mboxfolder.java

本系统是用 java 语言实现的一个 Email客户端

		    messagesAdded.add(newMessage);
		}
							    
	    }

	    messages = finalMessages;
	    if (messagesAdded.size() > 0) {
		Message[] n = new Message[messagesAdded.size()]; messagesAdded.copyInto(n);
		notifyMessageAddedListeners(n);
		
		saveMessages();
	    }
	}
    }
	
	// Saves messages to the disk file.
	private void saveMessages() throws MessagingException {
		synchronized (this) {
			if (messages!=null) {
				try {
					Message[] m = new Message[messages.size()];
					messages.copyInto(m);
					// make sure content has been retrieved for all messages
					for (int i=0; i<m.length; i++)
						if (m[i] instanceof MboxMessage)
							((MboxMessage)m[i]).retrieveContent();
				
					OutputStream os = new BufferedOutputStream(getOutputStream());
					MboxOutputStream mos = new MboxOutputStream(os);
					for (int i=0; i<m.length; i++) {
						Address[] f = m[i].getFrom();
						String from = "-";
						if (f.length>0) {
							if (f[0] instanceof InternetAddress)
								from = ((InternetAddress)f[0]).getAddress();
							else
								from = f[0].toString();
						}
						Date date = m[i].getSentDate();
						if (date==null)
							date = m[i].getReceivedDate();
						if (date==null)
							date = new Date();
					
						String top = "From "+from+ " "+df.format(date)+"\n";
						os.write(top.getBytes());
						m[i].writeTo(mos);
						mos.flush();
					}
					os.close();
					fileLastModified = file.lastModified();
				} catch (IOException e) {
					throw new MessagingException("I/O error writing mailbox", e);
				}
			}
		}
	}
	
	public synchronized void appendMessages(Message[] messages) throws MessagingException {
		synchronizeMessages();

		Vector added = new Vector();
		for (int i=0; i<messages.length; i++) {
			if (messages[i] instanceof MimeMessage) {
				MboxMessage message = new MboxMessage(this, (MimeMessage)messages[i], i);
				added.addElement(message);
				this.messages.addElement(message);
			}
		}
		if (added.size()>0) {
			Message[] n = new Message[added.size()]; added.copyInto(n);
			notifyMessageAddedListeners(n);
		}
		saveMessages();
	}

	/**
	 * Does nothing.
	 * The messages <i>must</i> be fetched in their entirety by getMessages() -
	 * this is the nature of the Mbox protocol.
	 * @exception MessagingException ignore
	 */
	public void fetch(Message amessage[], FetchProfile fetchprofile) throws MessagingException {
	}

	/**
	 * Returns the parent folder.
	 */
	public Folder getParent() throws MessagingException {
		return store.getFolder(file.getParent());
	}

	/**
	 * Returns the subfolders of this folder.
	 */
	public Folder[] list() throws MessagingException {
		if (type!=HOLDS_FOLDERS)
			throw new MessagingException("This folder can't contain subfolders");
		try {
			String[] files = file.list();
			Folder[] folders = new Folder[files.length];
			for (int i=0; i<files.length; i++)
				folders[i] = store.getFolder(file.getAbsolutePath()+File.separator+files[i]);
			return folders;
		} catch (SecurityException e) {
			throw new MessagingException("Access denied", e);
		}
	}

	/**
	 * Returns the subfolders of this folder matching the specified pattern.
	 */
    public Folder[] list(String pattern) throws MessagingException {
		if (type!=HOLDS_FOLDERS)
			throw new MessagingException("This folder can't contain subfolders");
		try {
			String[] files = file.list(new MboxFilenameFilter(pattern));
			Folder[] folders = new Folder[files.length];
			for (int i=0; i<files.length; i++)
				folders[i] = store.getFolder(file.getAbsolutePath()+File.separator+files[i]);
			return folders;
		} catch (SecurityException e) {
			throw new MessagingException("Access denied", e);
		}
	}

	/**
	 * Returns the separator character.
	 */
	public char getSeparator() throws MessagingException {
		return File.separatorChar;
	}

	/**
	 * Creates this folder in the store.
	 */
	public boolean create(int type) throws MessagingException {
		if (file.exists())
			throw new MessagingException("Folder already exists");
		switch (type) {
		  case HOLDS_FOLDERS:
			try {
				file.mkdirs();
				this.type = type;
				notifyFolderListeners(FolderEvent.CREATED);
				return true;
			} catch (SecurityException e) {
				throw new MessagingException("Access denied", e);
			}
		  case HOLDS_MESSAGES:
			try {
				// save the changes
				synchronized (this) {
                    if (messages==null) messages = new Vector();
					OutputStream os = new BufferedOutputStream(getOutputStream());
					Message[] m = new Message[messages.size()]; messages.copyInto(m);
					for (int i=0; i<m.length; i++) {
						Address[] f = m[i].getFrom();
						String top = "From "+((f.length>0) ? f[0].toString() : "-")+" "+df.format(m[i].getSentDate())+"\n";
						os.write(top.getBytes());
						m[i].writeTo(os);
					}
					os.close();
				}
				this.type = type;
				notifyFolderListeners(FolderEvent.CREATED);
				return true;
			} catch (IOException e) {
				throw new MessagingException("I/O error writing mailbox", e);
			} catch (SecurityException e) {
				throw new MessagingException("Access denied", e);
			}
		}
		return false;
	}

	/**
	 * Deletes this folder.
	 */
	public boolean delete(boolean recurse) throws MessagingException {
		if (recurse) {
			try {
				if (type==HOLDS_FOLDERS) {
					Folder[] folders = list();
					for (int i=0; i<folders.length; i++)
						if (!folders[i].delete(recurse))
							return false;
				}
				file.delete();
				notifyFolderListeners(FolderEvent.DELETED);
				return true;
			} catch (SecurityException e) {
				throw new MessagingException("Access denied", e);
			}
		} else {
			try {
				if (type==HOLDS_FOLDERS) {
					Folder[] folders = list();
					if (folders.length>0)
						return false;
				}
				file.delete();
				notifyFolderListeners(FolderEvent.DELETED);
				return true;
			} catch (SecurityException e) {
				throw new MessagingException("Access denied", e);
			}
		}
	}

	/**
	 * Mbox folders cannot be created, deleted, or renamed.
	 */
	public boolean renameTo(Folder folder) throws MessagingException {
		try {
            String filename = folder.getFullName();
			if (filename!=null) {
				file.renameTo(new File(filename));
				((MboxStore)store).folders.clear();
				notifyFolderListeners(FolderEvent.RENAMED);
				return true;
			} else
				throw new MessagingException("Illegal filename: null");
		} catch (SecurityException e) {
			throw new MessagingException("Access denied", e);
		}
	}

	/**
	 * Mbox folders cannot contain subfolders.
	 */
	public Folder getFolder(String filename) throws MessagingException {
		return store.getFolder(file.getAbsolutePath()+File.separator+filename);
	}

	/**
	 * Checks if the current file is or is supposed to be
	 * compressed. Uses the filename to figure it out.
	 */
	private boolean isGzip() {
		return file.getName().toLowerCase().endsWith(".gz");
	}

	/**
	 * Creates an output stream that possibly will compress
	 * whatever is sent to it, based on the current filename.
	 */
	private OutputStream getOutputStream() throws IOException {
		OutputStream out;

		out = new FileOutputStream(file);
		if (isGzip())
			out = new GZIPOutputStream(out);
		return out;
	}

    /** 
     * Locks this mailbox.  Not implementented yet.
     */
    public synchronized boolean acquireLock() {
	return true;
    }

    /**
     * Unlocks this mailbox.  Not implemented yet.
     */
    public synchronized boolean releaseLock() {
	return true;
    }

	/**
	 * Creates an input stream that possibly will decompress the
	 * file contents.
	 */
	private InputStream getInputStream() throws IOException {
		InputStream in;

		in = new FileInputStream(file);
		if (isGzip())
			in = new GZIPInputStream(in);
		return in;
	}

	class MboxFilenameFilter implements FilenameFilter {

		String pattern;
		int asteriskIndex, percentIndex;

		MboxFilenameFilter(String pattern) {
			this.pattern = pattern;
			asteriskIndex = pattern.indexOf('*');
			percentIndex = pattern.indexOf('%');
		}
		
		public boolean accept(File directory, String name) {
			if (asteriskIndex>-1) {
				String start = pattern.substring(0, asteriskIndex), end = pattern.substring(asteriskIndex+1, pattern.length());
				return (name.startsWith(start) && name.endsWith(end));
			} else if (percentIndex>-1) {
				String start = pattern.substring(0, percentIndex), end = pattern.substring(percentIndex+1, pattern.length());
				return (directory.equals(file) && name.startsWith(start) && name.endsWith(end));
			}
			return name.equals(pattern);
		}
		
	}

    
}