DeserializationFeature (jackson-databind 2.6.0 API)

java.lang.Object
- java.lang.Enum<DeserializationFeature>
- - com.fasterxml.jackson.databind.DeserializationFeature

All Implemented Interfaces:

ConfigFeature, Serializable, Comparable<DeserializationFeature>
```
public enum DeserializationFeature
extends Enum<DeserializationFeature>
implements ConfigFeature
```
Enumeration that defines simple on/off features that affect the way Java objects are deserialized from JSON
Note that features can be set both through ObjectMapper (as sort of defaults) and through ObjectReader. In first case these defaults must follow "config-then-use" patterns (i.e. defined once, not changed afterwards); all per-call changes must be done using ObjectReader.
Note that features that do not indicate version of inclusion were available in Jackson 2.0 (or earlier); only later additions indicate version of inclusion.

Enum Constant Summary

Enum Constants
Enum Constant and Description
`ACCEPT_EMPTY_ARRAY_AS_NULL_OBJECT` Feature that can be enabled to allow empty JSON Array value (that is, `[ ]`) to be bound to POJOs as null.
`ACCEPT_EMPTY_STRING_AS_NULL_OBJECT` Feature that can be enabled to allow JSON empty String value ("") to be bound to POJOs as null.
`ACCEPT_FLOAT_AS_INT` Feature that determines whether coercion from JSON floating point number (anything with command (`.`) or exponent portion (`e` / `E')) to an expected integral number (`int`, `long`, `java.lang.Integer`, `java.lang.Long`, `java.math.BigDecimal`) is allowed or not.
`ACCEPT_SINGLE_VALUE_AS_ARRAY` Feature that determines whether it is acceptable to coerce non-array (in JSON) values to work with Java collection (arrays, java.util.Collection) types.
`ADJUST_DATES_TO_CONTEXT_TIME_ZONE` Feature that specifies whether context provided `TimeZone` (`DeserializationContext.getTimeZone()` should be used to adjust Date/Time values on deserialization, even if value itself contains timezone information.
`EAGER_DESERIALIZER_FETCH` Feature that determines whether `ObjectReader` should try to eagerly fetch necessary `JsonDeserializer` when possible.
`FAIL_ON_IGNORED_PROPERTIES` Feature that determines what happens when a property that has been explicitly marked as ignorable is encountered in input: if feature is enabled, `JsonMappingException` is thrown; if false, property is quietly skipped.
`FAIL_ON_INVALID_SUBTYPE` Feature that determines what happens when type of a polymorphic value (indicated for example by `JsonTypeInfo`) can not be found (missing) or resolved (invalid class name, unmappable id); if enabled, an exception ir thrown; if false, null value is used instead.
`FAIL_ON_MISSING_CREATOR_PROPERTIES` Feature that determines what happens if one or more Creator properties (properties bound to parameters of Creator method (constructor or static factory method)) are missing value to bind to from content.
`FAIL_ON_NULL_FOR_PRIMITIVES` Feature that determines whether encountering of JSON null is an error when deserializing into Java primitive types (like 'int' or 'double').
`FAIL_ON_NUMBERS_FOR_ENUMS` Feature that determines whether JSON integer numbers are valid values to be used for deserializing Java enum values.
`FAIL_ON_READING_DUP_TREE_KEY` Feature that determines what happens when reading JSON content into tree (`TreeNode`) and a duplicate key is encountered (property name that was already seen for the JSON Object).
`FAIL_ON_UNKNOWN_PROPERTIES` Feature that determines whether encountering of unknown properties (ones that do not map to a property, and there is no "any setter" or handler that can handle it) should result in a failure (by throwing a `JsonMappingException`) or not.
`FAIL_ON_UNRESOLVED_OBJECT_IDS` Feature that determines what happens if an Object Id reference is encountered that does not refer to an actual Object with that id ("unresolved Object Id"): either an exception is thrown (`true`), or a null object is used instead (`false`).
`READ_DATE_TIMESTAMPS_AS_NANOSECONDS` Feature that controls whether numeric timestamp values are expected to be written using nanosecond timestamps (enabled) or not (disabled), if and only if datatype supports such resolution.
`READ_ENUMS_USING_TO_STRING` Feature that determines standard deserialization mechanism used for Enum values: if enabled, Enums are assumed to have been serialized using return value of `Enum.toString()`; if disabled, return value of `Enum.name()` is assumed to have been used.
`READ_UNKNOWN_ENUM_VALUES_AS_NULL` Feature that allows unknown Enum values to be parsed as null values.
`UNWRAP_ROOT_VALUE` Feature to allow "unwrapping" root-level JSON value, to match setting of `SerializationFeature.WRAP_ROOT_VALUE` used for serialization.
`UNWRAP_SINGLE_VALUE_ARRAYS` Feature that determines whether it is acceptable to coerce single value array (in JSON) values to the corresponding value type.
`USE_BIG_DECIMAL_FOR_FLOATS` Feature that determines whether JSON floating point numbers are to be deserialized into `BigDecimal`s if only generic type description (either `Object` or `Number`, or within untyped `Map` or `Collection` context) is available.
`USE_BIG_INTEGER_FOR_INTS` Feature that determines whether JSON integral (non-floating-point) numbers are to be deserialized into `BigInteger`s if only generic type description (either `Object` or `Number`, or within untyped `Map` or `Collection` context) is available.
`USE_JAVA_ARRAY_FOR_JSON_ARRAY` Feature that determines whether JSON Array is mapped to `Object[]` or `List<Object>` when binding "untyped" objects (ones with nominal type of `java.lang.Object`).
`USE_LONG_FOR_INTS` Feature that determines how "small" JSON integral (non-floating-point) numbers -- ones that fit in 32-bit signed integer (`int`) -- are bound when target type is loosely typed as `Object` or `Number` (or within untyped `Map` or `Collection` context).
`WRAP_EXCEPTIONS` Feature that determines whether Jackson code should catch and wrap `Exception`s (but never `Error`s!) to add additional information about location (within input) of problem or not.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`enabledByDefault()` Accessor for checking whether this feature is enabled by default.
`boolean`	`enabledIn(int flags)` Convenience method for checking whether feature is enabled in given bitmask
`int`	`getMask()` Returns bit mask for this feature instance
`static DeserializationFeature`	`valueOf(String name)` Returns the enum constant of this type with the specified name.
`static DeserializationFeature[]`	`values()` Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum
clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait

- Enum Constant Detail
  - USE_BIG_DECIMAL_FOR_FLOATS
```
public static final DeserializationFeature USE_BIG_DECIMAL_FOR_FLOATS
```
    Feature that determines whether JSON floating point numbers are to be deserialized into BigDecimals if only generic type description (either Object or Number, or within untyped Map or Collection context) is available. If enabled such values will be deserialized as BigDecimals; if disabled, will be deserialized as Doubles.
    Feature is disabled by default, meaning that "untyped" floating point numbers will by default be deserialized as Doubles (choice is for performance reason -- BigDecimals are slower than Doubles).
  - USE_BIG_INTEGER_FOR_INTS
```
public static final DeserializationFeature USE_BIG_INTEGER_FOR_INTS
```
    Feature that determines whether JSON integral (non-floating-point) numbers are to be deserialized into BigIntegers if only generic type description (either Object or Number, or within untyped Map or Collection context) is available. If enabled such values will be deserialized as BigIntegers; if disabled, will be deserialized as "smallest" available type, which is either Integer, Long or BigInteger, depending on number of digits.
    Feature is disabled by default, meaning that "untyped" integral numbers will by default be deserialized using whatever is the most compact integral type, to optimize efficiency.
  - USE_LONG_FOR_INTS
```
public static final DeserializationFeature USE_LONG_FOR_INTS
```
    Feature that determines how "small" JSON integral (non-floating-point) numbers -- ones that fit in 32-bit signed integer (`int`) -- are bound when target type is loosely typed as Object or Number (or within untyped Map or Collection context). If enabled, such values will be deserialized as Long; if disabled, they will be deserialized as "smallest" available type, Integer. In addition, if enabled, trying to bind values that do not fit in Long will throw a JsonProcessingException.
    Note: if USE_BIG_INTEGER_FOR_INTS is enabled, it has precedence over this setting, forcing use of BigInteger for all integral values.
    Feature is disabled by default, meaning that "untyped" integral numbers will by default be deserialized using Integer if value fits.
    
    Since:
    
    2.6
  - USE_JAVA_ARRAY_FOR_JSON_ARRAY
```
public static final DeserializationFeature USE_JAVA_ARRAY_FOR_JSON_ARRAY
```
    Feature that determines whether JSON Array is mapped to Object[] or List<Object> when binding "untyped" objects (ones with nominal type of java.lang.Object). If true, binds as Object[]; if false, as List<Object>.
    Feature is disabled by default, meaning that JSON arrays are bound as Lists.
  - READ_ENUMS_USING_TO_STRING
```
public static final DeserializationFeature READ_ENUMS_USING_TO_STRING
```
    Feature that determines standard deserialization mechanism used for Enum values: if enabled, Enums are assumed to have been serialized using return value of Enum.toString(); if disabled, return value of Enum.name() is assumed to have been used.
    Note: this feature should usually have same value as SerializationFeature.WRITE_ENUMS_USING_TO_STRING.
    Feature is disabled by default.
  - FAIL_ON_UNKNOWN_PROPERTIES
```
public static final DeserializationFeature FAIL_ON_UNKNOWN_PROPERTIES
```
    Feature that determines whether encountering of unknown properties (ones that do not map to a property, and there is no "any setter" or handler that can handle it) should result in a failure (by throwing a JsonMappingException) or not. This setting only takes effect after all other handling methods for unknown properties have been tried, and property remains unhandled.
    Feature is enabled by default (meaning that a JsonMappingException will be thrown if an unknown property is encountered).
  - FAIL_ON_NULL_FOR_PRIMITIVES
```
public static final DeserializationFeature FAIL_ON_NULL_FOR_PRIMITIVES
```
    Feature that determines whether encountering of JSON null is an error when deserializing into Java primitive types (like 'int' or 'double'). If it is, a JsonProcessingException is thrown to indicate this; if not, default value is used (0 for 'int', 0.0 for double, same defaulting as what JVM uses).
    Feature is disabled by default.
  - FAIL_ON_NUMBERS_FOR_ENUMS
```
public static final DeserializationFeature FAIL_ON_NUMBERS_FOR_ENUMS
```
    Feature that determines whether JSON integer numbers are valid values to be used for deserializing Java enum values. If set to 'false' numbers are acceptable and are used to map to ordinal() of matching enumeration value; if 'true', numbers are not allowed and a JsonMappingException will be thrown. Latter behavior makes sense if there is concern that accidental mapping from integer values to enums might happen (and when enums are always serialized as JSON Strings)
    Feature is disabled by default.
  - FAIL_ON_INVALID_SUBTYPE
```
public static final DeserializationFeature FAIL_ON_INVALID_SUBTYPE
```
    Feature that determines what happens when type of a polymorphic value (indicated for example by JsonTypeInfo) can not be found (missing) or resolved (invalid class name, unmappable id); if enabled, an exception ir thrown; if false, null value is used instead.
    Feature is enabled by default so that exception is thrown for missing or invalid type information.
    
    Since:
    
    2.2
  - FAIL_ON_READING_DUP_TREE_KEY
```
public static final DeserializationFeature FAIL_ON_READING_DUP_TREE_KEY
```
    Feature that determines what happens when reading JSON content into tree (TreeNode) and a duplicate key is encountered (property name that was already seen for the JSON Object). If enabled, JsonMappingException will be thrown; if disabled, no exception is thrown and the new (later) value overwrites the earlier value.
    Note that this property does NOT affect other aspects of data-binding; that is, no detection is done with respect to POJO properties or Map keys. New features may be added to control additional cases.
    Feature is disabled by default so that no exception is thrown.
    
    Since:
    
    2.3
  - FAIL_ON_IGNORED_PROPERTIES
```
public static final DeserializationFeature FAIL_ON_IGNORED_PROPERTIES
```
    Feature that determines what happens when a property that has been explicitly marked as ignorable is encountered in input: if feature is enabled, JsonMappingException is thrown; if false, property is quietly skipped.
    Feature is disabled by default so that no exception is thrown.
    
    Since:
    
    2.3
  - FAIL_ON_UNRESOLVED_OBJECT_IDS
```
public static final DeserializationFeature FAIL_ON_UNRESOLVED_OBJECT_IDS
```
    Feature that determines what happens if an Object Id reference is encountered that does not refer to an actual Object with that id ("unresolved Object Id"): either an exception is thrown (true), or a null object is used instead (false). Note that if this is set to false, no further processing is done; specifically, if reference is defined via setter method, that method will NOT be called.
    Feature is enabled by default, so that unknown Object Ids will result in an exception being thrown, at the end of deserialization.
    
    Since:
    
    2.5
  - FAIL_ON_MISSING_CREATOR_PROPERTIES
```
public static final DeserializationFeature FAIL_ON_MISSING_CREATOR_PROPERTIES
```
    Feature that determines what happens if one or more Creator properties (properties bound to parameters of Creator method (constructor or static factory method)) are missing value to bind to from content. If enabled, such missing values result in a JsonMappingException being thrown with information on the first one (by index) of missing properties. If disabled, and if property is NOT marked as required, missing Creator properties are filled with null values provided by deserializer for the type of parameter (usually null for Object types, and default value for primitives; but redefinable via custom deserializers).
    Note that having an injectable value counts as "not missing".
    Feature is disabled by default, so that no exception is thrown for missing creator property values, unless they are explicitly marked as `required`.
    
    Since:
    
    2.6
  - WRAP_EXCEPTIONS
```
public static final DeserializationFeature WRAP_EXCEPTIONS
```
    Feature that determines whether Jackson code should catch and wrap Exceptions (but never Errors!) to add additional information about location (within input) of problem or not. If enabled, most exceptions will be caught and re-thrown (exception specifically being that IOExceptions may be passed as is, since they are declared as throwable); this can be convenient both in that all exceptions will be checked and declared, and so there is more contextual information. However, sometimes calling application may just want "raw" unchecked exceptions passed as is.
    Feature is enabled by default.
  - ACCEPT_SINGLE_VALUE_AS_ARRAY
```
public static final DeserializationFeature ACCEPT_SINGLE_VALUE_AS_ARRAY
```
    Feature that determines whether it is acceptable to coerce non-array (in JSON) values to work with Java collection (arrays, java.util.Collection) types. If enabled, collection deserializers will try to handle non-array values as if they had "implicit" surrounding JSON array. This feature is meant to be used for compatibility/interoperability reasons, to work with packages (such as XML-to-JSON converters) that leave out JSON array in cases where there is just a single element in array.
    Feature is disabled by default.
  - UNWRAP_SINGLE_VALUE_ARRAYS
```
public static final DeserializationFeature UNWRAP_SINGLE_VALUE_ARRAYS
```
    Feature that determines whether it is acceptable to coerce single value array (in JSON) values to the corresponding value type. This is basically the opposite of the ACCEPT_SINGLE_VALUE_AS_ARRAY feature. If more than one value is found in the array, a JsonMappingException is thrown.
    Feature is disabled by default
    
    Since:
    
    2.4
  - UNWRAP_ROOT_VALUE
```
public static final DeserializationFeature UNWRAP_ROOT_VALUE
```
    Feature to allow "unwrapping" root-level JSON value, to match setting of SerializationFeature.WRAP_ROOT_VALUE used for serialization. Will verify that the root JSON value is a JSON Object, and that it has a single property with expected root name. If not, a JsonMappingException is thrown; otherwise value of the wrapped property will be deserialized as if it was the root value.
    Feature is disabled by default.
  - ACCEPT_EMPTY_STRING_AS_NULL_OBJECT
```
public static final DeserializationFeature ACCEPT_EMPTY_STRING_AS_NULL_OBJECT
```
    Feature that can be enabled to allow JSON empty String value ("") to be bound to POJOs as null. If disabled, standard POJOs can only be bound from JSON null or JSON Object (standard meaning that no custom deserializers or constructors are defined; both of which can add support for other kinds of JSON values); if enabled, empty JSON String can be taken to be equivalent of JSON null.
    Feature is disabled by default.
  - ACCEPT_EMPTY_ARRAY_AS_NULL_OBJECT
```
public static final DeserializationFeature ACCEPT_EMPTY_ARRAY_AS_NULL_OBJECT
```
    Feature that can be enabled to allow empty JSON Array value (that is, [ ]) to be bound to POJOs as null. If disabled, standard POJOs can only be bound from JSON null or JSON Object (standard meaning that no custom deserializers or constructors are defined; both of which can add support for other kinds of JSON values); if enabled, empty JSON Array will be taken to be equivalent of JSON null.
    Feature is disabled by default.
    
    Since:
    
    2.5
  - ACCEPT_FLOAT_AS_INT
```
public static final DeserializationFeature ACCEPT_FLOAT_AS_INT
```
    Feature that determines whether coercion from JSON floating point number (anything with command (`.`) or exponent portion (`e` / `E')) to an expected integral number (`int`, `long`, `java.lang.Integer`, `java.lang.Long`, `java.math.BigDecimal`) is allowed or not. If enabled, coercion truncates value; if disabled, a JsonMappingException will be thrown.
    Feature is enabled by default.
    
    Since:
    
    2.6
  - READ_UNKNOWN_ENUM_VALUES_AS_NULL
```
public static final DeserializationFeature READ_UNKNOWN_ENUM_VALUES_AS_NULL
```
    Feature that allows unknown Enum values to be parsed as null values. If disabled, unknown Enum values will throw exceptions.
    Note that in some cases this will basically ignore unknown Enum values; this is the keys for keys of EnumMap and values of EnumSet (because nulls are not accepted in these cases).
    Feature is disabled by default.
    
    Since:
    
    2.0
  - READ_DATE_TIMESTAMPS_AS_NANOSECONDS
```
public static final DeserializationFeature READ_DATE_TIMESTAMPS_AS_NANOSECONDS
```
    Feature that controls whether numeric timestamp values are expected to be written using nanosecond timestamps (enabled) or not (disabled), if and only if datatype supports such resolution. Only newer datatypes (such as Java8 Date/Time) support such resolution -- older types (pre-Java8 java.util.Date etc) and Joda do not -- and this setting has no effect on such types.
    If disabled, standard millisecond timestamps are assumed. This is the counterpart to SerializationFeature.WRITE_DATE_TIMESTAMPS_AS_NANOSECONDS.
    Feature is enabled by default, to support most accurate time values possible.
    
    Since:
    
    2.2
  - ADJUST_DATES_TO_CONTEXT_TIME_ZONE
```
public static final DeserializationFeature ADJUST_DATES_TO_CONTEXT_TIME_ZONE
```
    Feature that specifies whether context provided TimeZone (DeserializationContext.getTimeZone() should be used to adjust Date/Time values on deserialization, even if value itself contains timezone information. If enabled, contextual TimeZone will essentially override any other TimeZone information; if disabled, it will only be used if value itself does not contain any TimeZone information.
    
    Since:
    
    2.2
  - EAGER_DESERIALIZER_FETCH
```
public static final DeserializationFeature EAGER_DESERIALIZER_FETCH
```
    Feature that determines whether ObjectReader should try to eagerly fetch necessary JsonDeserializer when possible. This improves performance in cases where similarly configured ObjectReader instance is used multiple times; and should not significantly affect single-use cases.
    Note that there should not be any need to normally disable this feature: only consider that if there are actual perceived problems.
    Feature is enabled by default.
    
    Since:
    
    2.1
- Method Detail
  - values
```
public static DeserializationFeature[] values()
```
    Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:
```
for (DeserializationFeature c : DeserializationFeature.values())
    System.out.println(c);
```
    Returns:
    
    an array containing the constants of this enum type, in the order they are declared
  - valueOf
```
public static DeserializationFeature valueOf(String name)
```
    Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
    
    Parameters:
    
    name - the name of the enum constant to be returned.
    
    Returns:
    
    the enum constant with the specified name
    
    Throws:
    
    IllegalArgumentException - if this enum type has no constant with the specified name
    
    NullPointerException - if the argument is null
  - enabledByDefault
```
public boolean enabledByDefault()
```
    Description copied from interface: ConfigFeature
    
    Accessor for checking whether this feature is enabled by default.
    
    Specified by:
    
    enabledByDefault in interface ConfigFeature
  - getMask
```
public int getMask()
```
    Description copied from interface: ConfigFeature
    
    Returns bit mask for this feature instance
    
    Specified by:
    
    getMask in interface ConfigFeature
  - enabledIn
```
public boolean enabledIn(int flags)
```
    Description copied from interface: ConfigFeature
    
    Convenience method for checking whether feature is enabled in given bitmask
    
    Specified by:
    
    enabledIn in interface ConfigFeature

Enum DeserializationFeature

Enum Constant Summary

Method Summary

Methods inherited from class java.lang.Enum

Methods inherited from class java.lang.Object

Enum Constant Detail

USE_BIG_DECIMAL_FOR_FLOATS

USE_BIG_INTEGER_FOR_INTS

USE_LONG_FOR_INTS

USE_JAVA_ARRAY_FOR_JSON_ARRAY

READ_ENUMS_USING_TO_STRING

FAIL_ON_UNKNOWN_PROPERTIES

FAIL_ON_NULL_FOR_PRIMITIVES

FAIL_ON_NUMBERS_FOR_ENUMS

FAIL_ON_INVALID_SUBTYPE

FAIL_ON_READING_DUP_TREE_KEY

FAIL_ON_IGNORED_PROPERTIES

FAIL_ON_UNRESOLVED_OBJECT_IDS

FAIL_ON_MISSING_CREATOR_PROPERTIES

WRAP_EXCEPTIONS

ACCEPT_SINGLE_VALUE_AS_ARRAY

UNWRAP_SINGLE_VALUE_ARRAYS

UNWRAP_ROOT_VALUE

ACCEPT_EMPTY_STRING_AS_NULL_OBJECT

ACCEPT_EMPTY_ARRAY_AS_NULL_OBJECT

ACCEPT_FLOAT_AS_INT

READ_UNKNOWN_ENUM_VALUES_AS_NULL

READ_DATE_TIMESTAMPS_AS_NANOSECONDS

ADJUST_DATES_TO_CONTEXT_TIME_ZONE

EAGER_DESERIALIZER_FETCH

Method Detail

values

valueOf

enabledByDefault

getMask

enabledIn