netinf.node.transferdispatcher.streamprovider.HTTPStreamProvider.java Source code

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Here is the source code for netinf.node.transferdispatcher.streamprovider.HTTPStreamProvider.java

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/*
 * Copyright (C) 2009-2011 University of Paderborn, Computer Networks Group
 * (Full list of owners see http://www.netinf.org/about-2/license)
 * 
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
 * 
 *     * Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright notice,
 *       this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
 *     * Neither the name of the University of Paderborn nor the names of its contributors may be used to endorse
 *       or promote products derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package netinf.node.transferdispatcher.streamprovider;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;

import netinf.common.utils.Utils;
import netinf.node.chunking.Chunk;

import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.log4j.Logger;

/**
 * StreamProvider for HTTP protocol
 * 
 * @author PG NetInf 3, University of Paderborn.
 */
public class HTTPStreamProvider implements StreamProvider {
    private static final Logger LOG = Logger.getLogger(HTTPStreamProvider.class);
    private String providerName = "HTTP Streamprovider";

    @Override
    public InputStream getStream(String url) throws IOException {
        URL conn = new URL(url);
        return conn.openStream();
    }

    @Override
    public InputStream getStream(Chunk chunk, String chunkUrl) throws IOException {
        // determine range
        int chunkSizeInBytes = 256 * 1024;
        int from = chunkSizeInBytes * chunk.getNumber();
        int to = (chunkSizeInBytes * (chunk.getNumber() + 1)) - 1;

        HttpClient client = new DefaultHttpClient();
        HttpGet httpGet = new HttpGet(chunkUrl);
        httpGet.setHeader("Range", "bytes=" + from + "-" + to);
        try {
            HttpResponse response = client.execute(httpGet);
            int status = response.getStatusLine().getStatusCode();
            if (status == HttpStatus.SC_PARTIAL_CONTENT) {

                InputStream inStream = response.getEntity().getContent();
                // check integrity
                String destination = Utils.getTmpFolder("chunkproviding") + File.separator + chunk.getHash()
                        + ".tmp";
                boolean success = Utils.saveTemp(inStream, destination);

                if (success) {
                    if (Utils.isValidHash(chunk.getHash(), destination)) {
                        return new FileInputStream(destination);
                    } else {
                        throw new IOException("Hash of chunk no. " + chunk.getNumber() + " is NOT valid...");
                    }
                }

            } else {
                throw new IOException("Error at ranges request... status: " + status);
            }
        } catch (ClientProtocolException e) {
            throw new IOException("Error at ranges request...");
        } catch (IOException e) {
            throw new IOException("Error at ranges request...: ");
        }

        return new InputStream() {
            @Override
            public int read() throws IOException {
                LOG.warn("(HTTPStreamProvider ) returning an error stream (-1)");
                return -1;
            }
        };
    }

    @Override
    public boolean canHandle(String url) {
        if (url.startsWith("http://")) {
            return true;
        }
        return false;
    }

    @Override
    public String describe() {
        return providerName;
    }

}