Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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 net.elasticgrid.rackspace.common; import net.elasticgrid.rackspace.cloudservers.internal.CloudServersAPIFault; import org.apache.commons.io.IOUtils; import org.apache.http.Header; import org.apache.http.HeaderElement; import org.apache.http.HttpEntity; import org.apache.http.HttpException; import org.apache.http.HttpHost; import org.apache.http.HttpRequest; import org.apache.http.HttpRequestInterceptor; import org.apache.http.HttpResponse; import org.apache.http.HttpResponseInterceptor; import org.apache.http.HttpVersion; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpRequestBase; import org.apache.http.client.methods.HttpPost; import org.apache.http.client.methods.HttpEntityEnclosingRequestBase; import org.apache.http.conn.ClientConnectionManager; import org.apache.http.conn.params.ConnManagerParams; import org.apache.http.conn.params.ConnRoutePNames; import org.apache.http.conn.params.ConnPerRouteBean; import org.apache.http.conn.scheme.PlainSocketFactory; import org.apache.http.conn.scheme.Scheme; import org.apache.http.conn.scheme.SchemeRegistry; import org.apache.http.conn.ssl.SSLSocketFactory; import org.apache.http.entity.HttpEntityWrapper; import org.apache.http.entity.EntityTemplate; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager; import org.apache.http.params.BasicHttpParams; import org.apache.http.params.HttpParams; import org.apache.http.params.HttpProtocolParams; import org.apache.http.protocol.HttpContext; import org.jibx.runtime.BindingDirectory; import org.jibx.runtime.IBindingFactory; import org.jibx.runtime.IUnmarshallingContext; import org.jibx.runtime.JiBXException; import java.io.IOException; import java.io.InputStream; import java.io.ByteArrayOutputStream; import java.util.Properties; import java.util.logging.Level; import java.util.logging.Logger; import java.util.zip.GZIPInputStream; /** * This class provides common code to the REST connection classes. * Logging: * <table> * <thead> * <th>Level</th> * <th align="left">Information</th> * </thead> * <tbody> * <tr> * <td>WARNING</td> * <td>Retries, Expired Authentication before the request is automatically retried</td> * </tr> * <tr> * <td>INFO</td> * <td>Request URI & Method</td> * </tr> * <tr> * <td>FINEST</td> * <td>Request Body, Response Body</td> * </tr> * </tbody> * </table> * * @author Jerome Bernard */ public class RackspaceConnection { // this is the number of automatic retries private int maxRetries = 5; private String userAgent = "Elastic-Grid/"; private HttpClient hc = null; private int maxConnections = 100; private String proxyHost = null; private int proxyPort; private int connectionManagerTimeout = 0; private int soTimeout = 0; private int connectionTimeout = 0; private final String username; private final String apiKey; private String serverManagementURL; private String storageURL; private String cdnManagementURL; private String authToken; private boolean authenticated = false; private static final String API_AUTH_URL = "https://auth.api.rackspacecloud.com/v1.0"; private static final Logger logger = Logger.getLogger(RackspaceConnection.class.getName()); /** * Initializes the Rackspace connection with the Rackspace login information. * * @param username the Rackspace username * @param apiKey the Rackspace API key * @throws RackspaceException if the credentials are invalid * @throws IOException if there is a network issue * @see #authenticate() */ public RackspaceConnection(String username, String apiKey) throws RackspaceException, IOException { this.username = username; this.apiKey = apiKey; String version; try { Properties props = new Properties(); props.load(this.getClass().getClassLoader().getResourceAsStream("version.properties")); version = props.getProperty("version"); } catch (Exception ex) { version = "?"; } userAgent = userAgent + version + " (" + System.getProperty("os.arch") + "; " + System.getProperty("os.name") + ")"; authenticate(); } /** * Authenticate on Rackspace API. Tokens are only valid for 24 hours, so client code should expect token to expire * and renew them if needed. * * @return the auth token, valid for 24 hours * @throws RackspaceException if the credentials are invalid * @throws IOException if there is a network issue */ public String authenticate() throws RackspaceException, IOException { logger.info("Authenticating to Rackspace API..."); HttpGet request = new HttpGet(API_AUTH_URL); request.addHeader("X-Auth-User", username); request.addHeader("X-Auth-Key", apiKey); HttpResponse response = getHttpClient().execute(request); int statusCode = response.getStatusLine().getStatusCode(); switch (statusCode) { case 204: if (response.getFirstHeader("X-Server-Management-Url") != null) serverManagementURL = response.getFirstHeader("X-Server-Management-Url").getValue(); if (response.getFirstHeader("X-Storage-Url") != null) storageURL = response.getFirstHeader("X-Storage-Url").getValue(); if (response.getFirstHeader("X-CDN-Management-Url") != null) cdnManagementURL = response.getFirstHeader("X-CDN-Management-Url").getValue(); authToken = response.getFirstHeader("X-Auth-Token").getValue(); authenticated = true; return authToken; case 401: throw new RackspaceException("Invalid credentials: " + response.getStatusLine().getReasonPhrase()); default: throw new RackspaceException("Unexpected HTTP response"); } } /** * Make a http request and process the response. This method also performs automatic retries. * * @param request the HTTP method to use (GET, POST, DELETE, etc) * @param respType the class that represents the desired/expected return type * @return the unmarshalled entity * @throws RackspaceException * @throws IOException if there is an I/O exception * @throws HttpException if there is an HTTP exception * @throws JiBXException if the result can't be unmarshalled */ @SuppressWarnings("unchecked") protected <T> T makeRequest(HttpRequestBase request, Class<T> respType) throws HttpException, IOException, JiBXException, RackspaceException { if (!authenticated) authenticate(); // add auth params, and protocol specific headers request.addHeader("X-Auth-Token", getAuthToken()); // set accept and content-type headers request.setHeader("Accept", "application/xml; charset=UTF-8"); request.setHeader("Accept-Encoding", "gzip"); request.setHeader("Content-Type", "application/xml; charset=UTF-8"); // send the request T result = null; boolean done = false; int retries = 0; boolean doRetry = false; RackspaceException error = null; do { HttpResponse response = null; if (retries > 0) logger.log(Level.INFO, "Retry #{0}: querying via {1} {2}", new Object[] { retries, request.getMethod(), request.getURI() }); else logger.log(Level.INFO, "Querying via {0} {1}", new Object[] { request.getMethod(), request.getURI() }); if (logger.isLoggable(Level.FINEST) && request instanceof HttpEntityEnclosingRequestBase) { HttpEntity entity = ((HttpEntityEnclosingRequestBase) request).getEntity(); if (entity instanceof EntityTemplate) { EntityTemplate template = (EntityTemplate) entity; ByteArrayOutputStream baos = null; try { baos = new ByteArrayOutputStream(); template.writeTo(baos); logger.log(Level.FINEST, "Request body:\n{0}", baos.toString()); } finally { IOUtils.closeQuietly(baos); } } } InputStream entityStream = null; HttpEntity entity = null; if (logger.isLoggable(Level.FINEST)) { response = getHttpClient().execute(request); entity = response.getEntity(); try { entityStream = entity.getContent(); logger.log(Level.FINEST, "Response body on " + request.getURI() + " via " + request.getMethod() + ":\n" + IOUtils.toString(entityStream)); } finally { IOUtils.closeQuietly(entityStream); } } response = getHttpClient().execute(request); int statusCode = response.getStatusLine().getStatusCode(); entity = response.getEntity(); switch (statusCode) { case 200: case 202: case 203: try { entityStream = entity.getContent(); IBindingFactory bindingFactory = BindingDirectory.getFactory(respType); IUnmarshallingContext unmarshallingCxt = bindingFactory.createUnmarshallingContext(); result = (T) unmarshallingCxt.unmarshalDocument(entityStream, "UTF-8"); } finally { entity.consumeContent(); IOUtils.closeQuietly(entityStream); } done = true; break; case 503: // service unavailable logger.log(Level.WARNING, "Service unavailable on {0} via {1}. Will retry in {2} seconds.", new Object[] { request.getURI(), request.getMethod(), Math.pow(2.0, retries + 1) }); doRetry = true; break; case 401: // unauthorized logger.warning("Not authenticated or authentication token expired. Authenticating..."); authenticate(); doRetry = true; break; case 417: throw new RackspaceException(new IllegalArgumentException("Some parameters are invalid!")); // TODO: temp hack 'til Rackspace API is fixed! case 400: case 500: default: try { entityStream = entity.getContent(); IBindingFactory bindingFactory = BindingDirectory.getFactory(CloudServersAPIFault.class); IUnmarshallingContext unmarshallingCxt = bindingFactory.createUnmarshallingContext(); CloudServersAPIFault fault = (CloudServersAPIFault) unmarshallingCxt .unmarshalDocument(entityStream, "UTF-8"); done = true; throw new RackspaceException(fault.getCode(), fault.getMessage(), fault.getDetails()); } catch (JiBXException e) { response = getHttpClient().execute(request); entity = response.getEntity(); entityStream = entity.getContent(); logger.log(Level.SEVERE, "Can't unmarshal response from " + request.getURI() + " via " + request.getMethod() + ":" + IOUtils.toString(entityStream)); e.printStackTrace(); throw e; } finally { entity.consumeContent(); IOUtils.closeQuietly(entityStream); } } if (doRetry) { retries++; if (retries > maxRetries) { throw new HttpException("Number of retries exceeded for " + request.getURI(), error); } doRetry = false; try { Thread.sleep((int) Math.pow(2.0, retries) * 1000); } catch (InterruptedException ex) { // do nothing } } } while (!done); return result; } private void configureHttpClient() { HttpParams params = new BasicHttpParams(); HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1); HttpProtocolParams.setContentCharset(params, "UTF-8"); HttpProtocolParams.setUserAgent(params, userAgent); HttpProtocolParams.setUseExpectContinue(params, true); // params.setBooleanParameter("http.tcp.nodelay", true); // params.setBooleanParameter("http.coonection.stalecheck", false); ConnManagerParams.setTimeout(params, getConnectionManagerTimeout()); ConnManagerParams.setMaxTotalConnections(params, getMaxConnections()); ConnManagerParams.setMaxConnectionsPerRoute(params, new ConnPerRouteBean(getMaxConnections())); params.setIntParameter("http.socket.timeout", getSoTimeout()); params.setIntParameter("http.connection.timeout", getConnectionTimeout()); SchemeRegistry schemeRegistry = new SchemeRegistry(); schemeRegistry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80)); schemeRegistry.register(new Scheme("https", SSLSocketFactory.getSocketFactory(), 443)); ClientConnectionManager connMgr = new ThreadSafeClientConnManager(params, schemeRegistry); hc = new DefaultHttpClient(connMgr, params); ((DefaultHttpClient) hc).addRequestInterceptor(new HttpRequestInterceptor() { public void process(HttpRequest request, HttpContext context) throws HttpException, IOException { if (!request.containsHeader("Accept-Encoding")) { request.addHeader("Accept-Encoding", "gzip"); } } }); ((DefaultHttpClient) hc).addResponseInterceptor(new HttpResponseInterceptor() { public void process(HttpResponse response, HttpContext context) throws HttpException, IOException { HttpEntity entity = response.getEntity(); if (entity == null) return; Header ceHeader = entity.getContentEncoding(); if (ceHeader != null) { for (HeaderElement codec : ceHeader.getElements()) { if (codec.getName().equalsIgnoreCase("gzip")) { response.setEntity(new GzipDecompressingEntity(response.getEntity())); return; } } } } }); if (proxyHost != null) { HttpHost proxy = new HttpHost(proxyHost, proxyPort); hc.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy); logger.info("Proxy Host set to " + proxyHost + ":" + proxyPort); } } public String getAuthToken() { return authToken; } public String getServerManagementURL() { return serverManagementURL; } public String getStorageURL() { return storageURL; } public String getCdnManagementURL() { return cdnManagementURL; } protected HttpClient getHttpClient() { if (hc == null) { configureHttpClient(); } return hc; } public void setHttpClient(HttpClient hc) { this.hc = hc; } public int getConnectionManagerTimeout() { return connectionManagerTimeout; } public void setConnectionManagerTimeout(int timeout) { connectionManagerTimeout = timeout; hc = null; } public int getSoTimeout() { return soTimeout; } public void setSoTimeout(int timeout) { soTimeout = timeout; hc = null; } public int getConnectionTimeout() { return connectionTimeout; } public void setConnectionTimeout(int timeout) { connectionTimeout = timeout; hc = null; } public int getMaxConnections() { return maxConnections; } public void setMaxConnections(int maxConnections) { this.maxConnections = maxConnections; hc = null; } public String getProxyHost() { return proxyHost; } public void setProxyHost(String proxyHost) { this.proxyHost = proxyHost; hc = null; } public int getProxyPort() { return proxyPort; } public void setProxyPort(int proxyPort) { this.proxyPort = proxyPort; hc = null; } static class GzipDecompressingEntity extends HttpEntityWrapper { public GzipDecompressingEntity(final HttpEntity entity) { super(entity); } @Override public InputStream getContent() throws IOException, IllegalStateException { // the wrapped entity's getContent() decides about repeatability InputStream wrappedin = wrappedEntity.getContent(); return new GZIPInputStream(wrappedin); } @Override public long getContentLength() { // length of ungzipped content is not known return -1; } } }