Java XML QName Convert toString(final QName qname)

Description

to String

License

Apache License

Parameter

Parameter	Description
qname	The QName to serialize into prefix:localName form.

Return

This method returns a different value than QName.toString(). The QName.toString() returns a string of the format:

{namespace URI}:name

whereas this method returns:

prefix:name

which is a valid representation to put into XML documents. If the QName has no prefix, the local name is returned.

Declaration

public static String toString(final QName qname)

Method Source Code

//package com.java2s;
/* //  w w  w .ja  v a  2 s .  co m
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 *
 */

import java.io.IOException;

import java.io.StringWriter;

import javax.xml.namespace.QName;

import org.w3c.dom.Document;
import org.w3c.dom.Element;

import org.w3c.dom.Node;

import com.sun.org.apache.xml.internal.serialize.OutputFormat;
import com.sun.org.apache.xml.internal.serialize.XMLSerializer;

public class Main {
    /**
     * This is a convenience method that serializes the given XML tree
     * with the XML header and indentation; it is the equivalent of
     * calling toString(Node, boolean) with the last parameter set to
     * "true".
     * 
     * @see #toString(Node, boolean)
     */
    public static String toString(final Node xml) {
        return toString(xml, true);
    }

    /**
     * This is a convenience method that serializes the given XML tree
     * with indentation; the XML header is included if the second
     * parameter is "true".
     * 
     * @see #toString(Node, boolean, boolean)
     */
    public static String toString(final Node xml, final boolean printHeader) {
        return toString(xml, printHeader, true);
    }

    /**
     * Serializes the given XML tree to string form, including the standard
     * XML header and indentation if desired. This method relies on the
     * serialization API from Apache Xerces, since JAXP has on equivalent.
     * 
     * @param xml
     *            The XML tree to serialize.
     * @param printHeader
     *            True if you want the XML header printed before the XML.
     * @param printIndents
     *            True if you want pretty-printing - child elements will be
     *            indented with symmetry.
     * @return The string representation of the given Node.
     */
    public static String toString(final Node xml, final boolean printHeader, final boolean printIndents) {
        final short type = xml.getNodeType();

        if (type == Node.TEXT_NODE)
            return xml.getNodeValue();

        //
        // NOTE: This serialization code is not part of JAXP/DOM - it is 
        //       specific to Xerces and creates a Xerces dependency for 
        //       this class.
        //
        final XMLSerializer serializer = new XMLSerializer();
        serializer.setNamespaces(true);

        final OutputFormat formatter = new OutputFormat();
        formatter.setOmitXMLDeclaration(!printHeader);
        formatter.setIndenting(printIndents);
        serializer.setOutputFormat(formatter);

        final StringWriter writer = new StringWriter();
        serializer.setOutputCharStream(writer);

        try {
            if (type == Node.DOCUMENT_NODE)
                serializer.serialize((Document) xml);
            else
                serializer.serialize((Element) xml);
        }

        //
        // we are using a StringWriter, so this "should never happen". the 
        // StringWriter implementation writes to a StringBuffer, so there's 
        // no file I/O that could fail.
        //
        // if it DOES fail, we re-throw with a more serious error, because 
        // this a very common operation.
        //
        catch (final IOException error) {
            throw new RuntimeException(error.getMessage(), error);
        }

        return writer.toString();
    }

    /**
     * @param qname
     *            The QName to serialize into prefix:localName form.
     * @return This method returns a different value than QName.toString(). The
     *         QName.toString() returns a string of the format: <br>
     * <br>
     *         <em>{namespace URI}:name</em> <br>
     * <br>
     *         whereas this method returns: <br>
     * <br>
     *         <em>prefix:name</em> <br>
     * <br>
     *         which is a valid representation to put into XML documents. If
     *         the QName has no prefix, the local name is returned.
     */
    public static String toString(final QName qname) {
        final String prefix = qname.getPrefix();
        final String name = qname.getLocalPart();

        if (prefix == null || prefix.length() == 0)
            return name;

        return prefix + ':' + name;
    }
}