com.carrotsearch.util.httpclient.HttpUtils.java Source code

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Here is the source code for com.carrotsearch.util.httpclient.HttpUtils.java

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/*
 * Carrot2 project.
 *
 * Copyright (C) 2002-2008, Dawid Weiss, Stanisaw Osiski.
 * Portions (C) Contributors listed in "carrot2.CONTRIBUTORS" file.
 * 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 com.carrotsearch.util.httpclient;

import java.io.*;
import java.util.Collection;
import java.util.zip.GZIPInputStream;

import org.apache.commons.httpclient.*;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.log4j.Logger;

import com.carrotsearch.util.StreamUtils;

/**
 * Various utilities for working with HTTP data streams.
 */
public class HttpUtils {
    /**
     * A static holder storing HTTP response fields.
     */
    public final static class Response {
        public byte[] payload;
        public int status;
        public String compression;
        public String[][] headers;

        public InputStream getPayloadAsStream() {
            return new ByteArrayInputStream(payload);
        }
    }

    /**
     * GZIP compression was used.
     * 
     * @see HttpUtils.Response#compression
     */
    private static final String COMPRESSION_GZIP = "gzip";

    /**
     * No compression was used.
     * 
     * @see HttpUtils.Response#compression
     */
    private static final String COMPRESSION_NONE = "uncompressed";

    /*
     * 
     */
    private HttpUtils() {
        // No instances.
    }

    /**
     * Opens a HTTP/1.1 connection to the given URL using the GET method, decompresses
     * compressed response streams, if supported by the server.
     * 
     * @param url The URL to open. The URL must be properly escaped, this method will
     *            <b>not</b> perform any escaping.
     * @param params Query string parameters to be attached to the url.
     * @param headers Any extra HTTP headers to add to the request.
     * @return The {@link HttpUtils.Response} object. Note that entire payload is read and
     *         buffered so that the HTTP connection can be closed when leaving this
     *         method.
     */
    public static Response doGET(String url, Collection<NameValuePair> params, Collection<Header> headers)
            throws HttpException, IOException {
        final HttpClient client = HttpClientFactory.getTimeoutingClient();
        client.getParams().setVersion(HttpVersion.HTTP_1_1);

        final GetMethod request = new GetMethod();
        final Response response = new Response();
        try {
            request.setURI(new URI(url, true));

            if (params != null) {
                request.setQueryString(params.toArray(new NameValuePair[params.size()]));
            }

            request.setRequestHeader(HttpHeaders.URL_ENCODED);
            request.setRequestHeader(HttpHeaders.GZIP_ENCODING);
            if (headers != null) {
                for (Header header : headers)
                    request.setRequestHeader(header);
            }

            Logger.getLogger(HttpUtils.class).debug("GET: " + request.getURI());

            final int statusCode = client.executeMethod(request);
            response.status = statusCode;

            InputStream stream = request.getResponseBodyAsStream();
            final Header encoded = request.getResponseHeader("Content-Encoding");
            if (encoded != null && "gzip".equalsIgnoreCase(encoded.getValue())) {
                stream = new GZIPInputStream(stream);
                response.compression = COMPRESSION_GZIP;
            } else {
                response.compression = COMPRESSION_NONE;
            }

            final Header[] respHeaders = request.getResponseHeaders();
            response.headers = new String[respHeaders.length][];
            for (int i = 0; i < respHeaders.length; i++) {
                response.headers[i] = new String[] { respHeaders[i].getName(), respHeaders[i].getValue() };
            }

            response.payload = StreamUtils.readFullyAndClose(stream);
            return response;
        } finally {
            request.releaseConnection();
        }
    }
}