org.eclipse.smila.search.lucene.messages.indexstructure.DParameterCodec.java Source code

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Here is the source code for org.eclipse.smila.search.lucene.messages.indexstructure.DParameterCodec.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: August Georg Schmidt (brox IT Solutions GmbH) - initial API and implementation
 **********************************************************************************************************************/
package org.eclipse.smila.search.lucene.messages.indexstructure;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;

/**
 * @author gschmidt
 * 
 */
public abstract class DParameterCodec {

    /**
     * Constructor.
     */
    private DParameterCodec() {

    }

    /**
     * @param dParameter -
     * @param parent -
     * @return Element
     */
    public static Element encode(DParameter dParameter, Element parent) {
        // prepare
        final Document doc = parent.getOwnerDocument();
        final Element me = (Element) parent.appendChild(doc.createElementNS(DIndexStructureCodec.NS, "Parameter"));

        Element child = null;

        child = (Element) me.appendChild(doc.createElementNS(DIndexStructureCodec.NS, "Name"));
        child.appendChild(doc.createTextNode(dParameter.getName()));
        child = (Element) me.appendChild(doc.createElementNS(DIndexStructureCodec.NS, "Value"));
        child.appendChild(doc.createTextNode(dParameter.getValue()));

        return me;
    }

    /**
     * @param element -
     * @return DParameter
     */
    public static DParameter decode(Element element) {
        final Log log = LogFactory.getLog(DParameterCodec.class);
        String paramName = null;
        String paramValue = null;
        // decode Term
        final NodeList nl = element.getChildNodes();
        for (int i = 0; i < nl.getLength(); i++) {
            /*
             * if (log.isInfoEnabled()) { log.info("DParameterCodec: node " + nl.item(i)); }
             */
            if ("Name".equals(nl.item(i).getLocalName())) {
                paramName = ((Text) nl.item(i).getFirstChild()).getData().trim();
            }

            if ("Value".equals(nl.item(i).getLocalName())) {
                final NamedNodeMap attrs = nl.item(i).getAttributes();
                final Node nilItem = (attrs == null) ? null : attrs.getNamedItem("xsi:nil");
                final String xsiNil = (nilItem == null) ? null : nilItem.getNodeValue();
                final boolean isNil = (xsiNil != null)
                        && (xsiNil.toLowerCase().equals("true") || xsiNil.equals("1"));
                if (isNil) {
                    paramValue = null;
                } else {
                    paramValue = ((Text) nl.item(i).getFirstChild()).getData().trim();
                }
            }

        }

        final DParameter dParameter = new DParameter(paramName, paramValue);
        return dParameter;
    }

}