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/OpenJDK 21

Interface Value

All Superinterfaces:
Mirror
All Known Subinterfaces:
ArrayReference, BooleanValue, ByteValue, CharValue, ClassLoaderReference, ClassObjectReference, DoubleValue, FloatValue, IntegerValue, LongValue, ModuleReference, ObjectReference, PrimitiveValue, ShortValue, StringReference, ThreadGroupReference, ThreadReference, VoidValue
public interface Value extends Mirror
The mirror for a value in the target VM. This interface is the root of a value hierarchy encompassing primitive values and object values.

Some examples of where values may be accessed:

ObjectReference.getValue(Field) - value of a field
StackFrame.getValue(LocalVariable) - value of a variable
VirtualMachine.mirrorOf(double) - created in the target VM by the JDI client
ModificationWatchpointEvent.valueToBe() - returned with an event

The following tables illustrate which subinterfaces of Value are used to mirror values in the target VM --

Subinterfaces of PrimitiveValue
Kind of value For example -
expression in target
Is mirrored as an
instance of
Type of value
Value.type()
a boolean true BooleanValue BooleanType
a byte (byte)4 ByteValue ByteType
a char 'a' CharValue CharType
a double 3.1415926 DoubleValue DoubleType
a float 2.5f FloatValue FloatType
an int 22 IntegerValue IntegerType
a long 1024L LongValue LongType
a short (short)12 ShortValue ShortType
a void VoidValue VoidType
Subinterfaces of ObjectReference
Kind of value For example -
expression in target
Is mirrored as an
instance of
Type of value
Value.type()
a class instance this ObjectReference ClassType
an array new int[5] ArrayReference ArrayType
a string "hello" StringReference ClassType
a thread Thread.currentThread() ThreadReference ClassType
a thread group Thread.currentThread()
.getThreadGroup()
ThreadGroupReference ClassType
a java.lang.Class
instance
this.getClass() ClassObjectReference ClassType
a class loader this.getClass()
.getClassLoader()
ClassLoaderReference ClassType
Other values
Kind of value For example -
expression in target
Is mirrored as Type of value
null null null n/a
Since:
1.3

Method Summary

Modifier and Type Method Description
Type type()
Returns the run-time type of this value.

Methods declared in interface com.sun.jdi.Mirror

toString, virtualMachine

Method Details

type

Type type()
Returns the run-time type of this value.
Returns:
a Type which mirrors the value's type in the target VM.
See Also:

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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
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https://docs.oracle.com/en/java/javase/21/docs/api/jdk.jdi/com/sun/jdi/Value.html