- // $Id: QName.java,v 1.10 2004/02/09 23:41:21 jsuttor Exp $
-
- /*
- * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
- * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
- */
-
- package javax.xml.namespace;
-
- import java.io.Serializable;
-
- import javax.xml.XMLConstants;
-
- /**
- * <p><code>QName</code> represents a <strong>qualified name</strong>
- * as defined in the XML specifications: <a
- * href="http://www.w3.org/TR/xmlschema-2/#QName">XML Schema Part2:
- * Datatypes specification</a>, <a
- * href="http://www.w3.org/TR/REC-xml-names/#ns-qualnames">Namespaces
- * in XML</a>, <a
- * href="http://www.w3.org/XML/xml-names-19990114-errata">Namespaces
- * in XML Errata</a>.</p>
- *
- * <p>The value of a <code>QName</code> contains a <strong>Namespace
- * URI</strong>, <strong>local part</strong> and
- * <strong>prefix</strong>.</p>
- *
- * <p>The prefix is included in <code>QName</code> to retain lexical
- * information <strong><em>when present</em></strong> in an {@link
- * javax.xml.transform.Source XML input source}. The prefix is
- * <strong><em>NOT</em></strong> used in {@link #equals(Object)
- * QName.equals(Object)} or to compute the {@link #hashCode()
- * QName.hashCode()}. Equality and the hash code are defined using
- * <strong><em>only</em></strong> the Namespace URI and local part.</p>
- *
- * <p>If not specified, the Namespace URI is set to {@link
- * javax.xml.XMLConstants#NULL_NS_URI XMLConstants.NULL_NS_URI}.
- * If not specified, the prefix is set to {@link
- * javax.xml.XMLConstants#DEFAULT_NS_PREFIX
- * XMLConstants.DEFAULT_NS_PREFIX}.</p>
- *
- * <p><code>QName</code> is immutable.</p>
- *
- * @author <a href="mailto:Jeff.Suttor@Sun.com">Jeff Suttor</a>
- * @version $Revision: 1.10 $, $Date: 2004/02/09 23:41:21 $
- * @see <a href="http://www.w3.org/TR/xmlschema-2/#QName">XML Schema Part2: Datatypes specification</a>
- * @see <a href="http://www.w3.org/TR/REC-xml-names/#ns-qualnames">Namespaces in XML</a>
- * @see <a href="http://www.w3.org/XML/xml-names-19990114-errata">Namespaces in XML Errata</a>
- * @since 1.5
- */
-
- public class QName implements Serializable {
-
- /**
- * <p>Stream Unique Identifier.</p>
- */
- private static final long serialVersionUID = 4418622981026545151L;
-
- /**
- * <p>Namespace URI of this <code>QName</code>.</p>
- */
- private final String namespaceURI;
-
- /**
- * <p>local part of this <code>QName</code>.</p>
- */
- private final String localPart;
-
- /**
- * <p>prefix of this <code>QName</code>.</p>
- */
- private final String prefix;
-
- /**
- * <p><code>QName</code> constructor specifying the Namespace URI
- * and local part.</p>
- *
- * <p>If the Namespace URI is <code>null</code>, it is set to
- * {@link javax.xml.XMLConstants#NULL_NS_URI
- * XMLConstants.NULL_NS_URI}. This value represents no
- * explicitly defined Namespace as defined by the <a
- * href="http://www.w3.org/TR/REC-xml-names/#ns-qualnames">Namespaces
- * in XML</a> specification. This action preserves compatible
- * behavior with QName 1.0. Explicitly providing the {@link
- * javax.xml.XMLConstants#NULL_NS_URI
- * XMLConstants.NULL_NS_URI} value is the preferred coding
- * style.</p>
- *
- * <p>If the local part is <code>null</code> an
- * <code>IllegalArgumentException</code> is thrown.
- * A local part of "" is allowed to preserve
- * compatible behavior with QName 1.0. </p>
- *
- * <p>When using this constructor, the prefix is set to {@link
- * javax.xml.XMLConstants#DEFAULT_NS_PREFIX
- * XMLConstants.DEFAULT_NS_PREFIX}.</p>
- *
- * <p>The Namespace URI is not validated as a
- * <a href="http://www.ietf.org/rfc/rfc2396.txt">URI reference</a>.
- * The local part is not validated as a
- * <a href="http://www.w3.org/TR/REC-xml-names/#NT-NCName">NCName</a>
- * as specified in <a href="http://www.w3.org/TR/REC-xml-names/">Namespaces
- * in XML</a>.</p>
- *
- * @param namespaceURI Namespace URI of the <code>QName</code>
- * @param localPart local part of the <code>QName</code>
- *
- * @see #QName(String namespaceURI, String localPart, String
- * prefix) QName(String namespaceURI, String localPart, String
- * prefix)
- */
- public QName(final String namespaceURI, final String localPart) {
- this(namespaceURI, localPart, XMLConstants.DEFAULT_NS_PREFIX);
- }
-
- /**
- * <p><code>QName</code> constructor specifying the Namespace URI,
- * local part and prefix.</p>
- *
- * <p>If the Namespace URI is <code>null</code>, it is set to
- * {@link javax.xml.XMLConstants#NULL_NS_URI
- * XMLConstants.NULL_NS_URI}. This value represents no
- * explicitly defined Namespace as defined by the <a
- * href="http://www.w3.org/TR/REC-xml-names/#ns-qualnames">Namespaces
- * in XML</a> specification. This action preserves compatible
- * behavior with QName 1.0. Explicitly providing the {@link
- * javax.xml.XMLConstants#NULL_NS_URI
- * XMLConstants.NULL_NS_URI} value is the preferred coding
- * style.</p>
- *
- * <p>If the local part is <code>null</code> an
- * <code>IllegalArgumentException</code> is thrown.
- * A local part of "" is allowed to preserve
- * compatible behavior with QName 1.0. </p>
- *
- * <p>If the prefix is <code>null</code>, an
- * <code>IllegalArgumentException</code> is thrown. Use {@link
- * javax.xml.XMLConstants#DEFAULT_NS_PREFIX
- * XMLConstants.DEFAULT_NS_PREFIX} to explicitly indicate that no
- * prefix is present or the prefix is not relevant.</p>
- *
- * <p>The Namespace URI is not validated as a
- * <a href="http://www.ietf.org/rfc/rfc2396.txt">URI reference</a>.
- * The local part and prefix are not validated as a
- * <a href="http://www.w3.org/TR/REC-xml-names/#NT-NCName">NCName</a>
- * as specified in <a href="http://www.w3.org/TR/REC-xml-names/">Namespaces
- * in XML</a>.</p>
- *
- * @param namespaceURI Namespace URI of the <code>QName<code>
- * @param localPart local part of the <code>QName<code>
- * @param prefix prefix of the <code>QName<code>
- */
- 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;
- }
-
- /**
- * <p><code>QName</code> constructor specifying the local part.</p>
- *
- * <p>If the local part is <code>null</code> an
- * <code>IllegalArgumentException</code> is thrown.
- * A local part of "" is allowed to preserve
- * compatible behavior with QName 1.0. </p>
- *
- * <p>When using this constructor, the Namespace URI is set to
- * {@link javax.xml.XMLConstants#NULL_NS_URI
- * XMLConstants.NULL_NS_URI} and the prefix is set to {@link
- * javax.xml.XMLConstants#DEFAULT_NS_PREFIX
- * XMLConstants.DEFAULT_NS_PREFIX}.</p>
- *
- * <p><em>In an XML context, all Element and Attribute names exist
- * in the context of a Namespace. Making this explicit during the
- * construction of a <code>QName</code> helps prevent hard to
- * diagnosis XML validity errors. The constructors {@link
- * #QName(String namespaceURI, String localPart) QName(String
- * namespaceURI, String localPart)} and
- * {@link #QName(String namespaceURI, String localPart, String prefix)}
- * are preferred.</em></p>
- *
- * <p>The local part is not validated as a
- * <a href="http://www.w3.org/TR/REC-xml-names/#NT-NCName">NCName</a>
- * as specified in <a href="http://www.w3.org/TR/REC-xml-names/">Namespaces
- * in XML</a>.</p>
- *
- * @param localPart local part of the <code>QName</code>
- * @see #QName(String namespaceURI, String localPart) QName(String
- * namespaceURI, String localPart)
- * @see #QName(String namespaceURI, String localPart, String
- * prefix) QName(String namespaceURI, String localPart, String
- * prefix)
- */
- public QName(String localPart) {
- this(
- XMLConstants.NULL_NS_URI,
- localPart,
- XMLConstants.DEFAULT_NS_PREFIX);
- }
-
- /**
- * <p>Get the Namespace URI of this <code>QName</code>.</p>
- *
- * @return Namespace URI of this <code>QName</code>
- */
- public String getNamespaceURI() {
- return namespaceURI;
- }
-
- /**
- * <p>Get the local part of this <code>QName</code>.</p>
- *
- * @return local part of this <code>QName</code>
- */
- public String getLocalPart() {
- return localPart;
- }
-
- /**
- * <p>Get the prefix of this <code>QName</code>.</p>
- *
- * <p>The prefix assigned to a <code>QName</code> might
- * <strong><em>NOT</em></strong> be valid in a different
- * context. For example, a <code>QName</code> 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.</p>
- *
- * @return prefix of this <code>QName</code>
- */
- public String getPrefix() {
- return prefix;
- }
-
- /**
- * <p>Test this <code>QName</code> for equality with another
- * <code>Object</code>.</p>
- *
- * <p>If the <code>Object</code> to be tested is not a
- * <code>QName</code> or is <code>null</code>, then this method
- * returns <code>false</code>.</p>
- *
- * <p>Two <code>QName</code>s are considered equal if and only if
- * both the Namespace URI and local part are equal. This method
- * uses <code>String.equals()</code> to check equality of the
- * Namespace URI and local part. The prefix is
- * <strong><em>NOT</em></strong> used to determine equality.</p>
- *
- * <p>This method satisfies the general contract of {@link
- * java.lang.Object#equals(Object) Object.equals(Object)}</p>
- *
- * @param objectToTest the <code>Object</code> to test for
- * equality with this <code>QName</code>
- * @return <code>true</code> if the given <code>Object</code> is
- * equal to this <code>QName</code> else <code>false</code>
- */
- public final boolean equals(Object objectToTest) {
- if (objectToTest == null || !(objectToTest instanceof QName)) {
- return false;
- }
-
- QName qName = (QName) objectToTest;
-
- return namespaceURI.equals(qName.namespaceURI)
- && localPart.equals(qName.localPart);
- }
-
- /**
- * <p>Generate the hash code for this <code>QName</code>.</p>
- *
- * <p>The hash code is calculated using both the Namespace URI and
- * the local part of the <code>QName</code>. The prefix is
- * <strong><em>NOT</em></strong> used to calculate the hash
- * code.</p>
- *
- * <p>This method satisfies the general contract of {@link
- * java.lang.Object#hashCode() Object.hashCode()}.</p>
- *
- * @return hash code for this <code>QName</code> <code>Object</code>
- */
- public final int hashCode() {
- return namespaceURI.hashCode() ^ localPart.hashCode();
- }
-
- /**
- * <p><code>String</code> representation of this
- * <code>QName</code>.</p>
- *
- * <p>The commonly accepted way of representing a <code>QName</code>
- * as a <code>String</code> was <a href="http://jclark.com/xml/xmlns.htm">defined</a>
- * by James Clark. Although this is not a <em>standard</em>
- * specification, it is in common use, e.g. {@link javax.xml.transform.Transformer#setParameter(String name, Object value)}.
- * This implementation represents a <code>QName</code> as:
- * "{" + Namespace URI + "}" + local part. If the Namespace URI
- * <code>.equals(XMLConstants.NULL_NS_URI)</code>, only the
- * local part is returned. An appropriate use of this method is
- * for debugging or logging for human consumption.</p>
- *
- * <p>Note the prefix value is <strong><em>NOT</em></strong>
- * returned as part of the <code>String</code> representation.</p>
- *
- * <p>This method satisfies the general contract of {@link
- * java.lang.Object#toString() Object.toString()}.</p>
- *
- * @return <code>String</code> representation of this <code>QName</code>
- */
- public String toString() {
- if (namespaceURI.equals(XMLConstants.NULL_NS_URI)) {
- return localPart;
- } else {
- return "{" + namespaceURI + "}" + localPart;
- }
- }
-
- /**
- * <p><code>QName</code> derived from parsing the formatted
- * <code>String</code>.</p>
- *
- * <p>If the <code>String</code> is <code>null</code> or does not conform to
- * {@link #toString() QName.toString()} formatting, an
- * <code>IllegalArgumentException</code> is thrown.</p>
- *
- * <p><em>The <code>String</code> <strong>MUST</strong> be in the
- * form returned by {@link #toString() QName.toString()}.</em></p>
-
- * <p>The commonly accepted way of representing a <code>QName</code>
- * as a <code>String</code> was <a href="http://jclark.com/xml/xmlns.htm">defined</a>
- * by James Clark. Although this is not a <em>standard</em>
- * specification, it is in common use, e.g. {@link javax.xml.transform.Transformer#setParameter(String name, Object value)}.
- * This implementation parses a <code>String</code> formatted
- * as: "{" + Namespace URI + "}" + local part. If the Namespace
- * URI <code>.equals(XMLConstants.NULL_NS_URI)</code>, only the
- * local part should be provided.</p>
- *
- * <p>The prefix value <strong><em>CANNOT</em></strong> be
- * represented in the <code>String</code> and will be set to
- * {@link javax.xml.XMLConstants#DEFAULT_NS_PREFIX
- * XMLConstants.DEFAULT_NS_PREFIX}.</p>
- *
- * <p>This method does not do full validation of the resulting
- * <code>QName</code>.
- * <p>The Namespace URI is not validated as a
- * <a href="http://www.ietf.org/rfc/rfc2396.txt">URI reference</a>.
- * The local part is not validated as a
- * <a href="http://www.w3.org/TR/REC-xml-names/#NT-NCName">NCName</a>
- * as specified in
- * <a href="http://www.w3.org/TR/REC-xml-names/">Namespaces in XML</a>.</p>
- *
- * @param qNameAsString <code>String</code> representation
- * of the <code>QName</code>
- * @return <code>QName</code> corresponding to the given <code>String</code>
- * @see #toString() QName.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);
- }
- }