org.bibsonomy.rest.client.worker.impl.GetWorker.java Source code

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Here is the source code for org.bibsonomy.rest.client.worker.impl.GetWorker.java

Source

/**
 *
 *  BibSonomy-Rest-Client - The REST-client.
 *
 *  Copyright (C) 2006 - 2011 Knowledge & Data Engineering Group,
 *                            University of Kassel, Germany
 *                            http://www.kde.cs.uni-kassel.de/
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public License
 *  as published by the Free Software Foundation; either version 2
 *  of the License, or (at your option) any later version.
 *
 *  This program 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

package org.bibsonomy.rest.client.worker.impl;

import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringReader;

import org.apache.commons.httpclient.methods.GetMethod;
import org.bibsonomy.rest.client.ProgressCallback;
import org.bibsonomy.rest.client.exception.ErrorPerformingRequestException;
import org.bibsonomy.rest.client.worker.HttpWorker;
import org.bibsonomy.rest.utils.HeaderUtils;

/**
 * @author Manuel Bork <manuel.bork@uni-kassel.de>
 * @version $Id: GetWorker.java,v 1.14 2011-05-24 09:47:34 bibsonomy Exp $
 */
public final class GetWorker extends HttpWorker<GetMethod> {

    private final ProgressCallback callback;

    /**
     * 
     * @param username   the username
     * @param password   the password (apiKey)
     * @param callback   the callback
     */
    public GetWorker(final String username, final String password, final ProgressCallback callback) {
        super(username, password);

        this.callback = callback;
    }

    @Override
    protected GetMethod getMethod(String url, String requestBody) {
        final GetMethod get = new GetMethod(url);
        get.setFollowRedirects(true);
        return get;
    }

    @Override
    protected Reader readResponse(GetMethod method) throws IOException, ErrorPerformingRequestException {
        if (method.getResponseBodyAsStream() != null) {
            return performDownload(method.getResponseBodyAsStream(), method.getResponseContentLength());
        }

        throw new ErrorPerformingRequestException("No Answer.");
    }

    private Reader performDownload(final InputStream responseBodyAsStream, final long responseContentLength)
            throws ErrorPerformingRequestException, IOException {
        if (responseContentLength > Integer.MAX_VALUE)
            throw new ErrorPerformingRequestException("The response is to long: " + responseContentLength);

        final StringBuilder sb = new StringBuilder((int) responseContentLength);
        final BufferedReader br = new BufferedReader(new InputStreamReader(responseBodyAsStream, "UTF-8"));
        int bytesRead = 0;
        String line = null;
        while ((line = br.readLine()) != null) {
            bytesRead += line.length();
            callCallback(bytesRead, responseContentLength);
            sb.append(line);
        }

        return new StringReader(sb.toString());
    }

    /**
     * Download the file
     * @param url
     * @param file
     * @throws ErrorPerformingRequestException
     * @author Waldemar Biller
     */
    public void performFileDownload(final String url, File file) throws ErrorPerformingRequestException {

        LOGGER.debug("GET: URL: " + url);

        // dirty but working
        if (this.proxyHost != null) {
            getHttpClient().getHostConfiguration().setProxy(this.proxyHost, this.proxyPort);
        }

        final GetMethod get = new GetMethod(url);
        get.addRequestHeader(HeaderUtils.HEADER_AUTHORIZATION,
                HeaderUtils.encodeForAuthorization(this.username, this.apiKey));
        get.setDoAuthentication(true);
        get.setFollowRedirects(true);

        try {
            this.httpResult = getHttpClient().executeMethod(get);
            LOGGER.debug("HTTP result: " + this.httpResult);
            LOGGER.debug("Content-Type:" + get.getRequestHeaders("Content-Type"));
            LOGGER.debug("===================================================");
            final InputStream in = get.getResponseBodyAsStream();

            /*
             * FIXME: check for errors
             */
            if (in != null) {

                // read the file from the source and write it to 
                // the target given by the file parametetr

                final DataOutputStream dos = new DataOutputStream(
                        new BufferedOutputStream(new FileOutputStream(file)));

                int bytesRead = 0;
                int b = 0;
                do {
                    b = in.read();
                    dos.write(b);
                    callCallback(bytesRead++, get.getResponseContentLength());
                } while (b > -1);

                in.close();
                dos.close();

                return;
            }
        } catch (final IOException e) {
            LOGGER.debug(e.getMessage(), e);
            throw new ErrorPerformingRequestException(e);
        } finally {
            get.releaseConnection();
        }
        throw new ErrorPerformingRequestException("No Answer.");
    }

    private void callCallback(final int bytesRead, final long responseContentLength) {
        if (this.callback != null && responseContentLength > 0) {
            this.callback.setPercent((int) (bytesRead * 100 / responseContentLength));
        }
    }
}