public QName(String localPart) 
{
        this(
            XMLConstants.NULL_NS_URI,
            localPart,
            XMLConstants.DEFAULT_NS_PREFIX);
}

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 namespaceURI, String localPart) QName(String 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.

Parameters:

localPart - local part of the QName

Also see:

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

 public QName(String namespaceURI,
    String localPart) 
{
        this(namespaceURI, localPart, XMLConstants.DEFAULT_NS_PREFIX);
}

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.

Parameters:

namespaceURI - Namespace URI of the QName

localPart - local part of the QName

Also see:

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

 public QName(String namespaceURI,
    String localPart,
    String prefix) 
{
        // map null Namespace URI to default to preserve compatibility with QName 1.0
        if (namespaceURI == null) {
            this.namespaceURI = XMLConstants.NULL_NS_URI;
        } else {
            this.namespaceURI = namespaceURI;
        }
        // local part is required.  "" is allowed to preserve compatibility with QName 1.0        
        if (localPart == null) {
            throw new IllegalArgumentException("local part cannot be \"null\" when creating a QName");
        }
        this.localPart = localPart;
        // prefix is required        
        if (prefix == null) {
            throw new IllegalArgumentException("prefix cannot be \"null\" when creating a QName");
        }
        this.prefix = 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.

Parameters:

namespaceURI - Namespace URI of the QName

localPart - local part of the QName

prefix - prefix of the QName

 public final boolean equals(Object objectToTest) 
{
        // Is this the same object?
        if (objectToTest == this) {
            return true;
        }
        // Is this a QName?
        if (objectToTest instanceof QName) {
            QName qName = (QName) objectToTest;
            return localPart.equals(qName.localPart) && namespaceURI.equals(qName.namespaceURI);
        }
        return false;
}

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)

 public String getLocalPart() 
{
        return localPart;
}

Get the local part of this QName.

 public String getNamespaceURI() 
{
        return namespaceURI;
}

Get the Namespace URI of this QName.

 public String getPrefix() 
{
        return prefix;
}

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.

 public final int hashCode() 
{
        return namespaceURI.hashCode() ^ localPart.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() .

 public String toString() 
{
        String _qNameAsString = qNameAsString;
        if (_qNameAsString == null) {
            final int nsLength = namespaceURI.length();
            if (nsLength == 0) {
                _qNameAsString = localPart;
            }
            else {
                StringBuffer buffer = new StringBuffer(nsLength + localPart.length() + 2);
                buffer.append('{');
                buffer.append(namespaceURI);
                buffer.append('}');
                buffer.append(localPart);
                _qNameAsString = buffer.toString();
            }
            qNameAsString = _qNameAsString;
        }
        return _qNameAsString;
}

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. javax.xml.transform.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) 
{
        // null is not valid
        if (qNameAsString == null) {
            throw new IllegalArgumentException("cannot create QName from \"null\" or \"\" String");
        }
        // "" local part is valid to preserve compatible behavior with QName 1.0
        if (qNameAsString.length() == 0) {
            return new QName(
                XMLConstants.NULL_NS_URI,
                qNameAsString,
                XMLConstants.DEFAULT_NS_PREFIX);
        }
        // local part only?
        if (qNameAsString.charAt(0) != '{') {
            return new QName(
                XMLConstants.NULL_NS_URI,
                qNameAsString,
                XMLConstants.DEFAULT_NS_PREFIX);
        }
        // Namespace URI improperly specified?
        if (qNameAsString.startsWith("{" + XMLConstants.NULL_NS_URI + "}")) {
            throw new IllegalArgumentException(
                "Namespace URI .equals(XMLConstants.NULL_NS_URI), "
                + ".equals(\"" + XMLConstants.NULL_NS_URI + "\"), "
                + "only the local part, "
                + "\"" + qNameAsString.substring(2 + XMLConstants.NULL_NS_URI.length()) + "\", "
                + "should be provided.");
        }
        // Namespace URI and local part specified
        int endOfNamespaceURI = qNameAsString.indexOf('}');
        if (endOfNamespaceURI == -1) {
            throw new IllegalArgumentException(
                "cannot create QName from \""
                    + qNameAsString
                    + "\", missing closing \"}\"");
        }
        return new QName(
            qNameAsString.substring(1, endOfNamespaceURI),
            qNameAsString.substring(endOfNamespaceURI + 1),
            XMLConstants.DEFAULT_NS_PREFIX);
}

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. javax.xml.transform.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.