# 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`
  Modifier and Type
  Field
  Description
  `static final short`
  `ATTRIBUTE_NODE`
  The node is an `Attr`.
  `static final short`
  `CDATA_SECTION_NODE`
  The node is a `CDATASection`.
  `static final short`
  `COMMENT_NODE`
  The node is a `Comment`.
  `static final short`
  `DOCUMENT_FRAGMENT_NODE`
  The node is a `DocumentFragment`.
  `static final short`
  `DOCUMENT_NODE`
  The node is a `Document`.
  `static final short`
  `DOCUMENT_POSITION_CONTAINED_BY`
  The node is contained by the reference node.
  `static final short`
  `DOCUMENT_POSITION_CONTAINS`
  The node contains the reference node.
  `static final short`
  `DOCUMENT_POSITION_DISCONNECTED`
  The two nodes are disconnected.
  `static final short`
  `DOCUMENT_POSITION_FOLLOWING`
  The node follows the reference node.
  `static final short`
  `DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC`
  The determination of preceding versus following is implementation-specific.
  `static final short`
  `DOCUMENT_POSITION_PRECEDING`
  The second node precedes the reference node.
  `static final short`
  `DOCUMENT_TYPE_NODE`
  The node is a `DocumentType`.
  `static final short`
  `ELEMENT_NODE`
  The node is an `Element`.
  `static final short`
  `ENTITY_NODE`
  The node is an `Entity`.
  `static final short`
  `ENTITY_REFERENCE_NODE`
  The node is an `EntityReference`.
  `static final short`
  `NOTATION_NODE`
  The node is a `Notation`.
  `static final short`
  `PROCESSING_INSTRUCTION_NODE`
  The node is a `ProcessingInstruction`.
  `static final short`
  `TEXT_NODE`
  The node is a `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`
  Modifier and Type
  Method
  Description
  `Node`
  `appendChild(Node newChild)`
  Adds the node `newChild` to the end of the list of children of this node.
  `Node`
  `cloneNode(boolean deep)`
  Returns a duplicate of this node, i.e., serves as a generic copy constructor for nodes.
  `short`
  `compareDocumentPosition(Node other)`
  Compares the reference node, i.e. the node on which this method is being called, with a node, i.e. the one passed as a parameter, with regard to their position in the document and according to the document order.
  `NamedNodeMap`
  `getAttributes()`
  A `NamedNodeMap` containing the attributes of this node (if it is an `Element`) or `null` otherwise.
  `String`
  `getBaseURI()`
  The absolute base URI of this node or `null` if the implementation wasn't able to obtain an absolute URI.
  `NodeList`
  `getChildNodes()`
  A `NodeList` that contains all children of this node.
  `Object`
  `getFeature(String feature, String version)`
  This method returns a specialized object which implements the specialized APIs of the specified feature and version, as specified in .
  `Node`
  `getFirstChild()`
  The first child of this node.
  `Node`
  `getLastChild()`
  The last child of this node.
  `String`
  `getLocalName()`
  Returns the local part of the qualified name of this node.
  `String`
  `getNamespaceURI()`
  The namespace URI of this node, or `null` if it is unspecified (see ).
  `Node`
  `getNextSibling()`
  The node immediately following this node.
  `String`
  `getNodeName()`
  The name of this node, depending on its type; see the table above.
  `short`
  `getNodeType()`
  A code representing the type of the underlying object, as defined above.
  `String`
  `getNodeValue()`
  The value of this node, depending on its type; see the table above.
  `Document`
  `getOwnerDocument()`
  The `Document` object associated with this node.
  `Node`
  `getParentNode()`
  The parent of this node.
  `String`
  `getPrefix()`
  The namespace prefix of this node, or `null` if it is unspecified.
  `Node`
  `getPreviousSibling()`
  The node immediately preceding this node.
  `String`
  `getTextContent()`
  This attribute returns the text content of this node and its descendants.
  `Object`
  `getUserData(String key)`
  Retrieves the object associated to a key on a this node.
  `boolean`
  `hasAttributes()`
  Returns whether this node (if it is an element) has any attributes.
  `boolean`
  `hasChildNodes()`
  Returns whether this node has any children.
  `Node`
  `insertBefore(Node newChild, Node refChild)`
  Inserts the node `newChild` before the existing child node `refChild`.
  `boolean`
  `isDefaultNamespace(String namespaceURI)`
  This method checks if the specified `namespaceURI` is the default namespace or not.
  `boolean`
  `isEqualNode(Node arg)`
  Tests whether two nodes are equal.
  `boolean`
  `isSameNode(Node other)`
  Returns whether this node is the same node as the given one.
  `boolean`
  `isSupported(String feature, String version)`
  Tests whether the DOM implementation implements a specific feature and that feature is supported by this node, as specified in .
  `String`
  `lookupNamespaceURI(String prefix)`
  Look up the namespace URI associated to the given prefix, starting from this node.
  `String`
  `lookupPrefix(String namespaceURI)`
  Look up the prefix associated to the given namespace URI, starting from this node.
  `void`
  `normalize()`
  Puts all `Text` nodes in the full depth of the sub-tree underneath this `Node`, including attribute nodes, into a "normal" form where only structure (e.g., elements, comments, processing instructions, CDATA sections, and entity references) separates `Text` nodes, i.e., there are neither adjacent `Text` nodes nor empty `Text` nodes.
  `Node`
  `removeChild(Node oldChild)`
  Removes the child node indicated by `oldChild` from the list of children, and returns it.
  `Node`
  `replaceChild(Node newChild, Node oldChild)`
  Replaces the child node `oldChild` with `newChild` in the list of children, and returns the `oldChild` node.
  `void`
  `setNodeValue(String nodeValue)`
  The value of this node, depending on its type; see the table above.
  `void`
  `setPrefix(String prefix)`
  The namespace prefix of this node, or `null` if it is unspecified.
  `void`
  `setTextContent(String textContent)`
  This attribute returns the text content of this node and its descendants.
  `Object`
  `setUserData(String key, Object data, UserDataHandler handler)`
  Associate an object to a key on this node.

- ## 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