public enum SerializationFeature extends Enum<SerializationFeature> implements ConfigFeature
Note that features can be set both through
ObjectMapper
(as sort of defaults) and through
ObjectWriter
.
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 ObjectWriter
.
Enum Constant and Description |
---|
CLOSE_CLOSEABLE
Feature that determines whether
close method of
serialized root level objects (ones for which ObjectMapper 's
writeValue() (or equivalent) method is called)
that implement Closeable
is called after serialization or not. |
EAGER_SERIALIZER_FETCH
Feature that determines whether
ObjectWriter should
try to eagerly fetch necessary JsonSerializer when
possible. |
FAIL_ON_EMPTY_BEANS
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).
|
FAIL_ON_SELF_REFERENCES
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). |
FLUSH_AFTER_WRITE_VALUE
Feature that determines whether
JsonGenerator.flush() is
called after writeValue() method that takes JsonGenerator
as an argument completes (i.e. |
INDENT_OUTPUT
Feature that allows enabling (or disabling) indentation
for the underlying generator, using the default pretty
printer (see
JsonGenerator.useDefaultPrettyPrinter()
for details). |
ORDER_MAP_ENTRIES_BY_KEYS
|
USE_EQUALITY_FOR_OBJECT_ID
Feature that determines whether Object Identity is compared using
true JVM-level identity of Object (false); or,
equals() method. |
WRAP_EXCEPTIONS
|
WRAP_ROOT_VALUE
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.
|
WRITE_BIGDECIMAL_AS_PLAIN
Feature that determines whether
BigDecimal entries are
serialized using BigDecimal.toPlainString() to prevent
values to be written using scientific notation. |
WRITE_CHAR_ARRAYS_AS_JSON_ARRAYS
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). |
WRITE_DATE_KEYS_AS_TIMESTAMPS
|
WRITE_DATE_TIMESTAMPS_AS_NANOSECONDS
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.
|
WRITE_DATES_AS_TIMESTAMPS
|
WRITE_EMPTY_JSON_ARRAYS
Feature that determines whether Container properties (POJO properties
with declared value of Collection or array; i.e.
|
WRITE_ENUMS_USING_INDEX
Feature that determines whethere Java Enum values are serialized
as numbers (true), or textual values (false).
|
WRITE_ENUMS_USING_TO_STRING
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. |
WRITE_NULL_MAP_VALUES
Feature that determines whether Map entries with null values are
to be serialized (true) or not (false).
|
WRITE_SINGLE_ELEM_ARRAYS_UNWRAPPED
Feature added for interoperability, to work with oddities of
so-called "BadgerFish" convention.
|
Modifier and Type | Method and Description |
---|---|
boolean |
enabledByDefault()
Accessor for checking whether this feature is enabled by default.
|
int |
getMask()
Returns bit mask for this feature instance
|
static SerializationFeature |
valueOf(String name)
Returns the enum constant of this type with the specified name.
|
static SerializationFeature[] |
values()
Returns an array containing the constants of this enum type, in
the order they are declared.
|
public static final SerializationFeature WRAP_ROOT_VALUE
@XmlRootElement.name
) or fallback (non-qualified
class name).
Feature is mostly intended for JAXB compatibility.
Feature is disabled by default.
public static final SerializationFeature INDENT_OUTPUT
JsonGenerator.useDefaultPrettyPrinter()
for details).
Note that this only affects cases where
JsonGenerator
is constructed implicitly by ObjectMapper: if explicit
generator is passed, its configuration is not changed.
Also note that if you want to configure details of indentation,
you need to directly configure the generator: there is a
method to use any PrettyPrinter
instance.
This feature will only allow using the default implementation.
Feature is enabled by default.
public static final SerializationFeature FAIL_ON_EMPTY_BEANS
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.
public static final SerializationFeature FAIL_ON_SELF_REFERENCES
JsonMappingException
is
thrown (if true), or reference is normally processed (false).
Feature is enabled by default.
public static final SerializationFeature WRAP_EXCEPTIONS
Exception
s (but never Error
s!)
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 IOException
s 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.
public static final SerializationFeature CLOSE_CLOSEABLE
close
method of
serialized root level objects (ones for which ObjectMapper
's
writeValue() (or equivalent) method is called)
that implement 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.
NOTE: only affects behavior with root objects, and not other objects reachable from the root object. Put another way, only one call will be made for each 'writeValue' call.
Feature is disabled by default.
public static final SerializationFeature FLUSH_AFTER_WRITE_VALUE
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.
public static final SerializationFeature WRITE_DATES_AS_TIMESTAMPS
Date
values
(and Date-based things like Calendar
s) are to be
serialized as numeric timestamps (true; the default),
or as something else (usually textual representation).
If textual representation is used, the actual format is
one returned by a call to
MapperConfig.getDateFormat()
:
the default setting being StdDateFormat
,
which corresponds to format String of "yyyy-MM-dd'T'HH:mm:ss.SSSZ"
(see DateFormat
for details of format Strings).
Note: whether this feature affects handling of other date-related types depend on handlers of those types, although ideally they should use this feature
Note: whether Map
keys are serialized as Strings
or not is controlled using WRITE_DATE_KEYS_AS_TIMESTAMPS
.
Feature is enabled by default.
public static final SerializationFeature WRITE_DATE_KEYS_AS_TIMESTAMPS
public static final SerializationFeature WRITE_CHAR_ARRAYS_AS_JSON_ARRAYS
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.
public static final SerializationFeature WRITE_ENUMS_USING_TO_STRING
Enum.toString()
is used; if disabled, return value of Enum.name()
is used.
Note: this feature should usually have same value
as DeserializationFeature.READ_ENUMS_USING_TO_STRING
.
Feature is disabled by default.
public static final SerializationFeature WRITE_ENUMS_USING_INDEX
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.
Feature is disabled by default.
public static final SerializationFeature WRITE_NULL_MAP_VALUES
For further details, check out [JACKSON-314]
Feature is enabled by default.
public static final SerializationFeature WRITE_EMPTY_JSON_ARRAYS
Note that this does not change behavior of Map
s, or
"Collection-like" types.
Feature is enabled by default.
public static final SerializationFeature WRITE_SINGLE_ELEM_ARRAYS_UNWRAPPED
Collection
s
and arrays: if enabled, Collection
s 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 ] }will instead be serialized as
{ "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.
public static final SerializationFeature WRITE_BIGDECIMAL_AS_PLAIN
BigDecimal
entries are
serialized using BigDecimal.toPlainString()
to prevent
values to be written using scientific notation.
NOTE: since this feature typically requires use of
JsonGenerator.writeNumber(String)
ot may cause compatibility problems since not all JsonGenerator
implementations support such mode of output: usually only text-based formats
support it.
Feature is disabled by default.
public static final SerializationFeature WRITE_DATE_TIMESTAMPS_AS_NANOSECONDS
If disabled, standard millisecond timestamps are assumed.
This is the counterpart to WRITE_DATE_TIMESTAMPS_AS_NANOSECONDS
.
Feature is enabled by default, to support most accurate time values possible.
public static final SerializationFeature ORDER_MAP_ENTRIES_BY_KEYS
public static final SerializationFeature EAGER_SERIALIZER_FETCH
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.
public static final SerializationFeature USE_EQUALITY_FOR_OBJECT_ID
equals()
method.
Latter is sometimes useful when dealing with Database-bound objects with
ORM libraries (like Hibernate).
Feature is disabled by default; meaning that strict identity is used, not
equals()
public static SerializationFeature[] values()
for (SerializationFeature c : SerializationFeature.values()) System.out.println(c);
public static SerializationFeature valueOf(String name)
name
- the name of the enum constant to be returned.IllegalArgumentException
- if this enum type has no constant
with the specified nameNullPointerException
- if the argument is nullpublic boolean enabledByDefault()
ConfigFeature
enabledByDefault
in interface ConfigFeature
public int getMask()
ConfigFeature
getMask
in interface ConfigFeature
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