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

Method Summary

Modifier and Type	Method	Description
String	getNamespaceURI(String prefix)	Get Namespace URI bound to a prefix in the current scope.
String	getPrefix(String namespaceURI)	Get prefix bound to Namespace URI in the current scope.
Iterator<String>	getPrefixes(String namespaceURI)	Get all prefixes bound to a Namespace URI in the current scope.

Method Details

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<String> 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