Java tutorial
/** * Copyright (c) 2011-2014, OpenIoT * * This file is part of OpenIoT. * * OpenIoT is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation, version 3 of the License. * * OpenIoT 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 Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with OpenIoT. If not, see <http://www.gnu.org/licenses/>. * * Contact: OpenIoT mailto: info@openiot.eu * @author Ali Salehi * @author Mehdi Riahi * @author Timotee Maret * @author Julien Eberle */ package org.openiot.gsn.http.rest; import org.openiot.gsn.beans.ContainerConfig; import org.openiot.gsn.beans.DataField; import org.openiot.gsn.beans.StreamElement; import org.openiot.gsn.wrappers.AbstractWrapper; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.security.KeyStore; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; import org.openiot.gsn.Main; import org.apache.http.*; import org.apache.http.auth.AuthScope; import org.apache.http.auth.AuthState; import org.apache.http.auth.Credentials; import org.apache.http.auth.UsernamePasswordCredentials; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.HttpPost; import org.apache.http.client.protocol.ClientContext; import org.apache.http.conn.scheme.PlainSocketFactory; import org.apache.http.conn.scheme.Scheme; import org.apache.http.conn.ssl.SSLSocketFactory; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.message.BasicNameValuePair; import org.apache.http.params.CoreProtocolPNames; import org.apache.http.protocol.BasicHttpContext; import org.apache.http.protocol.HTTP; import org.apache.http.protocol.HttpContext; import org.apache.log4j.Logger; import com.thoughtworks.xstream.XStream; import com.thoughtworks.xstream.XStreamException; public class PushRemoteWrapper extends AbstractWrapper { private static final int KEEP_ALIVE_PERIOD = 5000; private final transient Logger logger = Logger.getLogger(PushRemoteWrapper.class); private final XStream XSTREAM = StreamElement4Rest.getXstream(); private double uid = -1; //only set for push based delivery(default) private RemoteWrapperParamParser initParams; private DefaultHttpClient httpclient = new DefaultHttpClient(); private long lastReceivedTimestamp; protected DataField[] structure; List<NameValuePair> postParameters; public void dispose() { NotificationRegistry.getInstance().removeNotification(uid); } public boolean initialize() { try { initParams = new RemoteWrapperParamParser(getActiveAddressBean(), true); uid = Math.random(); postParameters = new ArrayList<NameValuePair>(); postParameters.add(new BasicNameValuePair(PushDelivery.NOTIFICATION_ID_KEY, Double.toString(uid))); postParameters.add( new BasicNameValuePair(PushDelivery.LOCAL_CONTACT_POINT, initParams.getLocalContactPoint())); // Init the http client if (initParams.isSSLRequired()) { KeyStore trustStore = KeyStore.getInstance(KeyStore.getDefaultType()); trustStore.load(new FileInputStream(new File("conf/servertestkeystore")), Main.getContainerConfig().getSSLKeyStorePassword().toCharArray()); SSLSocketFactory socketFactory = new SSLSocketFactory(trustStore); socketFactory.setHostnameVerifier(SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER); int sslPort = Main.getContainerConfig().getSSLPort() > 0 ? Main.getContainerConfig().getSSLPort() : ContainerConfig.DEFAULT_SSL_PORT; Scheme sch = new Scheme("https", socketFactory, sslPort); httpclient.getConnectionManager().getSchemeRegistry().register(sch); } Scheme plainsch = new Scheme("http", PlainSocketFactory.getSocketFactory(), Main.getContainerConfig().getContainerPort()); httpclient.getConnectionManager().getSchemeRegistry().register(plainsch); // lastReceivedTimestamp = initParams.getStartTime(); structure = registerAndGetStructure(); } catch (Exception e) { logger.error(e.getMessage(), e); NotificationRegistry.getInstance().removeNotification(uid); return false; } return true; } public DataField[] getOutputFormat() { return structure; } public String getWrapperName() { return "Push-Remote Wrapper"; } public DataField[] registerAndGetStructure() throws IOException, ClassNotFoundException { // Create the POST request HttpPost httpPost = new HttpPost(initParams.getRemoteContactPointEncoded(lastReceivedTimestamp)); // Add the POST parameters httpPost.setEntity(new UrlEncodedFormEntity(postParameters, HTTP.UTF_8)); // httpPost.getParams().setParameter(CoreProtocolPNames.USE_EXPECT_CONTINUE, Boolean.FALSE); // Create local execution context HttpContext localContext = new BasicHttpContext(); // NotificationRegistry.getInstance().addNotification(uid, this); int tries = 0; AuthState authState = null; // while (tries < 2) { tries++; HttpResponse response = null; try { // Execute the POST request response = httpclient.execute(httpPost, localContext); // int sc = response.getStatusLine().getStatusCode(); // if (sc == HttpStatus.SC_OK) { logger.debug(new StringBuilder().append("Wants to consume the structure packet from ") .append(initParams.getRemoteContactPoint())); structure = (DataField[]) XSTREAM.fromXML(response.getEntity().getContent()); logger.debug("Connection established for: " + initParams.getRemoteContactPoint()); break; } else { if (sc == HttpStatus.SC_UNAUTHORIZED) authState = (AuthState) localContext.getAttribute(ClientContext.TARGET_AUTH_STATE); // Target host authentication required else if (sc == HttpStatus.SC_PROXY_AUTHENTICATION_REQUIRED) authState = (AuthState) localContext.getAttribute(ClientContext.PROXY_AUTH_STATE); // Proxy authentication required else { logger.error(new StringBuilder().append("Unexpected POST status code returned: ").append(sc) .append("\nreason: ").append(response.getStatusLine().getReasonPhrase())); } if (authState != null) { if (initParams.getUsername() == null || (tries > 1 && initParams.getUsername() != null)) { logger.error("A valid username/password required to connect to the remote host: " + initParams.getRemoteContactPoint()); } else { AuthScope authScope = authState.getAuthScope(); logger.warn(new StringBuilder().append("Setting Credentials for host: ") .append(authScope.getHost()).append(":").append(authScope.getPort())); Credentials creds = new UsernamePasswordCredentials(initParams.getUsername(), initParams.getPassword()); httpclient.getCredentialsProvider().setCredentials(authScope, creds); } } } } catch (RuntimeException ex) { // In case of an unexpected exception you may want to abort // the HTTP request in order to shut down the underlying // connection and release it back to the connection manager. logger.warn("Aborting the HTTP POST request."); httpPost.abort(); throw ex; } finally { if (response != null && response.getEntity() != null) { response.getEntity().consumeContent(); } } } if (structure == null) throw new RuntimeException("Cannot connect to the remote host."); return structure; } public boolean manualDataInsertion(String Xstream4Rest) { logger.debug(new StringBuilder().append("Received Stream Element at the push wrapper.")); try { StreamElement4Rest se = (StreamElement4Rest) XSTREAM.fromXML(Xstream4Rest); StreamElement streamElement = se.toStreamElement(); // If the stream element is out of order, we accept the stream element and wait for the next (update the last received time and return true) if (isOutOfOrder(streamElement)) { lastReceivedTimestamp = streamElement.getTimeStamp(); return true; } // Otherwise, we first try to insert the stream element. // If the stream element was inserted succesfully, we wait for the next, // otherwise, we return false. boolean status = postStreamElement(streamElement); if (status) lastReceivedTimestamp = streamElement.getTimeStamp(); return status; } catch (SQLException e) { logger.warn(e.getMessage(), e); return false; } catch (XStreamException e) { logger.warn(e.getMessage(), e); return false; } } public void run() { HttpPost httpPost = new HttpPost(initParams.getRemoteContactPointEncoded(lastReceivedTimestamp)); // httpPost.getParams().setParameter(CoreProtocolPNames.USE_EXPECT_CONTINUE, Boolean.FALSE); // HttpResponse response = null; //This is acting as keep alive. // while (isActive()) { try { Thread.sleep(KEEP_ALIVE_PERIOD); httpPost.setEntity(new UrlEncodedFormEntity(postParameters, HTTP.UTF_8)); response = null; response = httpclient.execute(httpPost); int status = response.getStatusLine().getStatusCode(); if (status != RestStreamHanlder.SUCCESS_200) { logger.error("Cant register to the remote client, retrying in:" + (KEEP_ALIVE_PERIOD / 1000) + " seconds."); structure = registerAndGetStructure(); } } catch (Exception e) { logger.warn(e.getMessage(), e); } finally { if (response != null) { try { response.getEntity().getContent().close(); } catch (Exception e) { logger.warn(e.getMessage(), e); } } } } } }