/*
* Copyright (c) 2010 Lockheed Martin Corporation
*
* 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 org.eurekastreams.server.service.utility.http;
import java.io.IOException;
import java.util.Map;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.apache.commons.httpclient.DefaultHttpMethodRetryHandler;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpConnectionManager;
import org.apache.commons.httpclient.HttpMethodRetryHandler;
import org.apache.commons.httpclient.SimpleHttpConnectionManager;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.params.HttpClientParams;
import org.apache.commons.httpclient.params.HttpConnectionManagerParams;
import org.apache.commons.httpclient.params.HttpMethodParams;
import org.w3c.dom.Document;
import org.xml.sax.SAXException;
/**
* Gets a URL resource and returns it as an XML document.
*/
public class HttpDocumentFetcherImpl implements HttpDocumentFetcher
{
/**
* Retrieves an XML document from a given URL.
*
* @param url
* The URL from which to get the document.
* @param httpHeaders
* HTTP headers to add to the request.
* @param proxyHost
* host name to use (if desired) for proxying http requests.
* @param proxyPort
* port for http proxy server.
* @param timeout
* the timeout period to wait for the request to return (in ms).
* @param domFactory
* Factory for creating document builders.
* @return The document.
* @throws IOException
* On error.
* @throws ParserConfigurationException
* On error.
* @throws SAXException
* On error.
*/
public Document fetchDocument(final String url, final Map<String, String> httpHeaders, final String proxyHost,
final String proxyPort, final int timeout, final DocumentBuilderFactory domFactory) throws IOException,
ParserConfigurationException, SAXException
{
HttpConnectionManagerParams managerParams = new HttpConnectionManagerParams();
managerParams.setSoTimeout(timeout);
managerParams.setConnectionTimeout(timeout);
HttpConnectionManager manager = new SimpleHttpConnectionManager();
manager.setParams(managerParams);
HttpClientParams params = new HttpClientParams();
params.setConnectionManagerTimeout(timeout);
params.setSoTimeout(timeout);
HttpClient client = new HttpClient(params, manager);
HttpMethodRetryHandler retryHandler = new DefaultHttpMethodRetryHandler(1, true);
client.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, retryHandler);
if (!proxyHost.isEmpty())
{
client.getHostConfiguration().setProxy(proxyHost, Integer.parseInt(proxyPort));
}
GetMethod get = new GetMethod(url);
if (httpHeaders != null)
{
for (Map.Entry<String, String> header : httpHeaders.entrySet())
{
get.setRequestHeader(header.getKey(), header.getValue());
}
}
try
{
client.executeMethod(get);
DocumentBuilder builder = domFactory.newDocumentBuilder();
return builder.parse(get.getResponseBodyAsStream());
}
finally
{
get.releaseConnection();
}
}
}