Java tutorial
/* * File: $HeadURL$ * Version: $LastChangedRevision$ * Date: $Date$ * Author: $LastChangedBy$ * * JVoiceXML - A free VoiceXML implementation. * * Copyright (C) 2005-2012 JVoiceXML group - http://jvoicexml.sourceforge.net * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ package org.jvoicexml.documentserver.schemestrategy; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.net.URI; import java.net.URISyntaxException; import java.util.ArrayList; import java.util.Collection; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.HttpStatus; import org.apache.http.NameValuePair; import org.apache.http.StatusLine; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.client.methods.HttpUriRequest; import org.apache.http.client.utils.URIBuilder; import org.apache.http.client.utils.URLEncodedUtils; import org.apache.http.entity.ContentType; import org.apache.http.entity.FileEntity; import org.apache.http.message.BasicNameValuePair; import org.apache.http.params.CoreConnectionPNames; import org.apache.http.params.HttpParams; import org.apache.log4j.Logger; import org.jvoicexml.documentserver.SchemeStrategy; import org.jvoicexml.event.error.BadFetchError; import org.jvoicexml.event.error.SemanticError; import org.jvoicexml.interpreter.datamodel.KeyValuePair; import org.jvoicexml.xml.vxml.RequestMethod; /** * {@link SchemeStrategy} to read VoiceXML document via the HTTP protocol. * * <p> * This implementation uses the proxy settings that are delivered via the * environment variables <code>http.proxyHost</code> and * <code>http.proxyPort</code>. * </p> * * @author Dirk Schnelle-Walka * @version $Revision$ */ public final class HttpSchemeStrategy implements SchemeStrategy { /** Logger for this class. */ private static final Logger LOGGER = Logger.getLogger(HttpSchemeStrategy.class); /** Scheme for which this scheme strategy is responsible. */ public static final String HTTP_SCHEME_NAME = "http"; /** the storage of session identifiers. */ private static final SessionStorage<HttpClient> SESSION_STORAGE; /** Encoding that should be used to encode/decode URLs. */ private static String encoding = System.getProperty("jvoicexml.xml.encoding", "UTF-8"); /** Scheme name for this strategy. */ private String scheme; /** The default fetch timeout. */ private int defaultFetchTimeout; static { final SessionIdentifierFactory<HttpClient> factory = new HttpClientSessionIdentifierFactory(); SESSION_STORAGE = new SessionStorage<HttpClient>(factory); } /** * Construct a new object. */ public HttpSchemeStrategy() { // Initialize with HTTP as default. scheme = HTTP_SCHEME_NAME; } /** * Sets the scheme for this strategy. * * @param value * the new scheme * @since 0.7.4 */ public void setScheme(final String value) { scheme = value; } /** * {@inheritDoc} */ @Override public String getScheme() { return scheme; } /** * Sets the default fetch timeout. * * @param timeout * the default fetch timeout. * @since 0.7 */ public void setFetchTimeout(final int timeout) { if (LOGGER.isDebugEnabled()) { LOGGER.debug("default fetch timeout: " + timeout); } defaultFetchTimeout = timeout; } /** * {@inheritDoc} */ @Override public InputStream getInputStream(final String sessionId, final URI uri, final RequestMethod method, final long timeout, final Collection<KeyValuePair> parameters) throws BadFetchError { final HttpClient client = SESSION_STORAGE.getSessionIdentifier(sessionId); final URI fullUri; try { final URI fragmentLessUri = new URI(uri.getScheme(), uri.getAuthority(), uri.getPath(), uri.getQuery(), null); fullUri = addParameters(parameters, fragmentLessUri); } catch (URISyntaxException e) { throw new BadFetchError(e.getMessage(), e); } catch (SemanticError e) { throw new BadFetchError(e.getMessage(), e); } final String url = fullUri.toString(); if (LOGGER.isDebugEnabled()) { LOGGER.debug("connecting to '" + url + "'..."); } final HttpUriRequest request; if (method == RequestMethod.GET) { request = new HttpGet(url); } else { request = new HttpPost(url); } attachFiles(request, parameters); try { final HttpParams params = client.getParams(); setTimeout(timeout, params); final HttpResponse response = client.execute(request); final StatusLine statusLine = response.getStatusLine(); final int status = statusLine.getStatusCode(); if (status != HttpStatus.SC_OK) { throw new BadFetchError(statusLine.getReasonPhrase() + " (HTTP error code " + status + ")"); } final HttpEntity entity = response.getEntity(); return entity.getContent(); } catch (IOException e) { throw new BadFetchError(e.getMessage(), e); } } /** * Sets the timeout for the current connection. * * @param timeout * timeout as it is declared in the document. * @param params * connection parameters. * @since 0.7 */ private void setTimeout(final long timeout, final HttpParams params) { if (timeout != 0) { params.setParameter(CoreConnectionPNames.CONNECTION_TIMEOUT, new Integer((int) timeout)); if (LOGGER.isDebugEnabled()) { LOGGER.debug("timeout set to '" + timeout + "'"); } } else if (defaultFetchTimeout != 0) { params.setParameter(CoreConnectionPNames.CONNECTION_TIMEOUT, defaultFetchTimeout); if (LOGGER.isDebugEnabled()) { LOGGER.debug("timeout set to default '" + defaultFetchTimeout + "'"); } } } /** * Adds the parameters to the HTTP method. * * @param parameters * parameters to add * @param uri * the given URI * @return URI with the given parameters * @throws URISyntaxException * error creating a URI * @throws SemanticError * error evaluating a parameter */ private URI addParameters(final Collection<KeyValuePair> parameters, final URI uri) throws URISyntaxException, SemanticError { if ((parameters == null) || parameters.isEmpty()) { return uri; } final ArrayList<NameValuePair> queryParameters = new ArrayList<NameValuePair>(); for (KeyValuePair current : parameters) { final Object value = current.getValue(); if (!(value instanceof File)) { final String name = current.getKey(); final NameValuePair pair = new BasicNameValuePair(name, value.toString()); queryParameters.add(pair); } } final Collection<NameValuePair> parameterList = URLEncodedUtils.parse(uri, encoding); queryParameters.addAll(parameterList); final String query = URLEncodedUtils.format(queryParameters, encoding); final URIBuilder builder = new URIBuilder(uri); builder.setQuery(query); return builder.build(); } /** * Attach the files given in the parameters. * * @param request * the current request * @param parameters * the parameters * @since 0.7.3 */ private void attachFiles(final HttpUriRequest request, final Collection<KeyValuePair> parameters) { if (!(request instanceof HttpPost)) { return; } final HttpPost post = (HttpPost) request; for (KeyValuePair current : parameters) { final Object value = current.getValue(); if (value instanceof File) { final File file = (File) value; final FileEntity fileEntity = new FileEntity(file, ContentType.create("binary/octet-stream")); post.setEntity(fileEntity); } } } /** * {@inheritDoc} */ @Override public void sessionClosed(final String sessionId) { SESSION_STORAGE.releaseSession(sessionId); } }