/*
* Copyright 2005 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.xml.namespace;
import javax.xml.namespace.QName;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
import org.w3c.dom.Node;
/**
* Helper class for using {@link QName}.
*
* @author Arjen Poutsma
* @see javax.xml.namespace.QName
* @since 1.0.0
*/
public abstract class QNameUtils {
/** Indicates whether {@link QName} has a prefix. The first release of the class did not have this. */
private static boolean qNameHasPrefix;
static {
try {
QName.class.getDeclaredConstructor(new Class[]{String.class, String.class, String.class});
qNameHasPrefix = true;
}
catch (NoSuchMethodException e) {
qNameHasPrefix = false;
}
}
/**
* Creates a new <code>QName</code> with the given parameters. Sets the prefix if possible, i.e. if the
* <code>QName(String, String, String)</code> constructor can be found. If this constructor is not available (as is
* the case on older implementations of JAX-RPC), the prefix is ignored.
*
* @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>. May be ignored.
* @return the created <code>QName</code>
* @see QName#QName(String,String,String)
*/
public static QName createQName(String namespaceUri, String localPart, String prefix) {
if (qNameHasPrefix) {
return new QName(namespaceUri, localPart, prefix);
}
else {
return new QName(namespaceUri, localPart);
}
}
/**
* Returns the prefix of the given <code>QName</code>. Returns the prefix if available, i.e. if the
* <code>QName.getPrefix()</code> method can be found. If this method is not available (as is the case on older
* implementations of JAX-RPC), an empty string is returned.
*
* @param qName the <code>QName</code> to return the prefix from
* @return the prefix, if available, or an empty string
* @see javax.xml.namespace.QName#getPrefix()
*/
public static String getPrefix(QName qName) {
return qNameHasPrefix ? qName.getPrefix() : "";
}
/**
* Validates the given String as a QName
*
* @param text the qualified name
* @return <code>true</code> if valid, <code>false</code> otherwise
*/
public static boolean validateQName(String text) {
if (!StringUtils.hasLength(text)) {
return false;
}
if (text.charAt(0) == '{') {
int i = text.indexOf('}');
if (i == -1 || i == text.length() - 1) {
return false;
}
}
return true;
}
/**
* Returns the qualified name of the given DOM Node.
*
* @param node the node
* @return the qualified name of the node
*/
public static QName getQNameForNode(Node node) {
if (node.getNamespaceURI() != null && node.getPrefix() != null && node.getLocalName() != null) {
return createQName(node.getNamespaceURI(), node.getLocalName(), node.getPrefix());
}
else if (node.getNamespaceURI() != null && node.getLocalName() != null) {
return new QName(node.getNamespaceURI(), node.getLocalName());
}
else if (node.getLocalName() != null) {
return new QName(node.getLocalName());
}
else {
// as a last resort, use the node name
return new QName(node.getNodeName());
}
}
/**
* Convert a <code>QName</code> to a qualified name, as used by DOM and SAX. The returned string has a format of
* <code>prefix:localName</code> if the prefix is set, or just <code>localName</code> if not.
*
* @param qName the <code>QName</code>
* @return the qualified name
*/
public static String toQualifiedName(QName qName) {
String prefix = getPrefix(qName);
if (!StringUtils.hasLength(prefix)) {
return qName.getLocalPart();
}
else {
return prefix + ":" + qName.getLocalPart();
}
}
/**
* Convert a namespace URI and DOM or SAX qualified name to a <code>QName</code>. The qualified name can have the
* form <code>prefix:localname</code> or <code>localName</code>.
*
* @param namespaceUri the namespace URI
* @param qualifiedName the qualified name
* @return a QName
*/
public static QName toQName(String namespaceUri, String qualifiedName) {
int idx = qualifiedName.indexOf(':');
if (idx == -1) {
return new QName(namespaceUri, qualifiedName);
}
else {
return createQName(namespaceUri, qualifiedName.substring(idx + 1), qualifiedName.substring(0, idx));
}
}
/**
* Parse the given qualified name string into a <code>QName</code>. Expects the syntax <code>localPart</code>,
* <code>{namespace}localPart</code>, or <code>{namespace}prefix:localPart</code>. This format resembles the
* <code>toString()</code> representation of <code>QName</code> itself, but allows for prefixes to be specified as
* well.
*
* @return a corresponding QName instance
* @throws IllegalArgumentException when the given string is <code>null</code> or empty.
*/
public static QName parseQNameString(String qNameString) {
Assert.hasLength(qNameString, "QName text may not be null or empty");
if (qNameString.charAt(0) != '{') {
return new QName(qNameString);
}
else {
int endOfNamespaceURI = qNameString.indexOf('}');
if (endOfNamespaceURI == -1) {
throw new IllegalArgumentException(
"Cannot create QName from \"" + qNameString + "\", missing closing \"}\"");
}
int prefixSeperator = qNameString.indexOf(':', endOfNamespaceURI + 1);
String namespaceURI = qNameString.substring(1, endOfNamespaceURI);
if (prefixSeperator == -1) {
return new QName(namespaceURI, qNameString.substring(endOfNamespaceURI + 1));
}
else {
return createQName(namespaceURI, qNameString.substring(prefixSeperator + 1),
qNameString.substring(endOfNamespaceURI + 1, prefixSeperator));
}
}
}
}
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