Java tutorial
/* * DavMail POP/IMAP/SMTP/CalDav/LDAP Exchange Gateway * Copyright (C) 2009 Mickael Guessant * * 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; either version 2 * of the License, or (at your option) any later version. * * This program 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, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ package davmail.exchange; import davmail.BundleMessage; import davmail.Settings; import davmail.exception.DavMailAuthenticationException; import davmail.exception.DavMailException; import davmail.exception.WebdavNotAvailableException; import davmail.exchange.dav.DavExchangeSession; import davmail.exchange.ews.EwsExchangeSession; import davmail.http.DavGatewayHttpClientFacade; import org.apache.commons.httpclient.HttpClient; import org.apache.commons.httpclient.HttpStatus; import org.apache.commons.httpclient.methods.GetMethod; import java.io.IOException; import java.net.NetworkInterface; import java.net.SocketException; import java.net.UnknownHostException; import java.util.Enumeration; import java.util.HashMap; import java.util.Map; /** * Create ExchangeSession instances. */ public final class ExchangeSessionFactory { private static final Object LOCK = new Object(); private static final Map<PoolKey, ExchangeSession> POOL_MAP = new HashMap<PoolKey, ExchangeSession>(); private static boolean configChecked; private static boolean errorSent; static class PoolKey { final String url; final String userName; final String password; PoolKey(String url, String userName, String password) { this.url = url; this.userName = userName; this.password = password; } @Override public boolean equals(Object object) { return object == this || object instanceof PoolKey && ((PoolKey) object).url.equals(this.url) && ((PoolKey) object).userName.equals(this.userName) && ((PoolKey) object).password.equals(this.password); } @Override public int hashCode() { return url.hashCode() + userName.hashCode() + password.hashCode(); } } private ExchangeSessionFactory() { } /** * Create authenticated Exchange session * * @param userName user login * @param password user password * @return authenticated session * @throws IOException on error */ public static ExchangeSession getInstance(String userName, String password) throws IOException { String baseUrl = Settings.getProperty("davmail.url"); if (Settings.getBooleanProperty("davmail.server")) { return getInstance(baseUrl, userName, password); } else { // serialize session creation in workstation mode to avoid multiple OTP requests synchronized (LOCK) { return getInstance(baseUrl, userName, password); } } } private static String convertUserName(String userName) { String result = userName; // prepend default windows domain prefix String defaultDomain = Settings.getProperty("davmail.defaultDomain"); if (userName.indexOf('\\') < 0 && defaultDomain != null) { result = defaultDomain + '\\' + userName; } return result; } /** * Create authenticated Exchange session * * @param baseUrl OWA base URL * @param userName user login * @param password user password * @return authenticated session * @throws IOException on error */ public static ExchangeSession getInstance(String baseUrl, String userName, String password) throws IOException { ExchangeSession session = null; try { PoolKey poolKey = new PoolKey(baseUrl, convertUserName(userName), password); synchronized (LOCK) { session = POOL_MAP.get(poolKey); } if (session != null) { ExchangeSession.LOGGER.debug("Got session " + session + " from cache"); } if (session != null && session.isExpired()) { ExchangeSession.LOGGER.debug("Session " + session + " expired"); session = null; // expired session, remove from cache synchronized (LOCK) { POOL_MAP.remove(poolKey); } } if (session == null) { String enableEws = Settings.getProperty("davmail.enableEws", "auto"); if ("true".equals(enableEws)) { session = new EwsExchangeSession(poolKey.url, poolKey.userName, poolKey.password); } else { try { session = new DavExchangeSession(poolKey.url, poolKey.userName, poolKey.password); } catch (WebdavNotAvailableException e) { if ("auto".equals(enableEws)) { ExchangeSession.LOGGER.debug(e.getMessage() + ", retry with EWS"); session = new EwsExchangeSession(poolKey.url, poolKey.userName, poolKey.password); } else { throw e; } } } ExchangeSession.LOGGER.debug("Created new session: " + session); } // successful login, put session in cache synchronized (LOCK) { POOL_MAP.put(poolKey, session); } // session opened, future failure will mean network down configChecked = true; // Reset so next time an problem occurs message will be sent once errorSent = false; } catch (DavMailAuthenticationException exc) { throw exc; } catch (DavMailException exc) { throw exc; } catch (IllegalStateException exc) { throw exc; } catch (Exception exc) { handleNetworkDown(exc); } return session; } /** * Get a non expired session. * If the current session is not expired, return current session, else try to create a new session * * @param currentSession current session * @param userName user login * @param password user password * @return authenticated session * @throws IOException on error */ public static ExchangeSession getInstance(ExchangeSession currentSession, String userName, String password) throws IOException { ExchangeSession session = currentSession; try { if (session.isExpired()) { ExchangeSession.LOGGER.debug("Session " + session + " expired, trying to open a new one"); session = null; String baseUrl = Settings.getProperty("davmail.url"); PoolKey poolKey = new PoolKey(baseUrl, userName, password); // expired session, remove from cache synchronized (LOCK) { POOL_MAP.remove(poolKey); } session = getInstance(userName, password); } } catch (DavMailAuthenticationException exc) { ExchangeSession.LOGGER.debug("Unable to reopen session", exc); throw exc; } catch (Exception exc) { ExchangeSession.LOGGER.debug("Unable to reopen session", exc); handleNetworkDown(exc); } return session; } /** * Send a request to Exchange server to check current settings. * * @throws IOException if unable to access Exchange server */ public static void checkConfig() throws IOException { String url = Settings.getProperty("davmail.url"); HttpClient httpClient = DavGatewayHttpClientFacade.getInstance(url); GetMethod testMethod = new GetMethod(url); try { // get webMail root url (will not follow redirects) int status = DavGatewayHttpClientFacade.executeTestMethod(httpClient, testMethod); ExchangeSession.LOGGER.debug("Test configuration status: " + status); if (status != HttpStatus.SC_OK && status != HttpStatus.SC_UNAUTHORIZED && !DavGatewayHttpClientFacade.isRedirect(status)) { throw new DavMailException("EXCEPTION_CONNECTION_FAILED", url, status); } // session opened, future failure will mean network down configChecked = true; // Reset so next time an problem occurs message will be sent once errorSent = false; } catch (Exception exc) { handleNetworkDown(exc); } finally { testMethod.releaseConnection(); } } private static void handleNetworkDown(Exception exc) throws DavMailException { if (!checkNetwork() || configChecked) { ExchangeSession.LOGGER.warn(BundleMessage.formatLog("EXCEPTION_NETWORK_DOWN")); // log full stack trace for unknown errors if (!((exc instanceof UnknownHostException) || (exc instanceof NetworkDownException))) { ExchangeSession.LOGGER.debug(exc, exc); } throw new NetworkDownException("EXCEPTION_NETWORK_DOWN"); } else { BundleMessage message = new BundleMessage("EXCEPTION_CONNECT", exc.getClass().getName(), exc.getMessage()); if (errorSent) { ExchangeSession.LOGGER.warn(message); throw new NetworkDownException("EXCEPTION_DAVMAIL_CONFIGURATION", message); } else { // Mark that an error has been sent so you only get one // error in a row (not a repeating string of errors). errorSent = true; ExchangeSession.LOGGER.error(message); throw new DavMailException("EXCEPTION_DAVMAIL_CONFIGURATION", message); } } } /** * Get user password from session pool for SASL authentication * * @param userName Exchange user name * @return user password */ public static String getUserPassword(String userName) { String fullUserName = convertUserName(userName); for (PoolKey poolKey : POOL_MAP.keySet()) { if (poolKey.userName.equals(fullUserName)) { return poolKey.password; } } return null; } /** * Check if at least one network interface is up and active (i.e. has an address) * * @return true if network available */ static boolean checkNetwork() { boolean up = false; Enumeration<NetworkInterface> enumeration; try { enumeration = NetworkInterface.getNetworkInterfaces(); while (!up && enumeration.hasMoreElements()) { NetworkInterface networkInterface = enumeration.nextElement(); up = networkInterface.isUp() && !networkInterface.isLoopback() && networkInterface.getInetAddresses().hasMoreElements(); } } catch (NoSuchMethodError error) { ExchangeSession.LOGGER.debug("Unable to test network interfaces (not available under Java 1.5)"); up = true; } catch (SocketException exc) { ExchangeSession.LOGGER.error( "DavMail configuration exception: \n Error listing network interfaces " + exc.getMessage(), exc); } return up; } /** * Reset config check status and clear session pool. */ public static void reset() { configChecked = false; errorSent = false; POOL_MAP.clear(); } }