expected to override this method if they are to handle type information.
    
    Overrides:
    
    deserializeWithType in class StdDeserializer<Map<Object,Object>>
    
    typeDeserializer - Deserializer to use for handling type information
    
    Throws:
    
    IOException
    
    JsonProcessingException
  - getMapClass
```
public final Class<?> getMapClass()
```
  - getValueType
```
public JavaType getValueType()
```
    Description copied from class: StdDeserializer
    
    Exact structured type deserializer handles, if known.
    Default implementation just returns null.
    
    Overrides:
    
    getValueType in class StdDeserializer<Map<Object,Object>>
  - _readAndBind
```
protected final void _readAndBind(JsonParser jp,
                DeserializationContext ctxt,
                Map<Object,Object> result)
                           throws IOException,
                                  JsonProcessingException
```
    Throws:
    
    IOException
    
    JsonProcessingException
  - _readAndBindStringMap
```
protected final void _readAndBindStringMap(JsonParser jp,
                         DeserializationContext ctxt,
                         Map<Object,Object> result)
                                    throws IOException,
                                           JsonProcessingException
```
    Optimized method used when keys can be deserialized as plain old Strings, and there is no custom deserialized specified.
    
    Throws:
    
    IOException
    
    JsonProcessingException
  - _deserializeUsingCreator
```
public Map<Object,Object> _deserializeUsingCreator(JsonParser jp,
                                          DeserializationContext ctxt)
                                            throws IOException,
                                                   JsonProcessingException
```
    Throws:
    
    IOException
    
    JsonProcessingException
  - wrapAndThrow
```
@Deprecated
protected void wrapAndThrow(Throwable t,
                           Object ref)
                     throws IOException
```
    Deprecated.
    
    Throws:
    
    IOException

Class MapDeserializer

Nested Class Summary

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

Field Summary

Fields inherited from class com.fasterxml.jackson.databind.deser.std.StdDeserializer

Constructor Summary

Method Summary

Methods inherited from class com.fasterxml.jackson.databind.deser.std.ContainerDeserializerBase

Methods inherited from class com.fasterxml.jackson.databind.deser.std.StdDeserializer

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

Methods inherited from class java.lang.Object

Field Detail

_mapType

_keyDeserializer

_standardStringKey

_valueDeserializer

_valueTypeDeserializer

_valueInstantiator

_hasDefaultCreator

_delegateDeserializer

_propertyBasedCreator

_ignorableProperties

Constructor Detail

MapDeserializer

MapDeserializer

MapDeserializer

Method Detail

withResolved

_isStdKeyDeser

setIgnorableProperties

resolve

createContextual

getContentType

getContentDeserializer

isCachable

deserialize

deserialize

deserializeWithType

getMapClass

getValueType

_readAndBind

_readAndBindStringMap

_deserializeUsingCreator

wrapAndThrow