Java tutorial
/* * Copyright (c) 2011 Lockheed Martin Corporation * * Licensed 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 org.eurekastreams.server.service.email; import java.util.ArrayList; import java.util.List; import javax.mail.FetchProfile; import javax.mail.Flags.Flag; import javax.mail.Folder; import javax.mail.Message; import javax.mail.MessagingException; import javax.mail.Store; import org.apache.commons.lang.StringUtils; import org.eurekastreams.commons.logging.LogFactory; import org.eurekastreams.server.service.actions.strategies.EmailerFactory; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Ingests email from a mailbox and processes it. */ public class ImapEmailIngester { /** Log. */ private final Logger log = LoggerFactory.getLogger(LogFactory.getClassName()); /** For getting a connection to the mail server. */ private final ImapStoreFactory storeFactory; /** Does the actual work on each message. */ private final MessageProcessor messageProcessor; /** Name of folder containing messages to process. */ private final String inputFolderName; /** Name of folder to receive messages that failed processing. */ private final String errorFolderName; /** Name of folder to receive messages that were successfully processed. */ private final String successFolderName; /** Name of folder to receive messages that are discarded (no-reply). */ private final String discardFolderName; /** For sending response emails. */ private final EmailerFactory emailerFactory; /** * Constructor. * * @param inStoreFactory * For getting a connection to the mail server. * @param inMessageProcessor * Does the actual work on each message. * @param inEmailerFactory * For sending response emails. * @param inInputFolderName * Name of folder containing messages to process. * @param inErrorFolderName * Name of folder to receive messages that failed processing. * @param inSuccessFolderName * Name of folder to receive messages that were successfully processed. * @param inDiscardFolderName * Name of folder to receive messages that are discarded (no-reply). */ public ImapEmailIngester(final ImapStoreFactory inStoreFactory, final MessageProcessor inMessageProcessor, final EmailerFactory inEmailerFactory, final String inInputFolderName, final String inErrorFolderName, final String inSuccessFolderName, final String inDiscardFolderName) { storeFactory = inStoreFactory; messageProcessor = inMessageProcessor; emailerFactory = inEmailerFactory; inputFolderName = inInputFolderName; errorFolderName = inErrorFolderName; successFolderName = inSuccessFolderName; discardFolderName = inDiscardFolderName; } /** * Ingests email from a mailbox. */ public void execute() { // get message store Store store; try { long startTime = System.nanoTime(); store = storeFactory.getStore(); log.debug("Connected to mail store in {}ns", System.nanoTime() - startTime); } catch (MessagingException ex) { log.error("Error getting message store.", ex); return; } try { // get folders Folder inputFolder = store.getFolder(inputFolderName); if (!inputFolder.exists()) { log.error("Input folder {} does not exist.", inputFolderName); return; } Folder successFolder = null; if (StringUtils.isNotBlank(successFolderName)) { successFolder = store.getFolder(successFolderName); if (!successFolder.exists()) { log.error("Success folder {} does not exist.", successFolderName); return; } } Folder discardFolder = null; if (StringUtils.isNotBlank(discardFolderName)) { discardFolder = store.getFolder(discardFolderName); if (!discardFolder.exists()) { log.error("Discard folder {} does not exist.", discardFolderName); return; } } Folder errorFolder = null; if (StringUtils.isNotBlank(errorFolderName)) { errorFolder = store.getFolder(errorFolderName); if (!errorFolder.exists()) { log.error("Error folder {} does not exist.", errorFolderName); return; } } inputFolder.open(Folder.READ_WRITE); // fetch messages // Note: Not preloading CONTENT_INFO. For some reason, preloading the content info (IMAP BODYSTRUCTURE) // causes the call to getContent to return empty. (As if there was a bug where getContent saw the cached // body structure and thought that the content itself was cached, but I'd think a bug like that would have // been found by many people and fixed long ago, so I'm assuming it's something else.) FetchProfile fp = new FetchProfile(); fp.add(FetchProfile.Item.ENVELOPE); Message[] msgs = inputFolder.getMessages(); inputFolder.fetch(msgs, fp); log.debug("About to process {} messages", msgs.length); // process each message if (msgs.length > 0) { List<Message> successMessages = new ArrayList<Message>(); List<Message> errorMessages = new ArrayList<Message>(); List<Message> discardMessages = new ArrayList<Message>(); List<Message> responseMessages = new ArrayList<Message>(); for (int i = 0; i < msgs.length; i++) { Message message = msgs[i]; try { boolean processed = messageProcessor.execute(message, responseMessages); (processed ? successMessages : discardMessages).add(message); } catch (Exception ex) { log.error("Failed to process email message.", ex); errorMessages.add(message); } } // send response messages for (Message responseMessage : responseMessages) { emailerFactory.sendMail(responseMessage); } // move and purge messages if (successFolder != null && !successMessages.isEmpty()) { inputFolder.copyMessages(successMessages.toArray(new Message[successMessages.size()]), successFolder); } if (discardFolder != null && !discardMessages.isEmpty()) { inputFolder.copyMessages(discardMessages.toArray(new Message[discardMessages.size()]), discardFolder); } if (errorFolder != null && !errorMessages.isEmpty()) { inputFolder.copyMessages(errorMessages.toArray(new Message[errorMessages.size()]), errorFolder); } for (int i = 0; i < msgs.length; i++) { msgs[i].setFlag(Flag.DELETED, true); } log.info("{} messages processed: {} successful, {} discarded, {} failed.", new Object[] { msgs.length, successMessages.size(), discardMessages.size(), errorMessages.size() }); } // close folder inputFolder.close(true); } catch (MessagingException ex) { log.error("Error ingesting email.", ex); } catch (Exception ex) { log.error("Error ingesting email.", ex); } finally { // close store try { store.close(); } catch (MessagingException ex) { log.error("Error closing message store.", ex); } } } }