imapfolder.java

此源码是在sun站点上提供的javamail基础上改进。用来解决中文邮件或很多国际间邮件乱码问题。版权属于sun公司。不过当你开发webmail程序时做邮件展示时

		} finally {
                    releaseStoreProtocol(p);
                }
	    } catch (ConnectionException cex) {
                throw new StoreClosedException(store, cex.getMessage());
	    } catch (ProtocolException pex) {
		throw new MessagingException(pex.getMessage(), pex);
	    }
	}

	// Folder is open, we know what the total message count is ..
	synchronized(messageCacheLock) {
	    // tickle the folder and store connections.
	    try {
		keepConnectionAlive(true);
		return total;
	    } catch (ConnectionException cex) {
		throw new FolderClosedException(this, cex.getMessage());
	    } catch (ProtocolException pex) {
		throw new MessagingException(pex.getMessage(), pex);
	    }
	}
    }

    /**
     * Get the new message count.
     */
    public synchronized int getNewMessageCount()
			throws MessagingException {
	if (!opened) {
	    checkExists();
	    // If this folder is not yet open, we use STATUS to
	    // get the new message count
	    try {
		Status status = getStatus();
		return status.recent;
	    } catch (BadCommandException bex) {
		// doesn't support STATUS, probably vanilla IMAP4 ..
		// lets try EXAMINE
                IMAPProtocol p = null;

	        try {
	            p = getStoreProtocol();	// XXX
		    MailboxInfo minfo = p.examine(fullName);
		    p.close();
		    return minfo.recent;
		} catch (ProtocolException pex) {
		    // Give up.
		    throw new MessagingException(pex.getMessage(), pex);
		} finally {
                    releaseStoreProtocol(p);
                }
	    } catch (ConnectionException cex) {
		throw new StoreClosedException(store, cex.getMessage());
	    } catch (ProtocolException pex) {
		throw new MessagingException(pex.getMessage(), pex);
	    }
	}

	// Folder is open, we know what the new message count is ..
	synchronized(messageCacheLock) {
	    // tickle the folder and store connections.
	    try {
		keepConnectionAlive(true);
		return recent;
	    } catch (ConnectionException cex) {
		throw new FolderClosedException(this, cex.getMessage());
	    } catch (ProtocolException pex) {
		throw new MessagingException(pex.getMessage(), pex);
	    }
	}
    }

    /**
     * Get the unread message count.
     */
    public synchronized int getUnreadMessageCount()
			throws MessagingException {
	if (!opened) {
	    checkExists();
	    // If this folder is not yet open, we use STATUS to
	    // get the unseen message count
	    try {
		Status status = getStatus();
		return status.unseen;
	    } catch (BadCommandException bex) {
		// doesn't support STATUS, probably vanilla IMAP4 ..
		// Could EXAMINE, SEARCH for UNREAD messages and
		// return the count .. bah, not worth it.
		return -1;
	    } catch (ConnectionException cex) {
		throw new StoreClosedException(store, cex.getMessage());
	    } catch (ProtocolException pex) {
		throw new MessagingException(pex.getMessage(), pex);
	    }
	}

	// if opened, issue server-side search for messages that do
	// *not* have the SEEN flag.
	Flags f = new Flags();
	f.add(Flags.Flag.SEEN);
	try {
	    synchronized(messageCacheLock) {
		int[] matches = getProtocol().search(new FlagTerm(f, false));
		return matches.length; // NOTE: 'matches' is never null
	    }
	} catch (ConnectionException cex) {
	    throw new FolderClosedException(this, cex.getMessage());
	} catch (ProtocolException pex) {
	    // Shouldn't happen
	    throw new MessagingException(pex.getMessage(), pex);
	}
    }

    /**
     * Get the deleted message count.
     */
    public synchronized int getDeletedMessageCount()
			throws MessagingException {
	if (!opened) {
	    checkExists();
	    // no way to do this on closed folders
	    return -1;
	}

	// if opened, issue server-side search for messages that do
	// have the DELETED flag.
	Flags f = new Flags();
	f.add(Flags.Flag.DELETED);
	try {
	    synchronized(messageCacheLock) {
		int[] matches = getProtocol().search(new FlagTerm(f, true));
		return matches.length; // NOTE: 'matches' is never null
	    }
	} catch (ConnectionException cex) {
	    throw new FolderClosedException(this, cex.getMessage());
	} catch (ProtocolException pex) {
	    // Shouldn't happen
	    throw new MessagingException(pex.getMessage(), pex);
	}
    }

    /*
     * Get results of STATUS command for this folder, checking cache first.
     * ASSERT: Must be called with this folder's synchronization lock held.
     * ASSERT: The folder must be closed.
     */
    private Status getStatus() throws ProtocolException {
	int statusCacheTimeout = ((IMAPStore)store).getStatusCacheTimeout();

	// if allowed to cache and our cache is still valid, return it
	if (statusCacheTimeout > 0 && cachedStatus != null &&
	    System.currentTimeMillis() - cachedStatusTime < statusCacheTimeout)
	    return cachedStatus;

        IMAPProtocol p = null;

	try {
	    p = getStoreProtocol();	// XXX
	    Status s = p.status(fullName, null); 
	    // if allowed to cache, do so
	    if (statusCacheTimeout > 0) {
		cachedStatus = s;
		cachedStatusTime = System.currentTimeMillis();
	    }
	    return s;
        } finally {
            releaseStoreProtocol(p);
        }
    }

    /**
     * Get the specified message.
     */
    public synchronized Message getMessage(int msgnum) 
		throws MessagingException {
	checkOpened();
	checkRange(msgnum);

	return (Message)messageCache.elementAt(msgnum-1);
    }

    /**
     * Append the given messages into this folder.
     */
    public synchronized void appendMessages(Message[] msgs)
				throws MessagingException {
	checkExists(); // verify that self exists

	// XXX - have to verify that messages are in a different
	// store (if any) than target folder, otherwise could
	// deadlock trying to fetch messages on the same connection
	// we're using for the append.

	int maxsize = ((IMAPStore)store).getAppendBufferSize();

	for (int i = 0; i < msgs.length; i++) {
	    final Message m = msgs[i];
	    final MessageLiteral mos;

	    try {
		// if we know the message is too big, don't buffer any of it
		mos = new MessageLiteral(m,
				m.getSize() > maxsize ? 0 : maxsize);
	    } catch (IOException ex) {
		throw new MessagingException(
				"IOException while appending messages", ex);
	    } catch (MessageRemovedException mrex) {
		continue; // just skip this expunged message
	    }

	    Date d = m.getReceivedDate(); // retain dates
	    if (d == null)
		d = m.getSentDate();
	    final Date dd = d;
	    final Flags f = m.getFlags();
	    doCommand(new ProtocolCommand() {
		public Object doCommand(IMAPProtocol p)
			throws ProtocolException {
		    p.append(fullName, f, dd, mos);
		    return null;
		}
	    });
	}
    }

    /**
     * Append the given messages into this folder.
     * Return array of AppendUID objects containing
     * UIDs of these messages in the destination folder.
     * Each element of the returned array corresponds to
     * an element of the <code>msgs</code> array.  A null
     * element means the server didn't return UID information
     * for the appended message.  <p>
     *
     * Depends on the APPENDUID response code defined by the
     * UIDPLUS extension -
     * <A HREF="http://www.ietf.org/rfc/rfc2359.txt">RFC 2359</A>.
     *
     * @since	JavaMail 1.4
     */
    public synchronized AppendUID[] appendUIDMessages(Message[] msgs)
				throws MessagingException {
	checkExists(); // verify that self exists

	// XXX - have to verify that messages are in a different
	// store (if any) than target folder, otherwise could
	// deadlock trying to fetch messages on the same connection
	// we're using for the append.

	int maxsize = ((IMAPStore)store).getAppendBufferSize();

	AppendUID[] uids = new AppendUID[msgs.length];
	for (int i = 0; i < msgs.length; i++) {
	    final Message m = msgs[i];
	    final MessageLiteral mos;

	    try {
		// if we know the message is too big, don't buffer any of it
		mos = new MessageLiteral(m,
				m.getSize() > maxsize ? 0 : maxsize);
	    } catch (IOException ex) {
		throw new MessagingException(
				"IOException while appending messages", ex);
	    } catch (MessageRemovedException mrex) {
		continue; // just skip this expunged message
	    }

	    Date d = m.getReceivedDate(); // retain dates
	    if (d == null)
		d = m.getSentDate();
	    final Date dd = d;
	    final Flags f = m.getFlags();
	    AppendUID auid = (AppendUID)doCommand(new ProtocolCommand() {
		public Object doCommand(IMAPProtocol p)
			throws ProtocolException {
		    return p.appenduid(fullName, f, dd, mos);
		}
	    });
	    uids[i] = auid;
	}
	return uids;
    }

    /**
     * Append the given messages into this folder.
     * Return array of Message objects representing
     * the messages in the destination folder.  Note
     * that the folder must be open.
     * Each element of the returned array corresponds to
     * an element of the <code>msgs</code> array.  A null
     * element means the server didn't return UID information
     * for the appended message. <p>
     *
     * Depends on the APPENDUID response code defined by the
     * UIDPLUS extension -
     * <A HREF="http://www.ietf.org/rfc/rfc2359.txt">RFC 2359</A>.
     *
     * @since	JavaMail 1.4
     */
    public synchronized Message[] addMessages(Message[] msgs)
				throws MessagingException {
	checkOpened();
	Message[] rmsgs = new MimeMessage[msgs.length];
	AppendUID[] uids = appendUIDMessages(msgs);
	for (int i = 0; i < uids.length; i++) {
	    AppendUID auid = uids[i];
	    if (auid != null) {
		if (auid.uidvalidity == uidvalidity) {
		    try {
			rmsgs[i] = getMessageByUID(auid.uid);
		    } catch (MessagingException mex) {
			// ignore errors at this stage
		    }
		}
	    }
	}
	return rmsgs;
    }

    /**
     * Copy the specified messages from this folder, to the
     * specified destination.
     */
    public synchronized void copyMessages(Message[] msgs, Folder folder)
			throws MessagingException {
	checkOpened();

	if (msgs.length == 0) // boundary condition
	    return;

	// If the destination belongs to our same store, optimize
	if (folder.getStore() == store) {
	    synchronized(messageCacheLock) {
		try {
		    IMAPProtocol p = getProtocol();
		    MessageSet[] ms = Utility.toMessageSet(msgs, null);
		    if (ms == null)
			throw new MessageRemovedException(
					"Messages have been removed");
		    p.copy(ms, folder.getFullName());
		} catch (CommandFailedException cfx) {
		    if (cfx.getMessage().indexOf("TRYCREATE") != -1)
			throw new FolderNotFoundException(
                            folder,
			    folder.getFullName() + " does not exist"
			   );
		    else 
			throw new MessagingException(cfx.getMessage(), cfx);
		} catch (ConnectionException cex) {
		    throw new FolderClosedException(this, cex.getMessage());
		} catch (ProtocolException pex) {
		    throw new MessagingException(pex.getMessage(), pex);
	    	}
	    }
	} else // destination is a different store.
	    super.copyMessages(msgs, folder);
    }

    /**
     * Expunge all messages marked as DELETED.
     */
    public synchronized Message[] expunge() throws MessagingException {
	return expunge(null);
    }

    /**
     * Expunge the indicated messages, which must have been marked as DELETED.
     */
    public synchronized Message[] expunge(Message[] msgs)
				throws MessagingException {
	checkOpened();

	Vector v = new Vector(); // to collect expunged messages

	if (msgs != null) {
	    // call fetch to make sure we have all the UIDs
	    FetchProfile fp = new FetchProfile();
	    fp.add(UIDFolder.FetchProfileItem.UID);
	    fetch(msgs, fp);
	}

	synchronized(messageCacheLock) {
	    doExpungeNotification = false; // We do this ourselves later
	    try {
		IMAPProtocol p = getProtocol();
		if (msgs != null)
		    p.uidexpunge(Utility.toUIDSet(msgs));
		else
		    p.expunge();
	    } catch (CommandFailedException cfx) {
		// expunge not allowed, perhaps due to a permission problem?
		if (mode != READ_WRITE)
		    throw new IllegalStateException(
			"Cannot expunge READ_ONLY folder: " + fullName);
		else
		    throw new MessagingException(cfx.getMessage(), cfx);
	    } catch (ConnectionException cex) {
		throw new FolderClosedException(this, cex.getMessage());
	    } catch (ProtocolException pex) {