ClassLoaderReference (Java Debug Interface )
Keywords: com.sun.jdi.ClassLoaderReference interface
Date: 2026-04-24

com.sun.jdi

## Interface ClassLoaderReference

- All Superinterfaces:
    Mirror, ObjectReference, Value

      @Exported
      public interface ClassLoaderReference
      extends ObjectReference

  A class loader object from the target VM. A ClassLoaderReference is an `ObjectReference` with additional access to classloader-specific information from the target VM. Instances ClassLoaderReference are obtained through calls to `ReferenceType.classLoader()`
  Since:
    1.3
  See Also:
    `ObjectReference`

- - ### Field Summary

    - ### Fields inherited from interface com.sun.jdi.ObjectReference

      `INVOKE_NONVIRTUAL, INVOKE_SINGLE_THREADED`

  - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method and Description
    --- | ---
    `List<ReferenceType>` | `definedClasses()` Returns a list of all loaded classes that were defined by this class loader.
    `List<ReferenceType>` | `visibleClasses()` Returns a list of all classes for which this class loader has been recorded as the initiating loader in the target VM.

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

      `disableCollection, enableCollection, entryCount, equals, getValue, getValues, hashCode, invokeMethod, isCollected, owningThread, referenceType, referringObjects, setValue, uniqueID, waitingThreads`

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

      `type`

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

      `toString, virtualMachine`

- - ### Method Detail

    - #### definedClasses

          List<ReferenceType> definedClasses()

      Returns a list of all loaded classes that were defined by this class loader. No ordering of this list guaranteed.

      The returned list will include reference types loaded at least to the point of preparation and types (like array) for which preparation is not defined.

      Returns:
        a List of `ReferenceType` objects mirroring types loaded by this class loader. The list has length 0 if no types have been defined by this classloader.

    - #### visibleClasses

          List<ReferenceType> visibleClasses()

      Returns a list of all classes for which this class loader has been recorded as the initiating loader in the target VM. The list contains ReferenceTypes defined directly by this loader (as returned by `definedClasses()`) and any types for which loading was delegated by this class loader to another class loader.

      The visible class list has useful properties with respect to the type namespace. A particular type name will occur at most once in the list. Each field or variable declared with that type name in a class defined by this class loader must be resolved to that single type.

      No ordering of the returned list is guaranteed.

      See The Java™ Virtual Machine Specification, section 5.3 - Creation and Loading for more information on the initiating classloader.

      Note that unlike `definedClasses()` and `VirtualMachine.allClasses()`, some of the returned reference types may not be prepared. Attempts to perform some operations on unprepared reference types (e.g. `fields()`) will throw a `ClassNotPreparedException`. Use `ReferenceType.isPrepared()` to determine if a reference type is prepared.

      Returns:
        a List of `ReferenceType` objects mirroring classes initiated by this class loader. The list has length 0 if no classes are visible to this classloader.

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