# Package org.apache.tapestry5.internal.util

[INTERNAL USE ONLY] various utility classes; API subject to change.

- Class Summary
  Class | Description
  --- | ---
  AutofocusValidationDecorator | Used by `Form` to determine which fields will be focused and a what priority.
  Base64InputStream | An extension of `ByteArrayInputStream` that is initialized from a Base64 input stream (rather than from a byte array).
  Base64OutputStream | An extension of `ByteArrayOutputStream` that allows the final byte array to be converted to a Base64 string.
  CaptureResultCallback<T> | Implementation of `ComponentEventCallback` that simply captures the result value.
  Holder<T> | An object that holds some type of other object.
  LocaleUtils | Contains code borrowed from commons-lang.
  MacOutputStream | An output stream that wraps around a `Mac` (message authentication code algorithm).
  MessageCatalogResource |
  NamedSet<T> | Simple, thread-safe associative array that relates a name to a value.
  NotificationEventCallback | A `ComponentEventCallback` used for notification events.
  PrintOutCollector | Utility for collecting the output of a `PrintWriter`.
  RecomputableSupport | A utility class for managing a cacheable result that can be recomputed when needed.
  RenderableAsBlock | Allows any `Renderable` object to act as a `Block`.
  SelectModelRenderer |
  StringRenderable | Renders a string using `MarkupWriter.write(String)`.
  TeeOutputStream | An output stream that acts like a "tee", copying all provided bytes to two output streams.
  ValidationDecoratorWrapper | Implementation of `ValidationDecorator` that delegates all method invocations.
  VirtualResource | Base class for virtual resources: resources that are not simply mapped to stored files, but are assembled, as necessary, on the fly.