# Interface Entity

All Superinterfaces:
  `Node`

public interface Entity extends Node
This interface represents a known entity, either parsed or unparsed, in an XML document. Note that this models the entity itself not the entity declaration.

The `nodeName` attribute that is inherited from `Node` contains the name of the entity.

An XML processor may choose to completely expand entities before the structure model is passed to the DOM; in this case there will be no `EntityReference` nodes in the document tree.

XML does not mandate that a non-validating XML processor read and process entity declarations made in the external subset or declared in parameter entities. This means that parsed entities declared in the external subset need not be expanded by some classes of applications, and that the replacement text of the entity may not be available. When the replacement text is available, the corresponding `Entity` node's child list represents the structure of that replacement value. Otherwise, the child list is empty.

DOM Level 3 does not support editing `Entity` nodes; if a user wants to make changes to the contents of an `Entity`, every related `EntityReference` node has to be replaced in the structure model by a clone of the `Entity`'s contents, and then the desired changes must be made to each of those clones instead. `Entity` nodes and all their descendants are readonly.

An `Entity` node does not have any parent.

Note: If the entity contains an unbound namespace prefix, the `namespaceURI` of the corresponding node in the `Entity` node subtree is `null`. The same is true for `EntityReference` nodes that refer to this entity, when they are created using the `createEntityReference` method of the `Document` interface.

See also the Document Object Model (DOM) Level 3 Core Specification.

Since:
  1.4, DOM Level 2

- ## Field Summary

  ### Fields declared in interface Node

  `ATTRIBUTE_NODE, CDATA_SECTION_NODE, COMMENT_NODE, DOCUMENT_FRAGMENT_NODE, DOCUMENT_NODE, DOCUMENT_POSITION_CONTAINED_BY, DOCUMENT_POSITION_CONTAINS, DOCUMENT_POSITION_DISCONNECTED, DOCUMENT_POSITION_FOLLOWING, DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC, DOCUMENT_POSITION_PRECEDING, DOCUMENT_TYPE_NODE, ELEMENT_NODE, ENTITY_NODE, ENTITY_REFERENCE_NODE, NOTATION_NODE, PROCESSING_INSTRUCTION_NODE, TEXT_NODE`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `String`
  `getInputEncoding()`
  An attribute specifying the encoding used for this entity at the time of parsing, when it is an external parsed entity.
  `String`
  `getNotationName()`
  For unparsed entities, the name of the notation for the entity.
  `String`
  `getPublicId()`
  The public identifier associated with the entity if specified, and `null` otherwise.
  `String`
  `getSystemId()`
  The system identifier associated with the entity if specified, and `null` otherwise.
  `String`
  `getXmlEncoding()`
  An attribute specifying, as part of the text declaration, the encoding of this entity, when it is an external parsed entity.
  `String`
  `getXmlVersion()`
  An attribute specifying, as part of the text declaration, the version number of this entity, when it is an external parsed entity.

  ### Methods declared in interface Node

  `appendChild, cloneNode, compareDocumentPosition, getAttributes, getBaseURI, getChildNodes, getFeature, getFirstChild, getLastChild, getLocalName, getNamespaceURI, getNextSibling, getNodeName, getNodeType, getNodeValue, getOwnerDocument, getParentNode, getPrefix, getPreviousSibling, getTextContent, getUserData, hasAttributes, hasChildNodes, insertBefore, isDefaultNamespace, isEqualNode, isSameNode, isSupported, lookupNamespaceURI, lookupPrefix, normalize, removeChild, replaceChild, setNodeValue, setPrefix, setTextContent, setUserData`

- ## Method Details

  - ### getPublicId

    String getPublicId()
    The public identifier associated with the entity if specified, and `null` otherwise.

  - ### getSystemId

    String getSystemId()
    The system identifier associated with the entity if specified, and `null` otherwise. This may be an absolute URI or not.

  - ### getNotationName

    String getNotationName()
    For unparsed entities, the name of the notation for the entity. For parsed entities, this is `null`.

  - ### getInputEncoding

    String getInputEncoding()
    An attribute specifying the encoding used for this entity at the time of parsing, when it is an external parsed entity. This is `null` if it an entity from the internal subset or if it is not known.
    Since:
      1.5, DOM Level 3

  - ### getXmlEncoding

    String getXmlEncoding()
    An attribute specifying, as part of the text declaration, the encoding of this entity, when it is an external parsed entity. This is `null` otherwise.
    Since:
      1.5, DOM Level 3

  - ### getXmlVersion

    String getXmlVersion()
    An attribute specifying, as part of the text declaration, the version number of this entity, when it is an external parsed entity. This is `null` otherwise.
    Since:
      1.5, DOM Level 3