public final Enum SerializationFeature

Feature that determines whether close method of serialized root level objects (ones for which ObjectMapper's writeValue() (or equivalent) method is called) that implement java.io.Closeable is called after serialization or not. If enabled, close() will be called after serialization completes (whether succesfully, or due to an error manifested by an exception being thrown). You can think of this as sort of "finally" processing.

Feature is disabled by default.

Feature that determines whether ObjectWriter should try to eagerly fetch necessary JsonSerializer when possible. This improves performance in cases where similarly configured ObjectWriter 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

Feature that determines what happens when no accessors are found for a type (and there are no annotations to indicate it is meant to be serialized). If enabled (default), an exception is thrown to indicate these as non-serializable types; if disabled, they are serialized as empty Objects, i.e. without any properties.

Note that empty types that this feature has only effect on those "empty" beans that do not have any recognized annotations (like @JsonSerialize): ones that do have annotations do not result in an exception being thrown.

Feature is enabled by default.

Feature that determines what happens when a direct self-reference is detected by a POJO (and no Object Id handling is enabled for it): either a JsonMappingException is thrown (if true), or reference is normally processed (false).

Feature is enabled by default.

Since

2.4

Feature that determines what happens when an object which normally has type information included by Jackson is used in conjunction with com.fasterxml.jackson.annotation.JsonUnwrapped. In the default (enabled) state, an error will be thrown when an unwrapped object has type information. When disabled, the object will be unwrapped and the type information discarded.

Feature is enabled by default.

Since

2.4

Feature that determines whether JsonGenerator.flush() is called after writeValue() method that takes JsonGenerator as an argument completes (i.e. does NOT affect methods that use other destinations); same for methods in ObjectWriter. This usually makes sense; but there are cases where flushing should not be forced: for example when underlying stream is compressing and flush() causes compression state to be flushed (which occurs with some compression codecs).

Feature is enabled by default.

Feature that allows enabling (or disabling) indentation for the underlying generator, using the default pretty printer configured for ObjectMapper (and ObjectWriters created from mapper).

Note that the default pretty printer is only used if no explicit com.fasterxml.jackson.core.PrettyPrinter has been configured for the generator or ObjectWriter.

Feature is disabled by default.

Feature that determines whether java.util.Map entries are first sorted by key before serialization or not: if enabled, additional sorting step is performed if necessary (not necessary for java.util.SortedMaps), if disabled, no additional sorting is needed.

Feature is disabled by default.

Feature that determines whether Object Identity is compared using true JVM-level identity of Object (false); or, equals() method. Latter is sometimes useful when dealing with Database-bound objects with ORM libraries (like Hibernate). Note that Object itself is actually compared, and NOT Object Id; naming of this feature is somewhat confusing, so it is important that Object for which identity is to be preserved are considered equal, above and beyond ids (which are always compared using equality anyway).

Feature is disabled by default; meaning that strict identity is used, not equals()

Since

2.3

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 java.io.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.

Feature that can be enabled to make root value (usually JSON Object but can be any type) wrapped within a single property JSON object, where key as the "root name", as determined by annotation introspector (esp. for JAXB that uses @XmlRootElement.name) or fallback (non-qualified class name). Feature is mostly intended for JAXB compatibility.

Feature is disabled by default.

Feature that determines whether java.math.BigDecimal entries are serialized using java.math.BigDecimal#toPlainString() to prevent values to be written using scientific notation.

Feature is disabled by default.

Feature that determines how type char[] is serialized: when enabled, will be serialized as an explict JSON array (with single-character Strings as values); when disabled, defaults to serializing them as Strings (which is more compact).

Feature is disabled by default.

Feature that determines whether java.util.Dates (and sub-types) used as java.util.Map keys are serialized as time stamps or not (if not, will be serialized as textual values).

Default value is 'false', meaning that Date-valued Map keys are serialized as textual (ISO-8601) values.

Feature is disabled by default.

Feature that controls whether numeric timestamp values are 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 DeserializationFeature#READ_DATE_TIMESTAMPS_AS_NANOSECONDS.

Feature is enabled by default, to support most accurate time values possible.

Since

2.2

Feature that determines whether Date (and date/time) values (and Date-based things like java.util.Calendars) are to be serialized as numeric time stamps (true; the default), or as something else (usually textual representation). If textual representation is used, the actual format depends on configuration settings including possible per-property use of @JsonFormat annotation, globally configured java.text.DateFormat.

For "classic" JDK date types (java.util.Date, java.util.Calendar) the default formatting is provided by com.fasterxml.jackson.databind.util.StdDateFormat, and corresponds to format String of "yyyy-MM-dd'T'HH:mm:ss.SSSX" (see java.text.DateFormat for details of format Strings). Whether this feature affects handling of other date-related types depend on handlers of those types, although ideally they should use this feature

Feature is enabled by default, so that date/time are by default serialized as time stamps.

Feature that determines whether timezone/offset included in zoned date/time values (note: does NOT java.util.Date will be overridden if there is an explicitly set context time zone. If disabled, timezone/offset value is used-is; if enabled, context time zone is used instead.

Note that this setting only affects "Zoned" date/time values of Java 8 date/time types -- it will have no effect on old java.util value handling (of which java.util.Date has no timezone information and must use contextual timezone, implicit or explicit; and java.util.Calendar which will always use timezone Calendar value has). Setting is also ignored by Joda date/time values.

Feature is enabled by default for backwards-compatibility purposes (in Jackson 2.12 override was always done if there was explicitly defined timezone).

Since

2.13

Feature that determines whether date/date-time values should be serialized so that they include timezone id, in cases where type itself contains timezone information. Including this information may lead to compatibility issues because ISO-8601 specification does not define formats that include such information.

If enabled, Timezone id should be included using format specified with Java 8 DateTimeFormatter#ISO_ZONED_DATE_TIME definition (for example, '2011-12-03T10:15:30+01:00[Europe/Paris]').

Feature is disabled by default, so that zone id is NOT included; rather, timezone offset is used for ISO-8601 compatibility (if any timezone information is included in value).

Since

2.6

Feature that determines whether time values that represents time periods (durations, periods, ranges) are to be serialized by default using a numeric (true) or textual (false) representations. Note that numeric representation may mean either simple number, or an array of numbers, depending on type.

Feature is enabled by default, so that period/duration are by default serialized as timestamps.

Since

2.5

Feature that determines whether Container properties (POJO properties with declared value of Collection or array; i.e. things that produce JSON arrays) that are empty (have no elements) will be serialized as empty JSON arrays (true), or suppressed from output (false).

Note that this does not change behavior of java.util.Maps, or "Collection-like" types.

Feature is enabled by default.

Feature that determines whether {link Enum}s used as java.util.Map keys are serialized as using Enum#ordinal() or not. Similar to WRITE_ENUMS_USING_INDEX used when writing Enums as regular values.

Feature is disabled by default.

Since

2.10

Feature that determines whether Java Enum values are serialized as numbers (true), or textual values (false). If textual values are used, other settings are also considered. If this feature is enabled, return value of Enum.ordinal() (an integer) will be used as the serialization.

Note that this feature has precedence over WRITE_ENUMS_USING_TO_STRING, which is only considered if this feature is set to false.

Note that since 2.10, this does NOT apply to Enums written as keys of java.util.Map values, which has separate setting, WRITE_ENUM_KEYS_USING_INDEX.

Feature is disabled by default.

Feature that determines standard serialization mechanism used for Enum values: if enabled, return value of Enum.toString() is used; if disabled, return value of Enum.name() is used.

Feature is disabled by default.

Feature that determines whether Map entries with null values are to be serialized (true) or not (false).

Feature is enabled by default.

Feature that determines what happens when a direct self-reference is detected by a POJO (and no Object Id handling is enabled for it): if enabled write that reference as null; if disabled, default behavior is used (which will try to serialize usually resulting in exception). But if SerializationFeature#FAIL_ON_SELF_REFERENCES is enabled. this property is ignored.

Feature is disabled by default.

Since

2.11

Feature added for interoperability, to work with oddities of so-called "BadgerFish" convention. Feature determines handling of single element java.util.Collections and arrays: if enabled, java.util.Collections and arrays that contain exactly one element will be serialized as if that element itself was serialized.

When enabled, a POJO with array that normally looks like this:

  { "arrayProperty" : [ 1 ] }

  { "arrayProperty" : 1 }

Note that this feature is counterpart to DeserializationFeature#ACCEPT_SINGLE_VALUE_AS_ARRAY (that is, usually both are enabled, or neither is).

Feature is disabled by default, so that no special handling is done.