Java tutorial
/******************************************************************************* *Copyright (c) 2009 Eucalyptus Systems, Inc. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, only version 3 of the License. * * * This file 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 General Public License * for more details. * * You should have received a copy of the GNU General Public License along * with this program. If not, see <http://www.gnu.org/licenses/>. * * Please contact Eucalyptus Systems, Inc., 130 Castilian * Dr., Goleta, CA 93101 USA or visit <http://www.eucalyptus.com/licenses/> * if you need additional information or have any questions. * * This file may incorporate work covered under the following copyright and * permission notice: * * Software License Agreement (BSD License) * * Copyright (c) 2008, Regents of the University of California * All rights reserved. * * Redistribution and use of this software in source and binary forms, with * or without modification, are permitted provided that the following * conditions are met: * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. USERS OF * THIS SOFTWARE ACKNOWLEDGE THE POSSIBLE PRESENCE OF OTHER OPEN SOURCE * LICENSED MATERIAL, COPYRIGHTED MATERIAL OR PATENTED MATERIAL IN THIS * SOFTWARE, AND IF ANY SUCH MATERIAL IS DISCOVERED THE PARTY DISCOVERING * IT MAY INFORM DR. RICH WOLSKI AT THE UNIVERSITY OF CALIFORNIA, SANTA * BARBARA WHO WILL THEN ASCERTAIN THE MOST APPROPRIATE REMEDY, WHICH IN * THE REGENTS DISCRETION MAY INCLUDE, WITHOUT LIMITATION, REPLACEMENT * OF THE CODE SO IDENTIFIED, LICENSING OF THE CODE SO IDENTIFIED, OR * WITHDRAWAL OF THE CODE CAPABILITY TO THE EXTENT NEEDED TO COMPLY WITH * ANY SUCH LICENSES OR RIGHTS. *******************************************************************************/ package edu.ucsb.eucalyptus.admin.server.extensions.store; import java.util.Map; import java.util.List; import java.io.IOException; import java.io.InputStream; import java.net.URL; import java.net.MalformedURLException; import com.google.gwt.user.server.rpc.RemoteServiceServlet; import org.apache.commons.httpclient.HttpClient; import org.apache.commons.httpclient.HttpMethod; import org.apache.commons.httpclient.NameValuePair; import org.apache.commons.httpclient.methods.GetMethod; import org.apache.commons.httpclient.methods.PostMethod; import org.apache.commons.httpclient.HttpException; import edu.ucsb.eucalyptus.admin.server.EucalyptusWebBackendImpl; import edu.ucsb.eucalyptus.admin.client.UserInfoWeb; import edu.ucsb.eucalyptus.admin.client.extensions.store.ImageStoreService; public class ImageStoreServiceImpl extends RemoteServiceServlet implements ImageStoreService { /* These are fixed: */ private final static String API_VERSION = "2009-10-01"; private final static String SIGNATURE_VERSION = "2"; private final static String SIGNATURE_METHOD = "HmacSHA256"; private final static int EXPIRES_DELAY_SECONDS = 30; public String requestJSON(String sessionId, Method method, String uri, Parameter[] params) { UserInfoWeb user; try { user = EucalyptusWebBackendImpl.getUserRecord(sessionId); } catch (Exception e) { return errorJSON("Session authentication error: " + e.getMessage()); } NameValuePair[] finalParams; try { finalParams = getFinalParameters(method, uri, params, user); } catch (MalformedURLException e) { return errorJSON("Malformed URL: " + uri); } HttpClient client = new HttpClient(); HttpMethod httpMethod; if (method == Method.GET) { GetMethod getMethod = new GetMethod(uri); httpMethod = getMethod; getMethod.setQueryString(finalParams); } else if (method == Method.POST) { PostMethod postMethod = new PostMethod(uri); httpMethod = postMethod; postMethod.addParameters(finalParams); } else { throw new UnsupportedOperationException("Unknown method"); } try { int statusCode = client.executeMethod(httpMethod); String str = ""; InputStream in = httpMethod.getResponseBodyAsStream(); byte[] readBytes = new byte[1024]; int bytesRead = -1; while ((bytesRead = in.read(readBytes)) > 0) { str += new String(readBytes, 0, bytesRead); } return str; } catch (HttpException e) { return errorJSON("Protocol error: " + e.getMessage()); } catch (IOException e) { return errorJSON("Proxy error: " + e.getMessage()); } finally { httpMethod.releaseConnection(); } } private String errorJSON(String errorMessage) { return "{\"error-message\": \"" + escapeString(errorMessage) + "\"}"; } private String escapeString(String value) { return value.replace("\\", "\\\\").replace("\"", "\\\"").replace("\b", "\\b").replace("\f", "\\f") .replace("\n", "\\n").replace("\r", "\\r").replace("\t", "\\t"); } private NameValuePair[] getFinalParameters(Method method, String uri, Parameter[] params, UserInfoWeb user) throws MalformedURLException { if (params == null) { // Simplify the logic below. params = new Parameter[0]; } URL url = new URL(uri); SignatureGenerator signatureGenerator = new SignatureGenerator(method.toString(), url.getHost(), url.getPort(), url.getPath()); Parameter[] finalParams = new Parameter[params.length + 7]; System.arraycopy(params, 0, finalParams, 0, params.length); int i = params.length; finalParams[i++] = new Parameter("SignatureMethod", SIGNATURE_METHOD); finalParams[i++] = new Parameter("SignatureVersion", SIGNATURE_VERSION); finalParams[i++] = new Parameter("Version", API_VERSION); finalParams[i++] = new Parameter("ClientId", user.getQueryId()); finalParams[i++] = new Parameter("Expires", new Long((System.currentTimeMillis() / 1000) + EXPIRES_DELAY_SECONDS).toString()); finalParams[i++] = new Parameter("Nonce", new Long(System.nanoTime()).toString()); for (Parameter param : finalParams) { if (param != null) { signatureGenerator.addParameter(param.getName(), param.getValue()); } } String signature = signatureGenerator.getSignature(user.getSecretKey()); finalParams[i++] = new Parameter("Signature", signature); return getNameValuePairs(finalParams); } private NameValuePair[] getNameValuePairs(Parameter[] params) { NameValuePair[] pairs = new NameValuePair[params.length]; for (int i = 0; i != params.length; i++) { pairs[i] = new NameValuePair(params[i].getName(), params[i].getValue()); } return pairs; } }