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 examples.mail; import java.io.BufferedWriter; import java.io.File; import java.io.FileWriter; import java.io.IOException; import java.net.URI; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.Iterator; import java.util.List; import java.util.TimeZone; import java.util.regex.Matcher; import java.util.regex.Pattern; import org.apache.commons.net.PrintCommandListener; import org.apache.commons.net.ProtocolCommandEvent; import org.apache.commons.net.imap.IMAP.IMAPChunkListener; import org.apache.commons.net.imap.IMAP; import org.apache.commons.net.imap.IMAPClient; import org.apache.commons.net.imap.IMAPReply; /** * This is an example program demonstrating how to use the IMAP[S]Client class. * This program connects to a IMAP[S] server and exports selected messages from a folder into an mbox file. * <p> * Usage: IMAPExportMbox imap[s]://user:password@host[:port]/folder/path <mboxfile> [sequence-set] [item-names] * <p> * An example sequence-set might be: * <ul> * <li>11,2,3:10,20:*</li> * <li>1:* - this is the default</li> * </ul> * <p> * Some example item-names might be: * <ul> * <li>BODY.PEEK[HEADER]</li> * <li>'BODY.PEEK[HEADER.FIELDS (SUBJECT)]'</li> * <li>ALL</li> * <li>ENVELOPE</li> * <li>'(INTERNALDATE BODY.PEEK[])' - this is the default</li> * </ul> * <p> * For example:<br> * IMAPExportMbox imaps://username:password@imap.googlemail.com/messages_for_export exported.mbox 1:10,20<br> * IMAPExportMbox imaps://username:password@imap.googlemail.com/messages_for_export exported.mbox 3 ENVELOPE<br> * <p> * Note that the sequence-set is passed unmodified to the FETCH command. * The item names are wrapped in parentheses if more than one is provided. * Otherwise, the parameter is assumed to be wrapped if necessary. * Parameters with spaces must be quoted otherwise the OS shell will normally treat them as separate parameters. * Also the listener that writes the mailbox only captures the multi-line responses. * It does not capture the output from ENVELOPE commands. */ public final class IMAPExportMbox { private static final String CRLF = "\r\n"; private static final String LF = "\n"; private static final String EOL_DEFAULT = System.getProperty("line.separator"); private static final Pattern PATFROM = Pattern.compile(">*From "); // unescaped From_ // e.g. * nnn (INTERNALDATE "27-Oct-2013 07:43:24 +0000" BODY[] {nn} ...) private static final Pattern PATID = // INTERNALDATE Pattern.compile(".*INTERNALDATE \"(\\d\\d-\\w{3}-\\d{4} \\d\\d:\\d\\d:\\d\\d [+-]\\d+)\""); private static final int PATID_DATE_GROUP = 1; private static final Pattern PATSEQ = Pattern.compile("\\* (\\d+) "); // Sequence number private static final int PATSEQ_SEQUENCE_GROUP = 1; // e.g. * 382 EXISTS private static final Pattern PATEXISTS = Pattern.compile("\\* (\\d+) EXISTS"); // Response from SELECT // AAAC NO [TEMPFAIL] FETCH Temporary failure on server [CODE: WBL] private static final Pattern PATTEMPFAIL = Pattern.compile("[A-Z]{4} NO \\[TEMPFAIL\\] FETCH .*"); private static final int CONNECT_TIMEOUT = 10; // Seconds private static final int READ_TIMEOUT = 10; public static void main(String[] args) throws IOException { int connect_timeout = CONNECT_TIMEOUT; int read_timeout = READ_TIMEOUT; int argIdx = 0; String eol = EOL_DEFAULT; boolean printHash = false; boolean printMarker = false; int retryWaitSecs = 0; for (argIdx = 0; argIdx < args.length; argIdx++) { if (args[argIdx].equals("-c")) { connect_timeout = Integer.parseInt(args[++argIdx]); } else if (args[argIdx].equals("-r")) { read_timeout = Integer.parseInt(args[++argIdx]); } else if (args[argIdx].equals("-R")) { retryWaitSecs = Integer.parseInt(args[++argIdx]); } else if (args[argIdx].equals("-LF")) { eol = LF; } else if (args[argIdx].equals("-CRLF")) { eol = CRLF; } else if (args[argIdx].equals("-.")) { printHash = true; } else if (args[argIdx].equals("-X")) { printMarker = true; } else { break; } } final int argCount = args.length - argIdx; if (argCount < 2) { System.err.println("Usage: IMAPExportMbox [-LF|-CRLF] [-c n] [-r n] [-R n] [-.] [-X]" + " imap[s]://user:password@host[:port]/folder/path [+|-]<mboxfile> [sequence-set] [itemnames]"); System.err.println( "\t-LF | -CRLF set end-of-line to LF or CRLF (default is the line.separator system property)"); System.err.println("\t-c connect timeout in seconds (default 10)"); System.err.println("\t-r read timeout in seconds (default 10)"); System.err.println("\t-R temporary failure retry wait in seconds (default 0; i.e. disabled)"); System.err.println("\t-. print a . for each complete message received"); System.err.println("\t-X print the X-IMAP line for each complete message received"); System.err.println( "\tthe mboxfile is where the messages are stored; use '-' to write to standard output."); System.err.println( "\tPrefix filename with '+' to append to the file. Prefix with '-' to allow overwrite."); System.err.println( "\ta sequence-set is a list of numbers/number ranges e.g. 1,2,3-10,20:* - default 1:*"); System.err .println("\titemnames are the message data item name(s) e.g. BODY.PEEK[HEADER.FIELDS (SUBJECT)]" + " or a macro e.g. ALL - default (INTERNALDATE BODY.PEEK[])"); System.exit(1); } final URI uri = URI.create(args[argIdx++]); final String file = args[argIdx++]; String sequenceSet = argCount > 2 ? args[argIdx++] : "1:*"; final String itemNames; // Handle 0, 1 or multiple item names if (argCount > 3) { if (argCount > 4) { StringBuilder sb = new StringBuilder(); sb.append("("); for (int i = 4; i <= argCount; i++) { if (i > 4) { sb.append(" "); } sb.append(args[argIdx++]); } sb.append(")"); itemNames = sb.toString(); } else { itemNames = args[argIdx++]; } } else { itemNames = "(INTERNALDATE BODY.PEEK[])"; } final boolean checkSequence = sequenceSet.matches("\\d+:(\\d+|\\*)"); // are we expecting a sequence? final MboxListener chunkListener; if (file.equals("-")) { chunkListener = null; } else if (file.startsWith("+")) { final File mbox = new File(file.substring(1)); System.out.println("Appending to file " + mbox); chunkListener = new MboxListener(new BufferedWriter(new FileWriter(mbox, true)), eol, printHash, printMarker, checkSequence); } else if (file.startsWith("-")) { final File mbox = new File(file.substring(1)); System.out.println("Writing to file " + mbox); chunkListener = new MboxListener(new BufferedWriter(new FileWriter(mbox, false)), eol, printHash, printMarker, checkSequence); } else { final File mbox = new File(file); if (mbox.exists()) { throw new IOException("mailbox file: " + mbox + " already exists!"); } System.out.println("Creating file " + mbox); chunkListener = new MboxListener(new BufferedWriter(new FileWriter(mbox)), eol, printHash, printMarker, checkSequence); } String path = uri.getPath(); if (path == null || path.length() < 1) { throw new IllegalArgumentException("Invalid folderPath: '" + path + "'"); } String folder = path.substring(1); // skip the leading / // suppress login details final PrintCommandListener listener = new PrintCommandListener(System.out, true) { @Override public void protocolReplyReceived(ProtocolCommandEvent event) { if (event.getReplyCode() != IMAPReply.PARTIAL) { // This is dealt with by the chunk listener super.protocolReplyReceived(event); } } }; // Connect and login final IMAPClient imap = IMAPUtils.imapLogin(uri, connect_timeout * 1000, listener); String maxIndexInFolder = null; try { imap.setSoTimeout(read_timeout * 1000); if (!imap.select(folder)) { throw new IOException("Could not select folder: " + folder); } for (String line : imap.getReplyStrings()) { maxIndexInFolder = matches(line, PATEXISTS, 1); if (maxIndexInFolder != null) { break; } } if (chunkListener != null) { imap.setChunkListener(chunkListener); } // else the command listener displays the full output without processing while (true) { boolean ok = imap.fetch(sequenceSet, itemNames); // If the fetch failed, can we retry? if (!ok && retryWaitSecs > 0 && chunkListener != null && checkSequence) { final String replyString = imap.getReplyString(); //includes EOL if (startsWith(replyString, PATTEMPFAIL)) { System.err.println("Temporary error detected, will retry in " + retryWaitSecs + "seconds"); sequenceSet = (chunkListener.lastSeq + 1) + ":*"; try { Thread.sleep(retryWaitSecs * 1000); } catch (InterruptedException e) { // ignored } } else { throw new IOException( "FETCH " + sequenceSet + " " + itemNames + " failed with " + replyString); } } else { break; } } } catch (IOException ioe) { String count = chunkListener == null ? "?" : Integer.toString(chunkListener.total); System.err.println("FETCH " + sequenceSet + " " + itemNames + " failed after processing " + count + " complete messages "); if (chunkListener != null) { System.err.println("Last complete response seen: " + chunkListener.lastFetched); } throw ioe; } finally { if (printHash) { System.err.println(); } if (chunkListener != null) { chunkListener.close(); final Iterator<String> missingIds = chunkListener.missingIds.iterator(); if (missingIds.hasNext()) { StringBuilder sb = new StringBuilder(); for (;;) { sb.append(missingIds.next()); if (!missingIds.hasNext()) { break; } sb.append(","); } System.err.println("*** Missing ids: " + sb.toString()); } } imap.logout(); imap.disconnect(); } if (chunkListener != null) { System.out.println("Processed " + chunkListener.total + " messages."); } if (maxIndexInFolder != null) { System.out.println("Folder contained " + maxIndexInFolder + " messages."); } } private static boolean startsWith(String input, Pattern pat) { Matcher m = pat.matcher(input); return m.lookingAt(); } private static String matches(String input, Pattern pat, int index) { Matcher m = pat.matcher(input); if (m.lookingAt()) { return m.group(index); } return null; } private static class MboxListener implements IMAPChunkListener { private final BufferedWriter bw; volatile int total = 0; volatile String lastFetched; volatile List<String> missingIds = new ArrayList<String>(); volatile long lastSeq = -1; private final String eol; private final SimpleDateFormat DATE_FORMAT // for mbox From_ lines = new SimpleDateFormat("EEE MMM dd HH:mm:ss YYYY"); // e.g. INTERNALDATE "27-Oct-2013 07:43:24 +0000" private final SimpleDateFormat IDPARSE // for parsing INTERNALDATE = new SimpleDateFormat("dd-MMM-yyyy HH:mm:ss Z"); private final boolean printHash; private final boolean printMarker; private final boolean checkSequence; MboxListener(BufferedWriter bw, String eol, boolean printHash, boolean printMarker, boolean checkSequence) throws IOException { this.eol = eol; this.printHash = printHash; this.printMarker = printMarker; DATE_FORMAT.setTimeZone(TimeZone.getTimeZone("GMT")); this.bw = bw; this.checkSequence = checkSequence; } @Override public boolean chunkReceived(IMAP imap) { final String[] replyStrings = imap.getReplyStrings(); Date received = new Date(); final String firstLine = replyStrings[0]; Matcher m = PATID.matcher(firstLine); if (m.lookingAt()) { // found a match String date = m.group(PATID_DATE_GROUP); try { received = IDPARSE.parse(date); } catch (ParseException e) { System.err.println(e); } } else { System.err.println("No timestamp found in: " + firstLine + " - using current time"); } String replyTo = "MAILER-DAEMON"; // default for (int i = 1; i < replyStrings.length - 1; i++) { final String line = replyStrings[i]; if (line.startsWith("Return-Path: ")) { String[] parts = line.split(" ", 2); replyTo = parts[1]; if (replyTo.startsWith("<")) { replyTo = replyTo.substring(1, replyTo.length() - 1); // drop <> wrapper } else { System.err.println("Unexpected Return-path:" + line + " in " + firstLine); } break; } } try { // Add initial mbox header line bw.append("From "); bw.append(replyTo); bw.append(' '); bw.append(DATE_FORMAT.format(received)); bw.append(eol); // Debug bw.append("X-IMAP-Response: ").append(firstLine).append(eol); if (printMarker) { System.err.println("[" + total + "] " + firstLine); } // Skip first and last lines for (int i = 1; i < replyStrings.length - 1; i++) { final String line = replyStrings[i]; if (startsWith(line, PATFROM)) { bw.append('>'); // Escape a From_ line } bw.append(line); bw.append(eol); } // The last line ends with the trailing closing ")" which needs to be stripped String lastLine = replyStrings[replyStrings.length - 1]; final int lastLength = lastLine.length(); if (lastLength > 1) { // there's some content, we need to save it bw.append(lastLine, 0, lastLength - 1); bw.append(eol); } bw.append(eol); // blank line between entries } catch (IOException e) { e.printStackTrace(); throw new RuntimeException(e); // chunkReceived cannot throw a checked Exception } lastFetched = firstLine; total++; if (checkSequence) { m = PATSEQ.matcher(firstLine); if (m.lookingAt()) { // found a match final long msgSeq = Long.parseLong(m.group(PATSEQ_SEQUENCE_GROUP)); // Cannot fail to parse if (lastSeq != -1) { long missing = msgSeq - lastSeq - 1; if (missing != 0) { for (long j = lastSeq + 1; j < msgSeq; j++) { missingIds.add(String.valueOf(j)); } System.err.println("*** Sequence error: current=" + msgSeq + " previous=" + lastSeq + " Missing=" + missing); } } lastSeq = msgSeq; } } if (printHash) { System.err.print("."); } return true; } public void close() throws IOException { if (bw != null) { bw.close(); } } } }