edu.lternet.pasta.dml.util.DocumentDownloadUtil.java Source code

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Here is the source code for edu.lternet.pasta.dml.util.DocumentDownloadUtil.java

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/**
 *    '$RCSfile: DocumentDataPackageHandler.java,v $'
 *
 *     '$Author: leinfelder $'
 *       '$Date: 2011-02-24 18:06:24 -0700 (Thu, 24 Feb 2011) $'
 *   '$Revision: 2166 $'
 *
 *  For Details: http://ecoinformatics.org
 *
 * Copyright (c) 2008 The Regents of the University of California.
 * All rights reserved.
 * 
 * Permission is hereby granted, without written agreement and without
 * license or royalty fees, to use, copy, modify, and distribute this
 * software and its documentation for any purpose, provided that the
 * above copyright notice and the following two paragraphs appear in
 * all copies of this software.
 * 
 * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
 * FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
 * IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 * 
 * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
 * PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY
 * OF CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT,
 * UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 */
package edu.lternet.pasta.dml.util;

import java.io.IOException;
import java.io.InputStream;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
import java.net.URL;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import edu.lternet.pasta.dml.download.AuthenticatedEcogridEndPointInterface;
import edu.lternet.pasta.dml.download.EcogridEndPointInterface;
import org.ecoinformatics.ecogrid.authenticatedqueryservice.AuthenticatedQueryServiceGetToStreamClient;
import org.ecoinformatics.ecogrid.queryservice.QueryServiceGetToStreamClient;

public class DocumentDownloadUtil {

    public static Log log = LogFactory.getLog(DocumentDownloadUtil.class);

    private PipedInputStream inputStream = null;
    private PipedOutputStream outputStream = null;

    private void init() {
        //initialize the streams for reading the document from server
        outputStream = new PipedOutputStream();
        inputStream = new PipedInputStream();

        try {
            outputStream.connect(inputStream);
        } catch (IOException e1) {
            log.error("could not connect piped streams! " + e1.getMessage());
            e1.printStackTrace();
        }
    }

    public InputStream downloadDocument(final String id, final EcogridEndPointInterface endpoint) throws Exception {

        init();

        log.debug("starting the download");

        ExecutorService service = Executors.newSingleThreadExecutor();
        service.execute(new Runnable() {
            public void run() {
                long startTime = System.currentTimeMillis();

                try {
                    if (endpoint instanceof AuthenticatedEcogridEndPointInterface) {
                        AuthenticatedQueryServiceGetToStreamClient authenticatedEcogridClient = new AuthenticatedQueryServiceGetToStreamClient(
                                new URL(((AuthenticatedEcogridEndPointInterface) endpoint)
                                        .getMetacatAuthenticatedEcogridEndPoint()));
                        authenticatedEcogridClient.get(id,
                                ((AuthenticatedEcogridEndPointInterface) endpoint).getSessionId(), outputStream);
                    } else {
                        QueryServiceGetToStreamClient ecogridClient = new QueryServiceGetToStreamClient(
                                new URL(endpoint.getMetacatEcogridEndPoint()));
                        ecogridClient.get(id, outputStream);
                    }
                    outputStream.close();

                    long endTime = System.currentTimeMillis();
                    log.debug((endTime - startTime) + " ms to download document data");

                    log.debug("Done downloading id=" + id);

                } catch (Exception e) {
                    log.error("Error getting document from ecogrid: " + e.getMessage());
                    e.printStackTrace();
                }

            }
        });

        //wait for the download to complete
        service.shutdown();
        service.awaitTermination(0, TimeUnit.SECONDS);

        log.debug("done with the download");

        return inputStream;

    }

}