com.mebigfatguy.polycasso.URLFetcher.java Source code

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Here is the source code for com.mebigfatguy.polycasso.URLFetcher.java

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/*
 * polycasso - Cubism Artwork generator
 * Copyright 2009-2015 MeBigFatGuy.com
 * Copyright 2009-2015 Dave Brosius
 * Inspired by work by Roger Alsing
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *    http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and limitations
 * under the License.
 */
package com.mebigfatguy.polycasso;

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.InetSocketAddress;
import java.net.Proxy;
import java.net.Proxy.Type;
import java.net.URL;

import org.apache.commons.io.IOUtils;

/**
 * manages downloading data from a url
 */
public class URLFetcher {

    /**
     * private to avoid construction of this static access only class
     */
    private URLFetcher() {
    }

    /**
     * retrieve arbitrary data found at a specific url
     * - either http or file urls
     * for http requests, sets the user-agent to mozilla to avoid
     * sites being cranky about a java sniffer
     * 
     * @param url the url to retrieve
     * @param proxyHost the host to use for the proxy
     * @param proxyPort the port to use for the proxy
     * @return a byte array of the content
     * 
     * @throws IOException the site fails to respond
     */
    public static byte[] fetchURLData(String url, String proxyHost, int proxyPort) throws IOException {
        HttpURLConnection con = null;
        InputStream is = null;

        try {
            URL u = new URL(url);
            if (url.startsWith("file://")) {
                is = new BufferedInputStream(u.openStream());
            } else {
                Proxy proxy;
                if (proxyHost != null) {
                    proxy = new Proxy(Type.HTTP, new InetSocketAddress(proxyHost, proxyPort));
                } else {
                    proxy = Proxy.NO_PROXY;
                }
                con = (HttpURLConnection) u.openConnection(proxy);
                con.addRequestProperty("User-Agent",
                        "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/536.6 (KHTML, like Gecko) Chrome/20.0.1092.0 Safari/536.6");
                con.addRequestProperty("Accept-Charset", "UTF-8");
                con.addRequestProperty("Accept-Language", "en-US,en");
                con.addRequestProperty("Accept", "text/html,image/*");
                con.setDoInput(true);
                con.setDoOutput(false);
                con.connect();

                is = new BufferedInputStream(con.getInputStream());
            }

            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            IOUtils.copy(is, baos);
            return baos.toByteArray();
        } finally {
            IOUtils.closeQuietly(is);
            if (con != null) {
                con.disconnect();
            }
        }
    }
}