Class QName
- java.lang.Object
-
- javax.xml.namespace.QName
-
- All Implemented Interfaces:
- Serializable
public class QName extends Object implements Serializable
QName
represents a qualified name as defined in the XML specifications: XML Schema Part2: Datatypes specification, Namespaces in XML, Namespaces in XML Errata.The value of a
QName
contains a Namespace URI, local part and prefix.The prefix is included in
QName
to retain lexical information when present in anXML input source
. The prefix is NOT used inQName.equals(Object)
or to compute theQName.hashCode()
. Equality and the hash code are defined using only the Namespace URI and local part.If not specified, the Namespace URI is set to
XMLConstants.NULL_NS_URI
. If not specified, the prefix is set toXMLConstants.DEFAULT_NS_PREFIX
.QName
is immutable.- Since:
- 1.5
- Version:
- $Revision: 1.8 $, $Date: 2010/03/18 03:06:17 $
- See Also:
- XML Schema Part2: Datatypes specification, Namespaces in XML, Namespaces in XML Errata, Serialized Form
-
-
Constructor Summary
Constructors Constructor and Description QName(String localPart)
QName
constructor specifying the local part.QName(String namespaceURI, String localPart)
QName
constructor specifying the Namespace URI and local part.QName(String namespaceURI, String localPart, String prefix)
QName
constructor specifying the Namespace URI, local part and prefix.
-
Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method and Description boolean
equals(Object objectToTest)
Test thisQName
for equality with anotherObject
.String
getLocalPart()
Get the local part of thisQName
.String
getNamespaceURI()
Get the Namespace URI of thisQName
.String
getPrefix()
Get the prefix of thisQName
.int
hashCode()
Generate the hash code for thisQName
.String
toString()
String
representation of thisQName
.static QName
valueOf(String qNameAsString)
QName
derived from parsing the formattedString
.
-
-
-
Constructor Detail
QName
public QName(String namespaceURI, String localPart)
QName
constructor specifying the Namespace URI and local part.If the Namespace URI is
null
, it is set toXMLConstants.NULL_NS_URI
. This value represents no explicitly defined Namespace as defined by the Namespaces in XML specification. This action preserves compatible behavior with QName 1.0. Explicitly providing theXMLConstants.NULL_NS_URI
value is the preferred coding style.If the local part is
null
anIllegalArgumentException
is thrown. A local part of "" is allowed to preserve compatible behavior with QName 1.0.When using this constructor, the prefix is set to
XMLConstants.DEFAULT_NS_PREFIX
.The Namespace URI is not validated as a URI reference. The local part is not validated as a NCName as specified in Namespaces in XML.
- Parameters:
-
namespaceURI
- Namespace URI of theQName
-
localPart
- local part of theQName
- Throws:
-
IllegalArgumentException
- WhenlocalPart
isnull
- See Also:
-
QName(String namespaceURI, String localPart, String prefix)
QName
public QName(String namespaceURI, String localPart, String prefix)
QName
constructor specifying the Namespace URI, local part and prefix.If the Namespace URI is
null
, it is set toXMLConstants.NULL_NS_URI
. This value represents no explicitly defined Namespace as defined by the Namespaces in XML specification. This action preserves compatible behavior with QName 1.0. Explicitly providing theXMLConstants.NULL_NS_URI
value is the preferred coding style.If the local part is
null
anIllegalArgumentException
is thrown. A local part of "" is allowed to preserve compatible behavior with QName 1.0.If the prefix is
null
, anIllegalArgumentException
is thrown. UseXMLConstants.DEFAULT_NS_PREFIX
to explicitly indicate that no prefix is present or the prefix is not relevant.The Namespace URI is not validated as a URI reference. The local part and prefix are not validated as a NCName as specified in Namespaces in XML.
- Parameters:
-
namespaceURI
- Namespace URI of theQName
-
localPart
- local part of theQName
-
prefix
- prefix of theQName
- Throws:
-
IllegalArgumentException
- WhenlocalPart
orprefix
isnull
QName
public QName(String localPart)
QName
constructor specifying the local part.If the local part is
null
anIllegalArgumentException
is thrown. A local part of "" is allowed to preserve compatible behavior with QName 1.0.When using this constructor, the Namespace URI is set to
XMLConstants.NULL_NS_URI
and the prefix is set toXMLConstants.DEFAULT_NS_PREFIX
.In an XML context, all Element and Attribute names exist in the context of a Namespace. Making this explicit during the construction of a
QName
helps prevent hard to diagnosis XML validity errors. The constructorsQName(String namespaceURI, String localPart)
andQName(String namespaceURI, String localPart, String prefix)
are preferred.The local part is not validated as a NCName as specified in Namespaces in XML.
- Parameters:
-
localPart
- local part of theQName
- Throws:
-
IllegalArgumentException
- WhenlocalPart
isnull
- See Also:
-
QName(String namespaceURI, String localPart)
,QName(String namespaceURI, String localPart, String prefix)
-
Method Detail
getNamespaceURI
public String getNamespaceURI()
Get the Namespace URI of this
QName
.- Returns:
-
Namespace URI of this
QName
getLocalPart
public String getLocalPart()
Get the local part of this
QName
.- Returns:
-
local part of this
QName
getPrefix
public String getPrefix()
Get the prefix of this
QName
.The prefix assigned to a
QName
might NOT be valid in a different context. For example, aQName
may be assigned a prefix in the context of parsing a document but that prefix may be invalid in the context of a different document.- Returns:
-
prefix of this
QName
equals
public final boolean equals(Object objectToTest)
Test this
QName
for equality with anotherObject
.If the
Object
to be tested is not aQName
or isnull
, then this method returnsfalse
.Two
QName
s are considered equal if and only if both the Namespace URI and local part are equal. This method usesString.equals()
to check equality of the Namespace URI and local part. The prefix is NOT used to determine equality.This method satisfies the general contract of
Object.equals(Object)
- Overrides:
-
equals
in classObject
- Parameters:
-
objectToTest
- theObject
to test for equality with thisQName
- Returns:
-
true
if the givenObject
is equal to thisQName
elsefalse
- See Also:
-
Object.hashCode()
,HashMap
hashCode
public final int hashCode()
Generate the hash code for this
QName
.The hash code is calculated using both the Namespace URI and the local part of the
QName
. The prefix is NOT used to calculate the hash code.This method satisfies the general contract of
Object.hashCode()
.- Overrides:
-
hashCode
in classObject
- Returns:
-
hash code for this
QName
Object
- See Also:
-
Object.equals(java.lang.Object)
,System.identityHashCode(java.lang.Object)
toString
public String toString()
String
representation of thisQName
.The commonly accepted way of representing a
QName
as aString
was defined by James Clark. Although this is not a standard specification, it is in common use, e.g.Transformer.setParameter(String name, Object value)
. This implementation represents aQName
as: "{" + Namespace URI + "}" + local part. If the Namespace URI.equals(XMLConstants.NULL_NS_URI)
, only the local part is returned. An appropriate use of this method is for debugging or logging for human consumption.Note the prefix value is NOT returned as part of the
String
representation.This method satisfies the general contract of
Object.toString()
.
valueOf
public static QName valueOf(String qNameAsString)
QName
derived from parsing the formattedString
.If the
String
isnull
or does not conform toQName.toString()
formatting, anIllegalArgumentException
is thrown.The
String
MUST be in the form returned byQName.toString()
.The commonly accepted way of representing a
QName
as aString
was defined by James Clark. Although this is not a standard specification, it is in common use, e.g.Transformer.setParameter(String name, Object value)
. This implementation parses aString
formatted as: "{" + Namespace URI + "}" + local part. If the Namespace URI.equals(XMLConstants.NULL_NS_URI)
, only the local part should be provided.The prefix value CANNOT be represented in the
String
and will be set toXMLConstants.DEFAULT_NS_PREFIX
.This method does not do full validation of the resulting
QName
.The Namespace URI is not validated as a URI reference. The local part is not validated as a NCName as specified in Namespaces in XML.
- Parameters:
-
qNameAsString
-String
representation of theQName
- Returns:
-
QName
corresponding to the givenString
- Throws:
-
IllegalArgumentException
- WhenqNameAsString
isnull
or malformed - See Also:
-
QName.toString()
-
Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 1993, 2022, Oracle and/or its affiliates. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.