com.k42b3.neodym.Services.java Source code

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Here is the source code for com.k42b3.neodym.Services.java

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/**
 * $Id$
 * 
 * neodym
 * A java library to access the REST API of amun
 * 
 * Copyright (c) 2011 Christoph Kappestein <k42b3.x@gmail.com>
 * 
 * This file is part of neodym. neodym 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 any later version.
 * 
 * neodym 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 neodym. If not, see <http://www.gnu.org/licenses/>.
 */

package com.k42b3.neodym;

import java.util.ArrayList;
import java.util.logging.Logger;

import org.apache.http.Header;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * Contains all discovered items of the XRDS
 *
 * @author     Christoph Kappestein <k42b3.x@gmail.com>
 * @license    http://www.gnu.org/licenses/gpl.html GPLv3
 * @link       http://code.google.com/p/delta-quadrant
 * @version    $Revision$
 */
public class Services {
    private String baseUrl;
    private Http http;

    private ArrayList<ServiceItem> services = new ArrayList<ServiceItem>();

    private Logger logger = Logger.getLogger("com.k42b3.neodym");

    public Services(Http http, String baseUrl) {
        this.baseUrl = baseUrl;
        this.http = http;
    }

    public void discover() throws Exception {
        String url = this.getXrdsUrl(baseUrl);

        if (url != null) {
            this.request(url);
        } else {
            throw new Exception("Could not find xrds location");
        }
    }

    public ServiceItem getElementAt(int index) {
        return services.get(index);
    }

    public int getSize() {
        return services.size();
    }

    public ServiceItem getItem(String type) {
        for (int i = 0; i < services.size(); i++) {
            if (services.get(i).hasType(type)) {
                return services.get(i);
            }
        }

        return null;
    }

    private String getXrdsUrl(String url) throws Exception {
        http.request(Http.GET, url, null, null, false);

        // find x-xrds-location header
        Header[] headers = http.getLastResponse().getAllHeaders();
        String xrdsLocation = null;

        for (int i = 0; i < headers.length; i++) {
            if (headers[i].getName().toLowerCase().equals("x-xrds-location")) {
                xrdsLocation = headers[i].getValue();

                logger.info("Found XRDS location: " + xrdsLocation);

                break;
            }
        }

        return xrdsLocation;
    }

    private void request(String url) throws Exception {
        // request
        Document doc = http.requestXml(Http.GET, url);

        // parse services
        NodeList serviceList = doc.getElementsByTagName("Service");

        for (int i = 0; i < serviceList.getLength(); i++) {
            Node serviceNode = serviceList.item(i);
            Element serviceElement = (Element) serviceNode;

            NodeList typeElementList = serviceElement.getElementsByTagName("Type");
            Element uriElement = (Element) serviceElement.getElementsByTagName("URI").item(0);

            if (typeElementList.getLength() > 0 && uriElement != null) {
                ArrayList<String> types = new ArrayList<String>();

                for (int j = 0; j < typeElementList.getLength(); j++) {
                    types.add(typeElementList.item(j).getTextContent());
                }

                String uri = uriElement.getTextContent();

                services.add(new ServiceItem(uri, types));
            }
        }

        logger.info("Found " + services.size() + " services");
    }
}