Utils.java Source code

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Here is the source code for Utils.java

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/**
 * 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.util.List;

import javax.xml.XMLConstants;

import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;

/**
 * Few simple utils to read DOM. This is originally from the Jakarta Commons Modeler.
 * 
 * @author Costin Manolache
 */
public class Utils {
    private static final String XMLNAMESPACE = "xmlns";

    /**
     * Starting from a node, find the namespace declaration for a prefix. for a matching namespace
     * declaration.
     * 
     * @param node search up from here to search for namespace definitions
     * @param searchPrefix the prefix we are searching for
     * @return the namespace if found.
     */
    public static String getNamespace(Node node, String searchPrefix) {

        Element el;
        while (!(node instanceof Element)) {
            node = node.getParentNode();
        }
        el = (Element) node;

        NamedNodeMap atts = el.getAttributes();
        for (int i = 0; i < atts.getLength(); i++) {
            Node currentAttribute = atts.item(i);
            String currentLocalName = currentAttribute.getLocalName();
            String currentPrefix = currentAttribute.getPrefix();
            if (searchPrefix.equals(currentLocalName) && XMLNAMESPACE.equals(currentPrefix)) {
                return currentAttribute.getNodeValue();
            } else if (isEmpty(searchPrefix) && XMLNAMESPACE.equals(currentLocalName) && isEmpty(currentPrefix)) {
                return currentAttribute.getNodeValue();
            }
        }

        Node parent = el.getParentNode();
        if (parent instanceof Element) {
            return getNamespace((Element) parent, searchPrefix);
        }

        return null;
    }

    public static boolean isEmpty(String str) {
        return str == null || str.length() == 0;
    }
}