# Interface ConstantDynamicEntry

All Superinterfaces:
  `DynamicConstantPoolEntry`, `LoadableConstantEntry`, `PoolEntry`

public sealed interface ConstantDynamicEntry extends DynamicConstantPoolEntry, LoadableConstantEntry
Models a `CONSTANT_Dynamic_info` structure, representing a dynamically-computed constant, in the constant pool of a `class` file.

The use of a `ConstantDynamicEntry` is modeled by a `DynamicConstantDesc`. Conversions are through `asSymbol()` and `ConstantPoolBuilder.constantDynamicEntry(DynamicConstantDesc)`.

A dynamic constant entry is composite:

    ConstantDynamicEntry(
        BootstrapMethodEntry bootstrap,
        NameAndTypeEntry nameAndType
    )

where `nameAndType.type()` is a field descriptor string.

API Note:
  A dynamically-computed constant is frequently called a dynamic constant, or a condy, from the abbreviation of "constant dynamic".
See Java Virtual Machine Specification:
  4.4.10 The `CONSTANT_Dynamic_info` and `CONSTANT_InvokeDynamic_info` Structures
Since:
  24
See Also:
  - `ConstantPoolBuilder::constantDynamicEntry`
  - `DynamicConstantDesc`
  - Dynamically-computed constants

- ## Field Summary

  ### Fields declared in interface java.lang.classfile.constantpool.PoolEntry

  `TAG_CLASS, TAG_DOUBLE, TAG_DYNAMIC, TAG_FIELDREF, TAG_FLOAT, TAG_INTEGER, TAG_INTERFACE_METHODREF, TAG_INVOKE_DYNAMIC, TAG_LONG, TAG_METHOD_HANDLE, TAG_METHOD_TYPE, TAG_METHODREF, TAG_MODULE, TAG_NAME_AND_TYPE, TAG_PACKAGE, TAG_STRING, TAG_UTF8`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `default DynamicConstantDesc<?>`
  `asSymbol()`
  Returns a symbolic descriptor for this dynamically-computed constant.
  `default ConstantDesc`
  `constantValue()`
  Returns a symbolic descriptor of this constant.
  `default TypeKind`
  `typeKind()`
  Returns the data type of this constant.
  `default ClassDesc`
  `typeSymbol()`
  Returns a symbolic descriptor for the field type of this dynamically-computed constant.

  ### Methods declared in interface java.lang.classfile.constantpool.DynamicConstantPoolEntry

  `bootstrap, bootstrapMethodIndex, name, nameAndType, type`

  ### Methods declared in interface java.lang.classfile.constantpool.PoolEntry

  `constantPool, index, tag, width`

- ## Method Details

  - ### typeSymbol

    default ClassDesc typeSymbol()
    Returns a symbolic descriptor for the field type of this dynamically-computed constant.
    Returns:
      a symbolic descriptor for the field type of this dynamically-computed constant

  - ### constantValue

    default ConstantDesc constantValue()
    Returns a symbolic descriptor of this constant.

    This is equivalent to `asSymbol()`.

    Specified by:
      `constantValue` in interface `LoadableConstantEntry`
    Returns:
      a symbolic descriptor of this constant
    See Also:
      - `ConstantPoolBuilder.loadableConstantEntry(ConstantDesc)`

  - ### asSymbol

    default DynamicConstantDesc<?> asSymbol()
    Returns a symbolic descriptor for this dynamically-computed constant.
    Returns:
      a symbolic descriptor for this dynamically-computed constant
    See Also:
      - `ConstantPoolBuilder::constantDynamicEntry(DynamicConstantDesc)`

  - ### typeKind

    default TypeKind typeKind()
    Returns the data type of this constant.

    If the data type is of category 2, this constant must be loaded with `ldc2_w`; otherwise, the data type is of category 1, and this constant must be loaded with `ldc` or `ldc_w`.

    Specified by:
      `typeKind` in interface `LoadableConstantEntry`
    API Note:
      The data type of a dynamically-computed constant depends on its descriptor, while the data type of all other constants can be determined by their constant type.
    Returns:
      the data type of this constant