HttpClientFactory.java

/*
 * Carrot2 project.
 *
 * Copyright (C) 2002-2016, Dawid Weiss, Stanisław Osiński.
 * All rights reserved.
 *
 * Refer to the full license file "carrot2.LICENSE"
 * in the root folder of the repository checkout or at:
 * http://www.carrot2.org/carrot2.LICENSE
 */

package org.carrot2.util.httpclient;

import org.apache.commons.lang.StringUtils;
import org.apache.http.HttpHost;
import org.apache.http.client.HttpClient;
import org.apache.http.conn.params.ConnRoutePNames;
import org.apache.http.impl.NoConnectionReuseStrategy;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.CoreConnectionPNames;

/**
 * Prepare instances of {@link HttpClient} with desired socket configuration settings.
 * This class takes into account two legacy Java properties:
 * <ul>
 * <li>http.proxyhost</li>
 * <li>http.proxyport</li>
 * </ul>
 * These properties configure HTTP proxy through which all requests are tunneled (there is
 * no need to configure per-connection proxy). No custom proxy authorization methods are
 * implemented as of yet.
 */
@SuppressWarnings("deprecation")
public final class HttpClientFactory
{
    private static final String PROPERTY_NAME_PROXY_HOST = "http.proxyhost";
    private static final String PROPERTY_NAME_PROXY_PORT = "http.proxyport";

    /**
     * Default timeout for {@link #getTimeoutingClient()} in milliseconds.
     */
    public static final int DEFAULT_TIMEOUT = 8 * 1000;

    /*
     * 
     */
    private HttpClientFactory()
    {
        // no instances
    }

    /**
     * @param timeout Timeout in milliseconds.
     * @return Returns a client with sockets configured to timeout after some sensible
     *         time.
     */
    public static DefaultHttpClient getTimeoutingClient(int timeout)
    {
        final DefaultHttpClient httpClient = new DefaultHttpClient();

        configureProxy(httpClient);

        // Setup defaults.
        httpClient.setReuseStrategy(new NoConnectionReuseStrategy());

        httpClient.getParams().setIntParameter(CoreConnectionPNames.SO_TIMEOUT, timeout);
        httpClient.getParams().setIntParameter(CoreConnectionPNames.CONNECTION_TIMEOUT, timeout);
        httpClient.getParams().setIntParameter(CoreConnectionPNames.SO_LINGER, 0);

        return httpClient;
    }

    /**
     * Configure HTTP proxy from system properties, if available.
     */
    private static void configureProxy(HttpClient httpClient)
    {
        final String proxyHost = System.getProperty(PROPERTY_NAME_PROXY_HOST);
        final String proxyPort = System.getProperty(PROPERTY_NAME_PROXY_PORT);
        
        if (!StringUtils.isEmpty(proxyHost) && !StringUtils.isEmpty(proxyPort))
        {
            try
            {
                final int port = Integer.parseInt(proxyPort);
                httpClient.getParams().setParameter(
                    ConnRoutePNames.DEFAULT_PROXY, new HttpHost(proxyHost, port));
            }
            catch (NumberFormatException e)
            {
                // Ignore.
            }
        }
    }

    /**
     * @see #getTimeoutingClient(int)
     * @see #DEFAULT_TIMEOUT
     */
    public static HttpClient getTimeoutingClient()
    {
        return getTimeoutingClient(DEFAULT_TIMEOUT);
    }
}