de.innovationgate.webgate.api.query.rss.WGResultSetImpl.java Source code

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Here is the source code for de.innovationgate.webgate.api.query.rss.WGResultSetImpl.java

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/*******************************************************************************
 * Copyright 2009, 2010 Innovation Gate GmbH. All Rights Reserved.
 * 
 * This file is part of the OpenWGA server platform.
 * 
 * OpenWGA is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * In addition, a special exception is granted by the copyright holders
 * of OpenWGA called "OpenWGA plugin exception". You should have received
 * a copy of this exception along with OpenWGA in file COPYING.
 * If not, see <http://www.openwga.com/gpl-plugin-exception>.
 * 
 * OpenWGA is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with OpenWGA in file COPYING.
 * If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
package de.innovationgate.webgate.api.query.rss;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.dom4j.Element;
import org.dom4j.Namespace;
import org.dom4j.QName;

import de.innovationgate.webgate.api.WGDatabase;
import de.innovationgate.webgate.api.WGDocumentCore;
import de.innovationgate.webgate.api.WGResultSetCore;

public class WGResultSetImpl implements WGResultSetCore {

    public static final String NS_RSS1_NETSCAPE = "http://my.netscape.com/rdf/simple/0.9/";
    public static final String NS_RSS1_PURL = "http://purl.org/rss/1.0/";

    private String instantiation;
    private WGDatabase db;
    private org.dom4j.Document doc;
    private List itemsList = null;
    private Element channel = null;
    private boolean isRSS1 = false;

    public WGResultSetImpl(WGDatabase db, org.dom4j.Document doc) {
        this.instantiation = new Long(System.currentTimeMillis()).toString();
        this.db = db;
        this.doc = doc;

        if (this.doc.getRootElement().getName().equalsIgnoreCase("RDF")) {
            isRSS1 = true;
        }
    }

    /**
     * @see de.innovationgate.webgate.api.WGResultSetCore#getContentList()
     */
    public List getContentList() {

        Iterator itemElements = this.getItemsList().iterator();
        List items = new ArrayList();
        int counter = 0;
        String key;
        while (itemElements.hasNext()) {
            key = instantiation + "_" + counter++;
            items.add(new WGDocumentImpl(db, key, this.getChannel(), (Element) itemElements.next()));
        }
        return items;

    }

    /**
     * @see de.innovationgate.webgate.api.WGResultSetCore#getContentList(int, int)
     */
    public List getContentList(int start, int length) {

        Iterator itemElements = this.getItemsList().subList(start, start + length).iterator();
        List items = new ArrayList();
        int counter = start;
        String key;
        while (itemElements.hasNext()) {
            key = instantiation + "_" + counter++;
            items.add(createDocumentImpl((Element) itemElements.next(), key));
        }
        return items;

    }

    public WGDocumentCore createDocumentImpl(Element element, String key) {
        if (isRSS1) {
            return new WGDocumentImplRSS1(db, key, this.getChannel(), element);
        } else {
            return new WGDocumentImpl(db, key, this.getChannel(), element);
        }
    }

    /**
     * @see de.innovationgate.webgate.api.WGResultSetCore#results()
     */
    public int results() {
        return this.getItemsList().size();
    }

    private List getItemsList() {

        if (this.itemsList == null) {

            if (isRSS1) {
                this.itemsList = this.doc.getRootElement().elements(new QName("item", Namespace.get(NS_RSS1_PURL)));
                if (this.itemsList.size() == 0) {
                    this.itemsList = this.doc.getRootElement()
                            .elements(new QName("item", Namespace.get(NS_RSS1_NETSCAPE)));
                }
            } else {
                this.itemsList = this.doc.selectNodes("//item");
            }
        }
        return this.itemsList;

    }

    private Element getChannel() {

        if (this.channel == null) {
            if (isRSS1) {
                this.channel = (Element) this.doc.getRootElement()
                        .element(new QName("channel", Namespace.get(NS_RSS1_PURL)));
                if (this.channel == null) {
                    this.channel = (Element) this.doc.getRootElement()
                            .element(new QName("channel", Namespace.get(NS_RSS1_NETSCAPE)));
                }
            } else {
                this.channel = (Element) this.doc.selectSingleNode("//channel");
            }
        }
        return this.channel;
    }

    public boolean isReturnsKeys() {
        return false;
    }

    public List getColumnNames() {
        return null;
    }

    public boolean isLimitingResults() {
        return false;
    }

}