com.fasterxml.jackson.core

Enum JsonGenerator.Feature

java.lang.Object

java.lang.Enum<JsonGenerator.Feature>

com.fasterxml.jackson.core.JsonGenerator.Feature

All Implemented Interfaces:

Serializable, Comparable<JsonGenerator.Feature>

Enclosing class:

JsonGenerator

public static enum JsonGenerator.Feature
extends Enum<JsonGenerator.Feature>

Enumeration that defines all togglable features for generators.

Enum Constant Summary

Enum Constants

Enum Constant and Description
AUTO_CLOSE_JSON_CONTENT Feature that determines what happens when the generator is closed while there are still unmatched JsonToken.START_ARRAY or JsonToken.START_OBJECT entries in output content.
AUTO_CLOSE_TARGET Feature that determines whether generator will automatically close underlying output target that is NOT owned by the generator.
ESCAPE_NON_ASCII Feature that specifies that all characters beyond 7-bit ASCII range (i.e.
FLUSH_PASSED_TO_STREAM Feature that specifies that calls to JsonGenerator.flush() will cause matching flush() to underlying OutputStream or Writer; if disabled this will not be done.
IGNORE_UNKNOWN Feature that determines what to do if the underlying data format requires knowledge of all properties to output, and if no definition is found for a property that caller tries to write.
QUOTE_FIELD_NAMES Feature that determines whether JSON Object field names are quoted using double-quotes, as specified by JSON specification or not.
QUOTE_NON_NUMERIC_NUMBERS Feature that determines whether "exceptional" (not real number) float/double values are output as quoted strings.
STRICT_DUPLICATE_DETECTION Feature that determines whether JsonGenerator will explicitly check that no duplicate JSON Object field names are written.
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_NUMBERS_AS_STRINGS Feature that forces all Java numbers to be written as JSON strings.

Method Summary

Methods

Modifier and Type	Method and Description
static int	collectDefaults() Method that calculates bit set (flags) of all features that are enabled by default.
boolean	enabledByDefault()
boolean	enabledIn(int flags)
int	getMask()
static JsonGenerator.Feature	valueOf(String name) Returns the enum constant of this type with the specified name.
static JsonGenerator.Feature[]	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

AUTO_CLOSE_TARGET

public static final JsonGenerator.Feature AUTO_CLOSE_TARGET

Feature that determines whether generator will automatically close underlying output target that is NOT owned by the generator. If disabled, calling application has to separately close the underlying OutputStream and Writer instances used to create the generator. If enabled, generator will handle closing, as long as generator itself gets closed: this happens when end-of-input is encountered, or generator is closed by a call to JsonGenerator.close().

Feature is enabled by default.

AUTO_CLOSE_JSON_CONTENT

public static final JsonGenerator.Feature AUTO_CLOSE_JSON_CONTENT

Feature that determines what happens when the generator is closed while there are still unmatched JsonToken.START_ARRAY or JsonToken.START_OBJECT entries in output content. If enabled, such Array(s) and/or Object(s) are automatically closed; if disabled, nothing specific is done.

Feature is enabled by default.

FLUSH_PASSED_TO_STREAM

public static final JsonGenerator.Feature FLUSH_PASSED_TO_STREAM

Feature that specifies that calls to JsonGenerator.flush() will cause matching flush() to underlying OutputStream or Writer; if disabled this will not be done. Main reason to disable this feature is to prevent flushing at generator level, if it is not possible to prevent method being called by other code (like ObjectMapper or third party libraries).

Feature is enabled by default.

QUOTE_FIELD_NAMES

public static final JsonGenerator.Feature QUOTE_FIELD_NAMES

Feature that determines whether JSON Object field names are quoted using double-quotes, as specified by JSON specification or not. Ability to disable quoting was added to support use cases where they are not usually expected, which most commonly occurs when used straight from Javascript.

Feature is enabled by default (since it is required by JSON specification).

QUOTE_NON_NUMERIC_NUMBERS

public static final JsonGenerator.Feature QUOTE_NON_NUMERIC_NUMBERS

Feature that determines whether "exceptional" (not real number) float/double values are output as quoted strings. The values checked are Double.Nan, Double.POSITIVE_INFINITY and Double.NEGATIVE_INIFINTY (and associated Float values). If feature is disabled, these numbers are still output using associated literal values, resulting in non-conformant output.

Feature is enabled by default.

WRITE_NUMBERS_AS_STRINGS

public static final JsonGenerator.Feature WRITE_NUMBERS_AS_STRINGS

Feature that forces all Java numbers to be written as JSON strings. Default state is 'false', meaning that Java numbers are to be serialized using basic numeric serialization (as JSON numbers, integral or floating point). If enabled, all such numeric values are instead written out as JSON Strings.

One use case is to avoid problems with Javascript limitations: since Javascript standard specifies that all number handling should be done using 64-bit IEEE 754 floating point values, result being that some 64-bit integer values can not be accurately represent (as mantissa is only 51 bit wide).

Feature is disabled by default.

WRITE_BIGDECIMAL_AS_PLAIN

public static final JsonGenerator.Feature WRITE_BIGDECIMAL_AS_PLAIN

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

Feature is disabled by default, so default output mode is used; this generally depends on how BigDecimal has been created.

Since:

2.3

ESCAPE_NON_ASCII

public static final JsonGenerator.Feature ESCAPE_NON_ASCII

Feature that specifies that all characters beyond 7-bit ASCII range (i.e. code points of 128 and above) need to be output using format-specific escapes (for JSON, backslash escapes), if format uses escaping mechanisms (which is generally true for textual formats but not for binary formats).

Note that this setting may not necessarily make sense for all data formats (for example, binary formats typically do not use any escaping mechanisms; and some textual formats do not have general-purpose escaping); if so, settings is simply ignored. Put another way, effects of this feature are data-format specific.

Feature is disabled by default.

STRICT_DUPLICATE_DETECTION

public static final JsonGenerator.Feature STRICT_DUPLICATE_DETECTION

Feature that determines whether JsonGenerator will explicitly check that no duplicate JSON Object field names are written. If enabled, generator will check all names within context and report duplicates by throwing a JsonGenerationException; if disabled, no such checking will be done. Assumption in latter case is that caller takes care of not trying to write duplicate names.

Note that enabling this feature will incur performance overhead due to having to store and check additional information.

Feature is disabled by default.

Since:

2.3

IGNORE_UNKNOWN

public static final JsonGenerator.Feature IGNORE_UNKNOWN

Feature that determines what to do if the underlying data format requires knowledge of all properties to output, and if no definition is found for a property that caller tries to write. If enabled, such properties will be quietly ignored; if disabled, a JsonProcessingException will be thrown to indicate the problem. Typically most textual data formats do NOT require schema information (although some do, such as CSV), whereas many binary data formats do require definitions (such as Avro, protobuf), although not all (Smile, CBOR, BSON and MessagePack do not).

Note that support for this feature is implemented by individual data format module, if (and only if) it makes sense for the format in question. For JSON, for example, this feature has no effect as properties need not be pre-defined.

Feature is disabled by default, meaning that if the underlying data format requires knowledge of all properties to output, attempts to write an unknown property will result in a JsonProcessingException

Since:

2.5

Method Detail

values

public static JsonGenerator.Feature[] 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 (JsonGenerator.Feature c : JsonGenerator.Feature.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static JsonGenerator.Feature 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

collectDefaults

public static int collectDefaults()

Method that calculates bit set (flags) of all features that are enabled by default.

enabledByDefault

public boolean enabledByDefault()

enabledIn

public boolean enabledIn(int flags)

Since:

2.3

getMask

public int getMask()