ca.nrc.cadc.vosi.avail.CheckWebService.java Source code

Java tutorial

Introduction

Here is the source code for ca.nrc.cadc.vosi.avail.CheckWebService.java

Source

/*
************************************************************************
*******************  CANADIAN ASTRONOMY DATA CENTRE  *******************
**************  CENTRE CANADIEN DE DONNES ASTRONOMIQUES  **************
*
*  (c) 2009.                            (c) 2009.
*  Government of Canada                 Gouvernement du Canada
*  National Research Council            Conseil national de recherches
*  Ottawa, Canada, K1A 0R6              Ottawa, Canada, K1A 0R6
*  All rights reserved                  Tous droits rservs
*                                       
*  NRC disclaims any warranties,        Le CNRC dnie toute garantie
*  expressed, implied, or               nonce, implicite ou lgale,
*  statutory, of any kind with          de quelque nature que ce
*  respect to the software,             soit, concernant le logiciel,
*  including without limitation         y compris sans restriction
*  any warranty of merchantability      toute garantie de valeur
*  or fitness for a particular          marchande ou de pertinence
*  purpose. NRC shall not be            pour un usage particulier.
*  liable in any event for any          Le CNRC ne pourra en aucun cas
*  damages, whether direct or           tre tenu responsable de tout
*  indirect, special or general,        dommage, direct ou indirect,
*  consequential or incidental,         particulier ou gnral,
*  arising from the use of the          accessoire ou fortuit, rsultant
*  software.  Neither the name          de l'utilisation du logiciel. Ni
*  of the National Research             le nom du Conseil National de
*  Council of Canada nor the            Recherches du Canada ni les noms
*  names of its contributors may        de ses  participants ne peuvent
*  be used to endorse or promote        tre utiliss pour approuver ou
*  products derived from this           promouvoir les produits drivs
*  software without specific prior      de ce logiciel sans autorisation
*  written permission.                  pralable et particulire
*                                       par crit.
*                                       
*  This file is part of the             Ce fichier fait partie du projet
*  OpenCADC project.                    OpenCADC.
*                                       
*  OpenCADC is free software:           OpenCADC est un logiciel libre ;
*  you can redistribute it and/or       vous pouvez le redistribuer ou le
*  modify it under the terms of         modifier suivant les termes de
*  the GNU Affero General Public        la GNU Affero General Public
*  License as published by the          License? telle que publie
*  Free Software Foundation,            par la Free Software Foundation
*  either version 3 of the              : soit la version 3 de cette
*  License, or (at your option)         licence, soit ( votre gr)
*  any later version.                   toute version ultrieure.
*                                       
*  OpenCADC is distributed in the       OpenCADC est distribu
*  hope that it will be useful,         dans lespoir quil vous
*  but WITHOUT ANY WARRANTY;            sera utile, mais SANS AUCUNE
*  without even the implied             GARANTIE : sans mme la garantie
*  warranty of MERCHANTABILITY          implicite de COMMERCIALISABILIT
*  or FITNESS FOR A PARTICULAR          ni dADQUATION  UN OBJECTIF
*  PURPOSE.  See the GNU Affero         PARTICULIER. Consultez la Licence
*  General Public License for           Gnrale Publique GNU Affero
*  more details.                        pour plus de dtails.
*                                       
*  You should have received             Vous devriez avoir reu une
*  a copy of the GNU Affero             copie de la Licence Gnrale
*  General Public License along         Publique GNU Affero avec
*  with OpenCADC.  If not, see          OpenCADC ; si ce nest
*  <http://www.gnu.org/licenses/>.      pas le cas, consultez :
*                                       <http://www.gnu.org/licenses/>.
*
*  $Revision: 4 $
*
************************************************************************
*/

package ca.nrc.cadc.vosi.avail;

import ca.nrc.cadc.vosi.VOSI;
import ca.nrc.cadc.vosi.util.WebGet;
import ca.nrc.cadc.xml.XmlUtil;
import org.apache.log4j.Logger;
import org.jdom2.Document;
import org.jdom2.Element;
import org.jdom2.JDOMException;
import org.jdom2.Namespace;
import org.jdom2.filter.Filters;
import org.jdom2.xpath.XPathBuilder;
import org.jdom2.xpath.XPathExpression;
import org.jdom2.xpath.XPathFactory;

import java.io.IOException;
import java.io.StringReader;
import java.net.MalformedURLException;
import java.util.HashMap;
import java.util.Map;

/**
 * Check the /availability resource of another web service.
 * 
 * @author zhangsa
 *
 */
public class CheckWebService implements CheckResource {
    private static Logger log = Logger.getLogger(CheckWebService.class);

    private Map<String, String> schemaMap = new HashMap<String, String>();
    private String wsURL;

    /**
     * @param url the URL of availability checking, e.g. http://www.sample.com/myservice/availability
     */
    public CheckWebService(String url) {
        wsURL = url;
        this.schemaMap.put(VOSI.AVAILABILITY_NS_URI,
                XmlUtil.getResourceUrlString(VOSI.AVAILABILITY_SCHEMA, CheckWebService.class));
    }

    /* (non-Javadoc)
     * @see java.lang.Runnable#run()
     */
    @Override
    public void check() throws CheckException {
        String wgReturn = null;
        try {
            WebGet webGet = new WebGet(wsURL);
            wgReturn = webGet.submit();
            checkReturnedXml(wgReturn);
            log.debug("test succeeded: " + wsURL);
        } catch (MalformedURLException e) {
            log.warn("test failed: " + wsURL);
            throw new RuntimeException("test URL is malformed: " + wsURL, e);
        } catch (IOException e) {
            log.warn("test failed: " + wsURL);
            throw new CheckException("service not responding: " + wsURL, e);
        }
    }

    void checkReturnedXml(String strXml) throws CheckException {
        Document doc;
        String xpathStr;

        try {
            StringReader reader = new StringReader(strXml);
            doc = XmlUtil.buildDocument(reader, schemaMap);

            //get namespace and/or prefix from Document, then create xpath based on the prefix
            String nsp = doc.getRootElement().getNamespacePrefix(); //Namespace Prefix
            if (nsp != null && nsp.length() > 0)
                nsp = nsp + ":";
            else
                nsp = "";
            xpathStr = "/" + nsp + "availability/" + nsp + "available";
            XPathBuilder<Element> builder = new XPathBuilder<Element>(xpathStr, Filters.element());
            Namespace ns = Namespace.getNamespace(VOSI.NS_PREFIX, VOSI.AVAILABILITY_NS_URI);
            builder.setNamespace(ns);
            XPathExpression<Element> xpath = builder.compileWith(XPathFactory.instance());
            Element eleAvail = xpath.evaluateFirst(doc);
            log.debug(eleAvail);
            String textAvail = eleAvail.getText();

            // TODO: is this is actually valid? is the content not constrained by the schema?
            if (textAvail == null)
                throw new CheckException(wsURL + " output is invalid: no content in <available> element", null);

            if (!textAvail.equalsIgnoreCase("true")) {
                xpathStr = "/" + nsp + "availability/" + nsp + "note";
                builder = new XPathBuilder<Element>(xpathStr, Filters.element());
                builder.setNamespace(ns);
                xpath = builder.compileWith(XPathFactory.instance());
                Element eleNotes = xpath.evaluateFirst(doc);

                String textNotes = eleNotes.getText();
                throw new CheckException("service " + wsURL + " is not available, reported reason: " + textNotes,
                        null);
            }
        } catch (IOException e) {
            // probably an incorrect setup or bug in the checks
            throw new RuntimeException("failed to test " + wsURL, e);
        } catch (JDOMException e) {
            throw new CheckException(wsURL + " output is invalid", e);
        }
    }

}