org.eclipse.smila.processing.pipelets.xmlprocessing.util.XPathUtils.java Source code

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Here is the source code for org.eclipse.smila.processing.pipelets.xmlprocessing.util.XPathUtils.java

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/***********************************************************************************************************************
 * Copyright (c) 2008 empolis GmbH and brox IT Solutions GmbH. All rights reserved. This program and the accompanying
 * materials are made available under the terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors: Daniel Stucky (empolis GmbH) - initial API and implementation
 **********************************************************************************************************************/
package org.eclipse.smila.processing.pipelets.xmlprocessing.util;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.xpath.XPathAPI;
import org.apache.xpath.axes.NodeSequence;
import org.apache.xpath.objects.XBoolean;
import org.apache.xpath.objects.XNumber;
import org.apache.xpath.objects.XObject;
import org.apache.xpath.objects.XRTreeFrag;
import org.apache.xpath.objects.XString;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * To change the template for this generated type comment go to Window>Preferences>Java>Code Generation>Code
 * and Comments.
 */
public final class XPathUtils {

    /**
     * Default Constructor.
     */
    private XPathUtils() {
    }

    /**
     * Queries for index field.
     * 
     * @param node
     *          the Node
     * @param xpath
     *          the XPath
     * @param namespaceNode
     *          the namespace
     * @param separator
     *          the seperator
     * @return a Object (String, Double, Boolean)
     */
    public static Object queryForIndexField(Node node, String xpath, Node namespaceNode, String separator) {
        final Log log = LogFactory.getLog(XPathUtils.class);
        try {
            final XObject xobj = XPathAPI.eval(node, xpath, namespaceNode);

            if (xobj instanceof NodeSequence) {
                final NodeList nlTemp = xobj.nodelist();

                final StringBuffer sb = new StringBuffer("");
                for (int i = 0; i < nlTemp.getLength(); i++) {

                    final XObject value = XPathAPI.eval(nlTemp.item(i), "string()");
                    if ((i > 0) && (separator != null)) {
                        sb.append(separator);
                    }
                    sb.append(value.str());
                }
                return sb.toString();
            } else if (xobj instanceof XBoolean) {
                return Boolean.valueOf(xobj.bool());
            } else if (xobj instanceof XNumber) {
                return new Double(xobj.num());
            } else if (xobj instanceof XRTreeFrag) {
                return xobj.str();
            } else if (xobj instanceof XString) {
                return xobj.str();
            } else {
                throw new Exception("unsupported xpath return type [" + xobj.getClass().getName() + "]");
            }
        } catch (final Exception e) {
            log.error("unkown error occured", e);
            return null;
        }
    }

    /**
     * Removes nodes by XPath.
     * 
     * @param node
     *          the Node
     * @param xpath
     *          the XPath
     * @param namespaceNode
     *          the namespace
     */
    public static void removeNodesByXPath(Node node, String xpath, Node namespaceNode) {

        final Log log = LogFactory.getLog(XPathUtils.class);

        try {

            final XObject xobj = XPathAPI.eval(node, xpath, namespaceNode);

            if (xobj instanceof NodeSequence) {
                final NodeList nlTemp = xobj.nodelist();

                for (int i = 0; i < nlTemp.getLength(); i++) {
                    final Node parent = nlTemp.item(i).getParentNode();
                    parent.removeChild(nlTemp.item(i));
                }
                /*
                 * } else if (xobj instanceof XBoolean) { xobj.nodelist() return new Boolean(xobj.bool()); } else if (xobj
                 * instanceof XNumber) { return new Double(xobj.num()); } else if (xobj instanceof XRTreeFrag) { return
                 * xobj.str(); } else if (xobj instanceof XString) { return xobj.str();
                 */
            } else {
                throw new Exception("unsupported xpath return type [" + xobj.getClass().getName() + "]");
            }
        } catch (final Exception e) {
            log.error("unkown error occured", e);
        }
    }
}