com.fasterxml.jackson.core

## Enum StreamReadFeature

- java.lang.Object
- - java.lang.Enum<StreamReadFeature>
  - - com.fasterxml.jackson.core.StreamReadFeature

All Implemented Interfaces:
  JacksonFeature, Serializable, Comparable<StreamReadFeature>

    public enum StreamReadFeature
    extends Enum<StreamReadFeature>
    implements JacksonFeature

Token reader (parser) features not-specific to any particular format backend. Eventual replacement for non-JSON-specific `JsonParser.Feature`s.

Since:
  2.10

### Enum Constant Summary

Enum Constants
Enum Constant and Description
`AUTO_CLOSE_SOURCE` Feature that determines whether parser will automatically close underlying input source that is NOT owned by the parser.
`IGNORE_UNDEFINED` Feature that determines what to do if the underlying data format requires knowledge of all properties to decode (usually via a Schema), and if no definition is found for a property that input content contains.
`INCLUDE_SOURCE_IN_LOCATION` Feature that determines whether `JsonLocation` instances should be constructed with reference to source or not.
`STRICT_DUPLICATE_DETECTION` Feature that determines whether `JsonParser` will explicitly check that no duplicate JSON Object field names are encountered.
`USE_FAST_DOUBLE_PARSER` Feature that determines whether we use the built-in `Double.parseDouble(String)` code to parse doubles or if we use `com.fasterxml.jackson.core.io.doubleparser` instead.

### Method Summary

All Methods Static Methods Instance Methods Concrete Methods
`static int` `collectDefaults()` Method that calculates bit set (flags) of all features that are enabled by default.
`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; must be a single bit, that is of form `1 << N`.
`JsonParser.Feature` `mappedFeature()`
`static StreamReadFeature` `valueOf(String name)` Returns the enum constant of this type with the specified name.
`static StreamReadFeature[]` `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_SOURCE

    public static final StreamReadFeature AUTO_CLOSE_SOURCE

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

Feature is enabled by default.

#### STRICT_DUPLICATE_DETECTION

    public static final StreamReadFeature STRICT_DUPLICATE_DETECTION

Feature that determines whether `JsonParser` will explicitly check that no duplicate JSON Object field names are encountered. If enabled, parser will check all names within context and report duplicates by throwing a `JsonParseException`; if disabled, parser will not do such checking. Assumption in latter case is that caller takes care of handling duplicates at a higher level: data-binding, for example, has features to specify detection to be done there.

Note that enabling this feature will incur performance overhead due to having to store and check additional information: this typically adds 20-30% to execution time for basic parsing.

#### IGNORE_UNDEFINED

    public static final StreamReadFeature IGNORE_UNDEFINED

Feature that determines what to do if the underlying data format requires knowledge of all properties to decode (usually via a Schema), and if no definition is found for a property that input content contains. 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). Further note that some formats that do require schema information will not be able to ignore undefined properties: for example, Avro is fully positional and there is no possibility of undefined data. This leaves formats like Protobuf that have identifiers that may or may not map; and as such Protobuf format does make use of this feature.

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 read an unknown property will result in a `JsonProcessingException`

#### INCLUDE_SOURCE_IN_LOCATION

    public static final StreamReadFeature INCLUDE_SOURCE_IN_LOCATION

Feature that determines whether `JsonLocation` instances should be constructed with reference to source or not. If source reference is included, its type and contents are included when `toString()` method is called (most notably when printing out parse exception with that location information). If feature is disabled, no source reference is passed and source is only indicated as "UNKNOWN".

Most common reason for disabling this feature is to avoid leaking internal information; this may be done for security reasons. Note that even if source reference is included, only parts of contents are usually printed, and not the whole contents. Further, many source reference types can not necessarily access contents (like streams), so only type is indicated, not contents.

Feature is enabled by default, meaning that "source reference" information is passed and some or all of the source content may be included in `JsonLocation` information constructed either when requested explicitly, or when needed for an exception.

#### USE_FAST_DOUBLE_PARSER

    public static final StreamReadFeature USE_FAST_DOUBLE_PARSER

Feature that determines whether we use the built-in `Double.parseDouble(String)` code to parse doubles or if we use `com.fasterxml.jackson.core.io.doubleparser` instead.

This setting is disabled by default.

Since:
  2.14

### Method Detail

#### values

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

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

#### valueOf

    public static StreamReadFeature 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.

Returns:
  Bit mask of all features that are enabled by default

#### enabledByDefault

    public boolean enabledByDefault()

Description copied from interface: `JacksonFeature`
Accessor for checking whether this feature is enabled by default.

Specified by:
  `enabledByDefault` in interface `JacksonFeature`
Returns:
  Whether this instance is enabled by default or not

#### enabledIn

    public boolean enabledIn(int flags)

Description copied from interface: `JacksonFeature`
Convenience method for checking whether feature is enabled in given bitmask.

Specified by:
  `enabledIn` in interface `JacksonFeature`
Parameters:
  `flags` - Bit field that contains a set of enabled features of this type
Returns:
  True if this feature is enabled in passed bit field

#### getMask

    public int getMask()

Description copied from interface: `JacksonFeature`
Returns bit mask for this feature instance; must be a single bit, that is of form `1 << N`.

Specified by:
  `getMask` in interface `JacksonFeature`
Returns:
  Bit mask of this feature

#### mappedFeature

    public JsonParser.Feature mappedFeature()