# Package jakarta.servlet.jsp.tagext

package jakarta.servlet.jsp.tagext
Classes and interfaces for the definition of JavaServer Pages Tag Libraries.

The JavaServer Pages(tm) (JSP) 2.0 specification provides a portable mechanism for the description of tag libraries.

A JSP tag library contains

- A Tag Library Descriptor
- A number of Tag Files or Tag handler classes defining request-time behavior
- Additional classes and resources used at runtime
- Possibly some additional classes to provide extra translation information

The JSP 2.0 specification and the reference implementation both contain simple and moderately complex examples of actions defined using this mechanism. These are available at JSP's web site, at http://java.sun.com/products/jsp. Some readers may want to consult those to get a quick feel for how the mechanisms work together.

- Related Packages
  Package
  Description
  jakarta.servlet.jsp
  Classes and interfaces for the Core JSP 2.0 API.
  jakarta.servlet.jsp.el
  Classes and interfaces for the JSP 2.0 Expression Language API.
- Class
  Description
  BodyContent
  An encapsulation of the evaluation of the body of an action so it is available to a tag handler.
  BodyTag
  The BodyTag interface extends IterationTag by defining additional methods that let a tag handler manipulate the content of evaluating its body.
  BodyTagSupport
  A base class for defining tag handlers implementing BodyTag.
  DynamicAttributes
  For a tag to declare that it accepts dynamic attributes, it must implement this interface.
  FunctionInfo
  Information for a function in a Tag Library.
  IterationTag
  The IterationTag interface extends Tag by defining one additional method that controls the reevaluation of its body.
  JspFragment
  Encapsulates a portion of JSP code in an object that can be invoked as many times as needed.
  JspIdConsumer
  Interface that allows tag handlers to be provided with a unique (within the scope of the web application) ID.
  JspTag
  Serves as a base class for Tag and SimpleTag.
  PageData
  Translation-time information on a JSP page.
  SimpleTag
  Interface for defining Simple Tag Handlers.
  SimpleTagSupport
  A base class for defining tag handlers implementing SimpleTag.
  Tag
  The interface of a classic tag handler that does not want to manipulate its body.
  TagAdapter
  Wraps any SimpleTag and exposes it using a Tag interface.
  TagAttributeInfo
  Information on the attributes of a Tag, available at translation time.
  TagData
  The (translation-time only) attribute/value information for a tag instance.
  TagExtraInfo
  Optional class provided by the tag library author to describe additional translation-time information not described in the TLD.
  TagFileInfo
  Tag information for a tag file in a Tag Library; This class is instantiated from the Tag Library Descriptor file (TLD) and is available only at translation time.
  TagInfo
  Tag information for a tag in a Tag Library; This class is instantiated from the Tag Library Descriptor file (TLD) and is available only at translation time.
  TagLibraryInfo
  Translation-time information associated with a taglib directive, and its underlying TLD file.
  TagLibraryValidator
  Translation-time validator class for a JSP page.
  TagSupport
  A base class for defining new tag handlers implementing Tag.
  TagVariableInfo
  Variable information for a tag in a Tag Library; This class is instantiated from the Tag Library Descriptor file (TLD) and is available only at translation time.
  TryCatchFinally
  The auxiliary interface of a Tag, IterationTag or BodyTag tag handler that wants additional hooks for managing resources.
  ValidationMessage
  A validation message from either TagLibraryValidator or TagExtraInfo.
  VariableInfo
  Information on the scripting variables that are created/modified by a tag (at run-time).