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 an XML input source
. The prefix is
NOT used in QName.equals(Object)
or to compute the QName.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 to XMLConstants.DEFAULT_NS_PREFIX
.
QName
is immutable.
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. |
Modifier and Type | Method and Description |
---|---|
boolean |
equals(Object objectToTest)
Test this
QName for equality with another
Object . |
String |
getLocalPart()
Get the local part of this
QName . |
String |
getNamespaceURI()
Get the Namespace URI of this
QName . |
String |
getPrefix()
Get the prefix of this
QName . |
int |
hashCode()
Generate the hash code for this
QName . |
String |
toString()
String representation of this
QName . |
static QName |
valueOf(String qNameAsString)
QName derived from parsing the formatted
String . |
public QName(String namespaceURI, String localPart)
QName
constructor specifying the Namespace URI
and local part.
If the Namespace URI is null
, it is set to
XMLConstants.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 the XMLConstants.NULL_NS_URI
value is the preferred coding
style.
If the local part is null
an
IllegalArgumentException
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.
namespaceURI
- Namespace URI of the QName
localPart
- local part of the QName
IllegalArgumentException
- When localPart
is
null
QName(String namespaceURI, String localPart, String
prefix)
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 to
XMLConstants.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 the XMLConstants.NULL_NS_URI
value is the preferred coding
style.
If the local part is null
an
IllegalArgumentException
is thrown.
A local part of "" is allowed to preserve
compatible behavior with QName 1.0.
If the prefix is null
, an
IllegalArgumentException
is thrown. Use XMLConstants.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.
namespaceURI
- Namespace URI of the QName
localPart
- local part of the QName
prefix
- prefix of the QName
IllegalArgumentException
- When localPart
or prefix
is null
public QName(String localPart)
QName
constructor specifying the local part.
If the local part is null
an
IllegalArgumentException
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 to XMLConstants.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 constructors QName(String
namespaceURI, String localPart)
and
QName(String namespaceURI, String localPart, String prefix)
are preferred.
The local part is not validated as a NCName as specified in Namespaces in XML.
localPart
- local part of the QName
IllegalArgumentException
- When localPart
is
null
QName(String
namespaceURI, String localPart)
,
QName(String namespaceURI, String localPart, String
prefix)
public String getNamespaceURI()
Get the Namespace URI of this QName
.
QName
public String getLocalPart()
Get the local part of this QName
.
QName
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, a QName
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.
QName
public final boolean equals(Object objectToTest)
Test this QName
for equality with another
Object
.
If the Object
to be tested is not a
QName
or is null
, then this method
returns false
.
Two QName
s are considered equal if and only if
both the Namespace URI and local part are equal. This method
uses String.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)
equals
in class Object
objectToTest
- the Object
to test for
equality with this QName
true
if the given Object
is
equal to this QName
else false
Object.hashCode()
,
HashMap
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()
.
hashCode
in class Object
QName
Object
Object.equals(java.lang.Object)
,
System.identityHashCode(java.lang.Object)
public String toString()
String
representation of this
QName
.
The commonly accepted way of representing a QName
as a String
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 a QName
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()
.
public static QName valueOf(String qNameAsString)
QName
derived from parsing the formatted
String
.
If the String
is null
or does not conform to
QName.toString()
formatting, an
IllegalArgumentException
is thrown.
The String
MUST be in the
form returned by QName.toString()
.
The commonly accepted way of representing a QName
as a String
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 a String
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 to
XMLConstants.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.
qNameAsString
- String
representation
of the QName
QName
corresponding to the given String
IllegalArgumentException
- When qNameAsString
is
null
or malformedQName.toString()
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