Module java.xml
Package javax.xml.namespace

Interface NamespaceContext


  • public interface NamespaceContext
    Interface for read only XML Namespace context processing.

    An XML Namespace has the properties:

    • Namespace URI: Namespace name expressed as a URI to which the prefix is bound
    • prefix: syntactically, this is the part of the attribute name following the XMLConstants.XMLNS_ATTRIBUTE ("xmlns") in the Namespace declaration

    example: <element xmlns:prefix="http://Namespace-name-URI">

    All get*(*) methods operate in the current scope for Namespace URI and prefix resolution.

    Note that a Namespace URI can be bound to multiple prefixes in the current scope. This can occur when multiple XMLConstants.XMLNS_ATTRIBUTE ("xmlns") Namespace declarations occur in the same Start-Tag and refer to the same Namespace URI. e.g.

     
 <element xmlns:prefix1="http://Namespace-name-URI"
          xmlns:prefix2="http://Namespace-name-URI">
    This can also occur when the same Namespace URI is used in multiple XMLConstants.XMLNS_ATTRIBUTE ("xmlns") Namespace declarations in the logical parent element hierarchy. e.g.
     
 <parent xmlns:prefix1="http://Namespace-name-URI">
   <child xmlns:prefix2="http://Namespace-name-URI">
     ...
   </child>
 </parent>

    A prefix can only be bound to a single Namespace URI in the current scope.

    Since:
    1.5
    See Also:
    javax.xml.XMLConstants for declarations of common XML values, XML Schema Part2: Datatypes, Namespaces in XML, Namespaces in XML Errata

    • Method Detail

      • getNamespaceURI

        String getNamespaceURI​(String prefix)
        Get Namespace URI bound to a prefix in the current scope.

        When requesting a Namespace URI by prefix, the following table describes the returned Namespace URI value for all possible prefix values:

        Return value for specified prefixes
        prefix parameter Namespace URI return value
        DEFAULT_NS_PREFIX ("") default Namespace URI in the current scope or XMLConstants.NULL_NS_URI("") when there is no default Namespace URI in the current scope
        bound prefix Namespace URI bound to prefix in current scope
        unbound prefix XMLConstants.NULL_NS_URI("")
        XMLConstants.XML_NS_PREFIX ("xml") XMLConstants.XML_NS_URI ("http://www.w3.org/XML/1998/namespace")
        XMLConstants.XMLNS_ATTRIBUTE ("xmlns") XMLConstants.XMLNS_ATTRIBUTE_NS_URI ("http://www.w3.org/2000/xmlns/")
        null IllegalArgumentException is thrown
        Parameters:
        prefix - prefix to look up
        Returns:
        Namespace URI bound to prefix in the current scope
        Throws:
        IllegalArgumentException - When prefix is null

      • getPrefix

        String getPrefix​(String namespaceURI)
        Get prefix bound to Namespace URI in the current scope.

        To get all prefixes bound to a Namespace URI in the current scope, use getPrefixes(String namespaceURI).

        When requesting a prefix by Namespace URI, the following table describes the returned prefix value for all Namespace URI values:

        Return value for specified Namespace URIs
        Namespace URI parameter prefix value returned
        <default Namespace URI> XMLConstants.DEFAULT_NS_PREFIX ("")
        bound Namespace URI prefix bound to Namespace URI in the current scope, if multiple prefixes are bound to the Namespace URI in the current scope, a single arbitrary prefix, whose choice is implementation dependent, is returned
        unbound Namespace URI null
        XMLConstants.XML_NS_URI ("http://www.w3.org/XML/1998/namespace") XMLConstants.XML_NS_PREFIX ("xml")
        XMLConstants.XMLNS_ATTRIBUTE_NS_URI ("http://www.w3.org/2000/xmlns/") XMLConstants.XMLNS_ATTRIBUTE ("xmlns")
        null IllegalArgumentException is thrown
        Parameters:
        namespaceURI - URI of Namespace to lookup
        Returns:
        prefix bound to Namespace URI in current context
        Throws:
        IllegalArgumentException - When namespaceURI is null

      • getPrefixes

        Iterator getPrefixes​(String namespaceURI)
        Get all prefixes bound to a Namespace URI in the current scope.

        An Iterator over String elements is returned in an arbitrary, implementation dependent, order.

        The Iterator is not modifiable. e.g. the remove() method will throw UnsupportedOperationException.

        When requesting prefixes by Namespace URI, the following table describes the returned prefixes value for all Namespace URI values:

        Return value for specified Namespace URIs
        Namespace URI parameter prefixes value returned
        bound Namespace URI, including the <default Namespace URI> Iterator over prefixes bound to Namespace URI in the current scope in an arbitrary, implementation dependent, order
        unbound Namespace URI empty Iterator
        XMLConstants.XML_NS_URI ("http://www.w3.org/XML/1998/namespace") Iterator with one element set to XMLConstants.XML_NS_PREFIX ("xml")
        XMLConstants.XMLNS_ATTRIBUTE_NS_URI ("http://www.w3.org/2000/xmlns/") Iterator with one element set to XMLConstants.XMLNS_ATTRIBUTE ("xmlns")
        null IllegalArgumentException is thrown
        Parameters:
        namespaceURI - URI of Namespace to lookup
        Returns:
        Iterator for all prefixes bound to the Namespace URI in the current scope
        Throws:
        IllegalArgumentException - When namespaceURI is null