javax.xml.namespace
Class QName

java.lang.Object
  javax.xml.namespace.QName

All Implemented Interfaces:

java.io.Serializable

public class QName
extends java.lang.Object
implements java.io.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 "" (the empty string). If not specified, the prefix is set to "" (the empty string).

QName is immutable.

See Also:

XML Schema Part2: Datatypes specification, Namespaces in XML, Namespaces in XML Errata, Serialized Form

Constructor Summary

QName(java.lang.String localPart)
QName constructor specifying the local part.

QName(java.lang.String namespaceURI, java.lang.String localPart)
QName constructor specifying the Namespace URI and local part.

QName(java.lang.String namespaceURI, java.lang.String localPart, java.lang.String prefix)
QName constructor specifying the Namespace URI, local part and prefix.

Method Summary

boolean	equals(java.lang.Object objectToTest) Test this QName for equality with another Object.
java.lang.String	getLocalPart() Get the local part of this QName.
java.lang.String	getNamespaceURI() Get the Namespace URI of this QName.
java.lang.String	getPrefix() Get the prefix of this QName.
int	hashCode() Generate the hash code for this QName.
java.lang.String	toString() String representation of this QName.
static QName	valueOf(java.lang.String qNameAsString) QName derived from parsing the formatted String.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

QName

public QName(java.lang.String namespaceURI,
             java.lang.String localPart)

QName constructor specifying the Namespace URI and local part.

If the Namespace URI is null, it is set to "". This value represents no explicitly defined Namespace as defined by the Namespaces in XML specification. This action preserves compatible behavior with QName 1.0.

If the local part is null, an IllegalArgumentException is thrown.

When using this constructor, the prefix is set to "".

Parameters:

namespaceURI - Namespace URI of the QName

localPart - local part of the QName

See Also:

QName(String namespaceURI, String localPart, String prefix)

QName

public QName(java.lang.String namespaceURI,
             java.lang.String localPart,
             java.lang.String prefix)

QName constructor specifying the Namespace URI, local part and prefix.

If the Namespace URI is null, it is set to "". This value represents no explicitly defined Namespace as defined by the Namespaces in XML specification. This action preserves compatible behavior with QName 1.0.

If the local part is null, an IllegalArgumentException is thrown.

If the prefix is null, an IllegalArgumentException is thrown. Use "" to explicitly indicate that no prefix is present or the prefix is not relevant.

Parameters:

namespaceURI - Namespace URI of the QName

localPart - local part of the QName

prefix - prefix of the QName

QName

public QName(java.lang.String localPart)

QName constructor specifying the local part.

If the local part is null or .equals(""), an IllegalArgumentException is thrown.

When using this constructor, the Namespace URI is set to "" and the prefix is set to "".

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 to prevent hard to diagnosis XML validity errors. The constructors QName(String namespaceURI, String localPart) and QName(String namespaceURI, String localPart, String prefix) are preferred.

Parameters:

localPart - local part of the QName

See Also:

QName(String namespaceURI, String localPart), QName(String namespaceURI, String localPart, String prefix)

Method Detail

getNamespaceURI

public java.lang.String getNamespaceURI()

Get the Namespace URI of this QName.

Returns:

Namespace URI of this QName

getLocalPart

public java.lang.String getLocalPart()

Get the local part of this QName.

Returns:

local part of this QName

getPrefix

public java.lang.String getPrefix()

Get the prefix of this QName.

The prefix assigned to a QName may 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.

Returns:

prefix of this QName

equals

public boolean equals(java.lang.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 QNames 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)

Overrides:

equals in class java.lang.Object

Parameters:

objectToTest - the Object to test for equality with this QName

Returns:

true if the given Object is equal to this QName else false

hashCode

public 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 class java.lang.Object

Returns:

hash code for this QName Object

toString

public java.lang.String toString()

String representation of this QName.

There is NO standard specification for representing a QName as a String. The returned String is not portable across implementations and will change when a standard String representation is defined. This implementation currently represents a QName as: "{" + Namespace URI + "}" + local part. If the Namespace URI .equals(""), 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().

Overrides:

toString in class java.lang.Object

Returns:

String representation of this QName

valueOf

public static QName valueOf(java.lang.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(). There is NO standard specification for representing a QName as a String. The String format is NOT portable across implementations and will change when a standard String representation is defined. This implementation currently parses a String formatted as: "{" + Namespace URI + "}" + local part. If the Namespace URI .equals(""), only the local part should be provided.

The prefix value CANNOT be represented in the String and will be set to ""

This method does not do full validation of the resulting QName. In particular, the local part is not validated as a NCName as specified in Namespaces in XML.

Parameters:

qNameAsString - String representation of the QName

Returns:

QName corresponding to the given String

See Also:

QName.toString()