nntpstore.java

java 开发的一个电子邮局,挺实用的

						throw new MessagingException(command+" failed: "+response);
					}
				} catch (IOException e) {
					throw new MessagingException(command+" failed", e);
				} catch (NumberFormatException e) {
					throw new MessagingException(command+" failed", e);
				}
				overviewFormat = new String[vector.size()]; vector.copyInto(overviewFormat);
				strippedOverviewFormat = new String[vector2.size()]; vector2.copyInto(strippedOverviewFormat);
				if (session.getDebug()) {
					StringBuffer buffer = new StringBuffer();
					buffer.append("DEBUG: nntp: overview format: ");
					for (int i=0; i<strippedOverviewFormat.length;i++) {
						if (i>0)
							buffer.append(", ");
						buffer.append(strippedOverviewFormat[i]);
					}
					System.out.println(buffer.toString());
				}
			}
		}
		if (strip)
			return strippedOverviewFormat;
		else
			return overviewFormat;
	}

    // Prefetches header information for the specified messages, if possible
	Article[] getOverview(Newsgroup newsgroup) throws MessagingException {
        String name = newsgroup.getName();
        String[] format = getOverviewFormat(false);
		String command = "GROUP "+name;
		if (current==null || !name.equals(current.getName())) { // select the group
			synchronized (this) {
				try {
					send(command);
					switch (getResponse()) {
					  case GROUP_SELECTED:
						try {
							updateGroup(newsgroup, response);
							current = newsgroup;
						} catch(NumberFormatException e) {
							throw new MessagingException("NNTP protocol exception: "+response, e);
						}
					  case NO_SUCH_GROUP:
						throw new MessagingException("No such group");
					  case SERVER_ERROR:
						if (response.toLowerCase().indexOf("timeout")>-1) {
							close();
							connect();
							return getOverview(newsgroup);
						}
					  default:
						throw new MessagingException(command+" failed: "+response);
					}
				} catch (IOException e) {
					throw new MessagingException(command+" failed", e);
				}
			}
		}
		command = "XOVER "+newsgroup.first+"-"+newsgroup.last;
		Vector av = new Vector(Math.max(newsgroup.last-newsgroup.first, 10));
		synchronized (this) {
			try {
				send(command);
				switch (getResponse()) {
				  case LISTING_OVERVIEW:
					String line;
					int count = 0, length = (newsgroup.last-newsgroup.first);
					processStatusEvent(new StatusEvent(this, StatusEvent.OPERATION_START, "Retrieving messages", 0, length, 0));
					for (line=in.readLine(); line!=null && !".".equals(line); line = in.readLine()) {
						int tabIndex = line.indexOf('\t');
						if (tabIndex>-1) {
							int msgnum = Integer.parseInt(line.substring(0, tabIndex));
                            Article article = new Article(newsgroup, msgnum);
							article.addXoverHeaders(getOverviewHeaders(format, line, tabIndex));
							av.addElement(article);
						} else
							throw new ProtocolException("Invalid overview line format");
						if ((++count%50) == 0)
							processStatusEvent(new StatusEvent(this, StatusEvent.OPERATION_UPDATE, "Retrieved "+count+" of "+length+" messages", 0, length, count));
					}
					processStatusEvent(new StatusEvent(this, StatusEvent.OPERATION_END, "Done", 0, length, length));
					break;
				  case NO_ARTICLE_SELECTED:
				  case PERMISSION_DENIED:
					break;
				  case NO_GROUP_SELECTED:
				  case SERVER_ERROR:
				  default:
					throw new MessagingException(command+" failed: "+response);
				}
			} catch (IOException e) {
				throw new MessagingException(command+" failed", e);
			} catch (NumberFormatException e) {
				throw new MessagingException(command+" failed", e);
			}
		}
		Article[] articles = new Article[av.size()]; av.copyInto(articles);
		return articles;
	}

    // Returns an InternetHeaders object representing the headers stored in an xover response line.
	InternetHeaders getOverviewHeaders(String[] format, String line, int startIndex) {
        InternetHeaders headers = new InternetHeaders();
		for (int i=0; i<format.length; i++) {
			int colonIndex = format[i].indexOf(':');
			String key = format[i].substring(0, colonIndex);
			boolean full = "full".equals(format[i].substring(colonIndex+1, format[i].length()));
			int tabIndex = line.indexOf('\t', startIndex+1);
			if (tabIndex<0) tabIndex = line.length();
			String value = line.substring(startIndex+1, tabIndex);
			if (full)
				value = value.substring(value.indexOf(':')+1).trim();
			headers.addHeader(key, value);
			startIndex = tabIndex;
		}
		return headers;
	}

	boolean validateOverviewHeader(String key) throws MessagingException {
		String[] format = getOverviewFormat(true);
		for (int i=0; i<format.length; i++) {
			if (key.equalsIgnoreCase(format[i]))
				return true;
		}
		return false;
	}

	public void addStatusListener(StatusListener l) {
		synchronized (statusListeners) {
			statusListeners.addElement(l);
		}
	}
			
	public void removeStatusListener(StatusListener l) {
		synchronized (statusListeners) {
			statusListeners.removeElement(l);
		}
	}
			
	protected void processStatusEvent(StatusEvent event) {
        StatusListener[] listeners;
		synchronized (statusListeners) {
			listeners = new StatusListener[statusListeners.size()];
			statusListeners.copyInto(listeners);
		}
		switch (event.getType()) {
		  case StatusEvent.OPERATION_START:
			for (int i=0; i<listeners.length; i++)
				listeners[i].statusOperationStarted(event);
			break;
		  case StatusEvent.OPERATION_UPDATE:
			for (int i=0; i<listeners.length; i++)
				listeners[i].statusProgressUpdate(event);
			break;
		  case StatusEvent.OPERATION_END:
			for (int i=0; i<listeners.length; i++)
				listeners[i].statusOperationEnded(event);
            break;
		}
	}

	/*
	 * Manages multiplexing of store connections.
	 */
	static Hashtable stores;
	
	static void addStore(NNTPStore store) {
		if (stores==null)
			stores = new Hashtable();
		stores.put(store.socket, store);
	}
	
	static void removeStore(NNTPStore store) {
		stores.remove(store.socket);
	}
	
	static NNTPStore getStore(InetAddress address, int port) {
		if (stores==null)
			return null;
		for (Enumeration enum = stores.keys(); enum.hasMoreElements(); ) {
			Socket ss = (Socket)enum.nextElement();
			InetAddress sa = ss.getInetAddress();
			int sp = ss.getPort();
			if (sp==port && sa.equals(address))
				return (NNTPStore)stores.get(ss);
		}
		return null;
	}
	
	/**
	 * The root holds the newsgroups in an NNTPStore.
	 */
	class Root extends Folder {

		/**
		 * Constructor.
		 */
		protected Root(Store store) { super(store); }

		/**
		 * Returns the name of this folder.
		 */
		public String getName() { return "/"; }

		/**
		 * Returns the full name of this folder.
		 */
		public String getFullName() { return getName(); }

		/**
		 * Returns the type of this folder.
		 */
		public int getType() throws MessagingException { return HOLDS_FOLDERS; }

		/**
		 * Indicates whether this folder exists.
		 */
		public boolean exists() throws MessagingException { return true; }

		/**
		 * Indicates whether this folder contains any new articles.
		 */
		public boolean hasNewMessages() throws MessagingException { return false; }

		/**
		 * Opens this folder.
		 */
		public void open(int mode) throws MessagingException {
			if (mode!=this.READ_ONLY) throw new MessagingException("Folder is read-only");
		}

		/**
		 * Closes this folder.
		 */
		public void close(boolean expunge) throws MessagingException {}

		/**
		 * Expunges this folder.
		 */
		public Message[] expunge() throws MessagingException { return new Message[0]; }

		/**
		 * Indicates whether this folder is open.
		 */
		public boolean isOpen() { return true; }

		/**
		 * Returns the permanent flags for this folder.
		 */
		public Flags getPermanentFlags() { return new Flags(); }
	
		/**
		 * Returns the number of articles in this folder.
		 */
		public int getMessageCount() throws MessagingException { return 0; }

		/**
		 * Returns the articles in this folder.
		 */
		public Message[] getMessages() throws MessagingException {
			throw new MessagingException("Folder can't contain messages");
		}
	
		/**
		 * Returns the specified message in this folder.
		 * Since NNTP articles are not stored in sequential order,
		 * the effect is just to reference articles returned by getMessages().
		 */
		public Message getMessage(int msgnum) throws MessagingException {
			throw new MessagingException("Folder can't contain messages");
		}
	
		/**
		 * Root folder is read-only.
		 */
		public void appendMessages(Message aarticle[]) throws MessagingException {
			throw new MessagingException("Folder is read-only");
		}

		/**
		 * Does nothing.
		 */
		public void fetch(Message articles[], FetchProfile fetchprofile) throws MessagingException {
		}

		/**
		 * This folder does not have a parent.
		 */
		public Folder getParent() throws MessagingException { return null; }

		/**
		 * Returns the newsgroups on the server.
		 */
		public Folder[] list() throws MessagingException {
			return getNewsgroups("LIST ACTIVE", false);
		}

		/**
		 * Returns the newsgroups on the server.
		 */
		public Folder[] list(String pattern) throws MessagingException {
			return getNewsgroups(pattern, false);
		}

		/**
		 * Returns the subscribed newsgroups on the server.
		 */
		public Folder[] listSubscribed() throws MessagingException {
			Vector groups = new Vector();
			for (Enumeration enum = newsgroups.elements(); enum.hasMoreElements(); ) {
				Newsgroup group = (Newsgroup)enum.nextElement();
				if (group.subscribed)
					groups.addElement(group);
			}
			Folder[] list = new Folder[groups.size()]; groups.copyInto(list);
			return list;
		}

		/**
		 * Returns the subscribed newsgroups on the server.
		 */
		public Folder[] listSubscribed(String pattern) throws MessagingException {
			return listSubscribed();
		}

		/**
		 * Returns the newsgroup with the specified name.
		 */
		public Folder getFolder(String name) throws MessagingException {
			return getNewsgroup(name);
		}

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

		/**
		 * Root folders cannot be created, deleted, or renamed.
		 */
		public boolean create(int i) throws MessagingException {
			throw new MessagingException("Folder cannot be created");
		}

		/**
		 * Root folders cannot be created, deleted, or renamed.
		 */
		public boolean delete(boolean flag) throws MessagingException {
			throw new MessagingException("Folder cannot be deleted");
		}

		/**
		 * Root folders cannot be created, deleted, or renamed.
		 */
		public boolean renameTo(Folder folder) throws MessagingException {
			throw new MessagingException("Folder cannot be renamed");
		}

	}
	
}