Enum StreamReadCapability

Enum Constant Details

• DUPLICATE_PROPERTIES

  public static final StreamReadCapability DUPLICATE_PROPERTIES

  Capability that indicates that data format can expose multiple properties with same name ("duplicates") within one Object context. This is usually not enabled, except for formats like xml that have content model that does not map cleanly to JSON-based token stream.

  Capability may be used for allowing secondary mapping of such duplicates in case of using Tree Model (see TreeNode), or "untyped" databinding (mapping content as generic Object).

  Capability is currently only enabled for XML format backend.

• SCALARS_AS_OBJECTS

  public static final StreamReadCapability SCALARS_AS_OBJECTS

  Capability that indicates that data format may in some cases expose Scalar values (whether typed or untyped) as Object values. There are additional access methods at databind level: this capability may be used to decide whether to attempt to use such methods especially in potentially ambiguous cases.

  Capability is currently only enabled for XML format backend.

• UNTYPED_SCALARS

  public static final StreamReadCapability UNTYPED_SCALARS

  Capability that indicates that data format only exposed "untyped" scalars: that is, instead of Number, Boolean and String types all scalar values are reported as text (JsonToken.VALUE_STRING) unless some sort of coercion is implied by caller.

  This capability is true for many textual formats like CSV, Properties and XML.

• EXACT_FLOATS

  public static final StreamReadCapability EXACT_FLOATS

  Capability that indicates whether data format supports reporting of accurate floating point values (with respect to reported numeric type, JsonParser.NumberType.DOUBLE) or not. This usually depends on whether format stores such values natively (as IEEE binary FP formats for java.lang.Float and java.lang.Double; using some other value preserving presentation for java.math.BigDecimal) or not: most binary formats do, and most textual formats do not (at least for Float and Double, specifically).

  In case of JSON numbers (as well as for most if not all textual formats), all floating-point numbers are represented simply by decimal (10-base) textual representation and can only be represented accurately using BigDecimal. But for performance reasons they may be (depending on settings) be exposed as Doubles (that is, JsonParser.NumberType.DOUBLE). Note that methods like JsonParser.getNumberValueExact(), JsonParser.getValueAsString() and JsonParser.getDecimalValue() report values without precision loss.

  The main intended use case is to let non-Jackson code to handle cases where exact accuracy is necessary in a way that handling does not incur unnecessary conversions across different formats: for example, when reading binary format, simple access is essentially guaranteed to expose value exactly as encoded by the format (as float, double or BigDecimal), whereas for textual formats like JSON it is necessary to access value explicitly as BigDecimal using JsonParser#getDecimalValue.

  Capability is false for text formats like JSON, but true for binary formats like Smile, MessagePack, etc., where type is precisely and inexpensively indicated by format.

  Since:

  2.14