Type (Java Debug Interface )
Keywords: com.sun.jdi.Type interface
Date: 2026-03-16

com.sun.jdi

## Interface Type

- All Superinterfaces:
    Mirror
  All Known Subinterfaces:
    ArrayType, BooleanType, ByteType, CharType, ClassType, DoubleType, FloatType, IntegerType, InterfaceType, LongType, PrimitiveType, ReferenceType, ShortType, VoidType

      @Exported
      public interface Type
      extends Mirror

  The mirror for a type in the target VM. This interface is the root of a type hierarchy encompassing primitive types and reference types.

  A Type may be used to represent a run-time type:

  > `Value`.type()

  or a compile-time type:

  > `Field.type()`
  > `Method.returnType()`
  > `Method.argumentTypes()`
  > `LocalVariable.type()`
  > `ArrayType.componentType()`

  The following table illustrates which subinterfaces of Type are used to mirror types in the target VM --

  Subinterfaces of `PrimitiveType`
  Type declared in target as | Is mirrored as an instance of
  --- | ---
  `boolean` | `BooleanType`
  `byte` | `ByteType`
  `char` | `CharType`
  `double` | `DoubleType`
  `float` | `FloatType`
  `int` | `IntegerType`
  `long` | `LongType`
  `short` | `ShortType`
  `void` | `VoidType`
  Subinterfaces of `ReferenceType`
  Type declared in target as | For example | Is mirrored as an instance of
  a class | `Date` | `ClassType`
  an interface | `Runnable` | `InterfaceType`
  an array |  | `ArrayType`
  an array | `int[]` | `ArrayType` whose `componentType()` is `IntegerType`
  an array | `Date[]` | `ArrayType` whose `componentType()` is `ClassType`
  an array | `Runnable[]` | `ArrayType` whose `componentType()` is `InterfaceType`

  Since:
    1.3
  See Also:
    `Subinterface PrimitiveType`, `Subinterface ReferenceType`, `Value - for relationship between Type and Value`, `Field.type() - for usage examples`

- - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method and Description
    --- | ---
    `String` | `name()`
    `String` | `signature()` Returns the JNI-style signature for this type.

    - ### Methods inherited from interface com.sun.jdi.Mirror

      `toString, virtualMachine`

- - ### Method Detail

    - #### signature

          String signature()

      Returns the JNI-style signature for this type.

      For primitive classes the returned signature is the signature of the corresponding primitive type; for example, "I" is returned as the signature of the class represented by `Integer.TYPE`.

      Returns:
        the string containing the type signature.
      See Also:
        Type Signatures

    - #### name

          String name()

      Returns:
        a text representation of this type.

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