Package net.sf.saxon.om

Interface NodeName

All Superinterfaces:
IdentityComparable
All Known Implementing Classes:
CodedName, FingerprintedQName, NameOfNode, NoNamespaceName
public interface NodeName extends IdentityComparable
This interface represents a node name. Actually it represents any QName, but it is intended for use as an element or attribute name. Various implementations are available.

An important requirement of an implementation of this interface is that the hashCode() and equals() methods are implemented correctly, so that any two node names compare equal if and only if the local name and namespace URI parts are equal under Unicode codepoint comparison. To ensure this, the hashCode must be computed using an algorithm equivalent to that used by the implementation class FingerprintedQName

This class is used to carry name information for elements and attributes on the Receiver pipeline. An advantage of this is that NodeName can include a fingerprint where this is available, but the fingerprint does not need to be computed if it is not needed. For example, names of nodes constructed by an XSLT stylesheet and sent down an output pipeline to a Serializer will generally not have fingerprints.

Equality comparisons between NodeNames work reasonably well: the comparison can use the fingerprints if available, or the QNames otherwise. However, computing hashCodes is inefficient; it is not possible to take advantage of the fingerprints, because they are not always there. Therefore, using NodeName objects in structures such as maps and sets is generally a bad idea: it's better to use either the StructuredQName or the fingerprint as the key.

  • Method Details

    • getPrefix

      String getPrefix()
      Get the prefix of the QName.
      Returns:
      the prefix. Returns the empty string if the name is unprefixed.

    • getNamespaceUri

      NamespaceUri getNamespaceUri()
      Get the namespace URI of the node name.
      Returns:
      the URI. Returns NamespaceUri.NULL for nodes that are not in any namespace

    • getURI

      default String getURI()
      Get the namespace URI of the QName, as a string.

      This method is retained for backwards compatibility, but getNamespaceUri() is preferred.

      Returns:
      the namespace URI. Returns the zero-length string for nodes that are not in any namespace

    • getLocalPart

      String getLocalPart()
      Get the local part of the QName
      Returns:
      the local part of the QName

    • getDisplayName

      String getDisplayName()
      Get the display name, that is the lexical QName in the form [prefix:]local-part
      Returns:
      the lexical QName

    • getStructuredQName

      StructuredQName getStructuredQName()
      Get the name in the form of a StructuredQName
      Returns:
      the name in the form of a StructuredQName

    • hasURI

      boolean hasURI(NamespaceUri ns)
      Test whether this name is in a given namespace
      Parameters:
      ns - the namespace to be tested against
      Returns:
      true if the name is in the specified namespace

    • getNamespaceBinding

      NamespaceBinding getNamespaceBinding()
      Get a NamespaceBinding whose (prefix, uri) pair are the prefix and URI of this node name
      Returns:
      the corresponding NamespaceBinding

    • hasFingerprint

      boolean hasFingerprint()
      Ask whether this node name representation has a known fingerprint
      Returns:
      true if the method getFingerprint() will return a result other than -1

    • getFingerprint

      int getFingerprint()
      Get the fingerprint of this name if known. This method should not do any work to allocate a fingerprint if none is already available
      Returns:
      the fingerprint if known; otherwise -1

    • obtainFingerprint

      int obtainFingerprint(NamePool namePool)
      Get the fingerprint of this name, allocating a new code from the namepool if necessary
      Parameters:
      namePool - the NamePool used to allocate the name
      Returns:
      a fingerprint for this name, newly allocated if necessary