imapprotocol.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

	    handleResult(response);
	    return null;
	}
    }

    /**
     * Partial FETCH of given BODY section, without setting SEEN flag.
     */
    public BODY peekBody(int msgno, String section, int start, int size)
			throws ProtocolException {
	return fetchBody(msgno, section, start, size, true, null);
    }

    /**
     * Partial FETCH of given BODY section.
     */
    public BODY fetchBody(int msgno, String section, int start, int size)
			throws ProtocolException {
	return fetchBody(msgno, section, start, size, false, null);
    }

    /**
     * Partial FETCH of given BODY section, without setting SEEN flag.
     */
    public BODY peekBody(int msgno, String section, int start, int size,
				ByteArray ba) throws ProtocolException {
	return fetchBody(msgno, section, start, size, true, ba);
    }

    /**
     * Partial FETCH of given BODY section.
     */
    public BODY fetchBody(int msgno, String section, int start, int size,
				ByteArray ba) throws ProtocolException {
	return fetchBody(msgno, section, start, size, false, ba);
    }

    protected BODY fetchBody(int msgno, String section, int start, int size,
			boolean peek, ByteArray ba) throws ProtocolException {
	this.ba = ba;	// save for later use by getResponseBuffer
	Response[] r = fetch(
			msgno, (peek ? "BODY.PEEK[" : "BODY[" ) +
			(section == null ? "]<" : (section +"]<")) +
			String.valueOf(start) + "." +
			String.valueOf(size) + ">"
		       );

	notifyResponseHandlers(r);

	Response response = r[r.length-1];
	if (response.isOK())
	    return (BODY)FetchResponse.getItem(r, msgno, BODY.class);
	else if (response.isNO())
	    return null;
	else {
	    handleResult(response);
	    return null;
	}
    }

    /**
     * Return a buffer to read a response into.
     * The buffer is provided by fetchBody and is
     * used only once.
     */
    protected ByteArray getResponseBuffer() {
	ByteArray ret = ba;
	ba = null;
	return ret;
    }

    /**
     * Fetch the specified RFC822 Data item. 'what' names
     * the item to be fetched. 'what' can be <code>null</code>
     * to fetch the whole message.
     */
    public RFC822DATA fetchRFC822(int msgno, String what)
			throws ProtocolException {
	Response[] r = fetch(msgno,
			     what == null ? "RFC822" : "RFC822." + what
			    );

	// dispatch untagged responses
	notifyResponseHandlers(r);

	Response response = r[r.length-1]; 
	if (response.isOK())
	    return (RFC822DATA)FetchResponse.getItem(r, msgno, 
					RFC822DATA.class);
	else if (response.isNO())
	    return null;
	else {
	    handleResult(response);
	    return null;
	}
    }

    /**
     * Fetch the FLAGS for the given message.
     */
    public Flags fetchFlags(int msgno) throws ProtocolException {
	Flags flags = null;
	Response[] r = fetch(msgno, "FLAGS");

	// Search for our FLAGS response
	for (int i = 0, len = r.length; i < len; i++) {
	    if (r[i] == null ||
		!(r[i] instanceof FetchResponse) ||
		((FetchResponse)r[i]).getNumber() != msgno)
		continue;		
	    
	    FetchResponse fr = (FetchResponse)r[i];
	    if ((flags = (Flags)fr.getItem(Flags.class)) != null) {
		r[i] = null; // remove this response
		break;
	    }
	}

	// dispatch untagged responses
	notifyResponseHandlers(r);
	handleResult(r[r.length-1]);
	return flags;
    }

    /**
     * Fetch the IMAP UID for the given message.
     */
    public UID fetchUID(int msgno) throws ProtocolException {
	Response[] r = fetch(msgno, "UID");

	// dispatch untagged responses
	notifyResponseHandlers(r);

	Response response = r[r.length-1]; 
	if (response.isOK())
	    return (UID)FetchResponse.getItem(r, msgno, UID.class);
	else if (response.isNO()) // XXX: Issue NOOP ?
	    return null;
	else {
	    handleResult(response);
	    return null; // NOTREACHED
	}
    }
		
    /**
     * Get the sequence number for the given UID. A UID object
     * containing the sequence number is returned. If the given UID
     * is invalid, <code>null</code> is returned.
     */
    public UID fetchSequenceNumber(long uid) throws ProtocolException {
	UID u = null;
	Response[] r = fetch(String.valueOf(uid), "UID", true);	

	for (int i = 0, len = r.length; i < len; i++) {
	    if (r[i] == null || !(r[i] instanceof FetchResponse))
		continue;
	    
	    FetchResponse fr = (FetchResponse)r[i];
	    if ((u = (UID)fr.getItem(UID.class)) != null) {
		if (u.uid == uid) // this is the one we want
		    break;
		else
		    u = null;
	    }
	}
		
	notifyResponseHandlers(r);
	handleResult(r[r.length-1]);
	return u;
    }

    /**
     * Get the sequence numbers for UIDs ranging from start till end.
     * UID objects that contain the sequence numbers are returned.
     * If no UIDs in the given range are found, an empty array is returned.
     */
    public UID[] fetchSequenceNumbers(long start, long end)
			throws ProtocolException {
	Response[] r = fetch(String.valueOf(start) + ":" + 
				(end == UIDFolder.LASTUID ? "*" : 
				String.valueOf(end)),
			     "UID", true);	

	UID u;
	Vector v = new Vector();
	for (int i = 0, len = r.length; i < len; i++) {
	    if (r[i] == null || !(r[i] instanceof FetchResponse))
		continue;
	    
	    FetchResponse fr = (FetchResponse)r[i];
	    if ((u = (UID)fr.getItem(UID.class)) != null)
		v.addElement(u);
	}
		
	notifyResponseHandlers(r);
	handleResult(r[r.length-1]);

	UID[] ua = new UID[v.size()];
	v.copyInto(ua);
	return ua;
    }

    /**
     * Get the sequence numbers for UIDs ranging from start till end.
     * UID objects that contain the sequence numbers are returned.
     * If no UIDs in the given range are found, an empty array is returned.
     */
    public UID[] fetchSequenceNumbers(long[] uids) throws ProtocolException {
	StringBuffer sb = new StringBuffer();
	for (int i = 0; i < uids.length; i++) {
	    if (i > 0)
		sb.append(",");
	    sb.append(String.valueOf(uids[i]));
	}

	Response[] r = fetch(sb.toString(), "UID", true);	

	UID u;
	Vector v = new Vector();
	for (int i = 0, len = r.length; i < len; i++) {
	    if (r[i] == null || !(r[i] instanceof FetchResponse))
		continue;
	    
	    FetchResponse fr = (FetchResponse)r[i];
	    if ((u = (UID)fr.getItem(UID.class)) != null)
		v.addElement(u);
	}
		
	notifyResponseHandlers(r);
	handleResult(r[r.length-1]);

	UID[] ua = new UID[v.size()];
	v.copyInto(ua);
	return ua;
    }

    public Response[] fetch(MessageSet[] msgsets, String what)
			throws ProtocolException {
	return fetch(MessageSet.toString(msgsets), what, false);
    }

    public Response[] fetch(int start, int end, String what)
			throws ProtocolException {
	return fetch(String.valueOf(start) + ":" + String.valueOf(end), 
		     what, false);
    }

    public Response[] fetch(int msg, String what) 
			throws ProtocolException {
	return fetch(String.valueOf(msg), what, false);
    }

    private Response[] fetch(String msgSequence, String what, boolean uid)
			throws ProtocolException {
	if (uid)
	    return command("UID FETCH " + msgSequence +" (" + what + ")",null);
	else
	    return command("FETCH " + msgSequence + " (" + what + ")", null);
    }

    /**
     * COPY command.
     */
    public void copy(MessageSet[] msgsets, String mbox)
			throws ProtocolException {
	copy(MessageSet.toString(msgsets), mbox);
    }

    public void copy(int start, int end, String mbox)
			throws ProtocolException {
	copy(String.valueOf(start) + ":" + String.valueOf(end),
		    mbox);
    }

    private void copy(String msgSequence, String mbox)
			throws ProtocolException {
	// encode the mbox as per RFC2060
	mbox = BASE64MailboxEncoder.encode(mbox);

	Argument args = new Argument();	
	args.writeAtom(msgSequence);
	args.writeString(mbox);

	simpleCommand("COPY", args);
    }
		    
    public void storeFlags(MessageSet[] msgsets, Flags flags, boolean set)
			throws ProtocolException {
	storeFlags(MessageSet.toString(msgsets), flags, set);
    }

    public void storeFlags(int start, int end, Flags flags, boolean set)
			throws ProtocolException {
	storeFlags(String.valueOf(start) + ":" + String.valueOf(end),
		   flags, set);
    }

    /**
     * Set the specified flags on this message. <p>
     */
    public void storeFlags(int msg, Flags flags, boolean set)
			throws ProtocolException { 
	storeFlags(String.valueOf(msg), flags, set);
    }

    private void storeFlags(String msgset, Flags flags, boolean set)
			throws ProtocolException {
	Response[] r;
	if (set)
	    r = command("STORE " + msgset + " +FLAGS " + 
			 createFlagList(flags), null);
	else
	    r = command("STORE " + msgset + " -FLAGS " + 
			createFlagList(flags), null);
	
	// Dispatch untagged responses
	notifyResponseHandlers(r);
	handleResult(r[r.length-1]);
    }

    /**
     * Creates an IMAP flag_list from the given Flags object.
     */
    private String createFlagList(Flags flags) {
	StringBuffer sb = new StringBuffer();
	sb.append("("); // start of flag_list

	Flags.Flag[] sf = flags.getSystemFlags(); // get the system flags
	boolean first = true;
	for (int i = 0; i < sf.length; i++) {
	    String s;
	    Flags.Flag f = sf[i];
	    if (f == Flags.Flag.ANSWERED)
		s = "\\Answered";
	    else if (f == Flags.Flag.DELETED)
		s = "\\Deleted";
	    else if (f == Flags.Flag.DRAFT)
		s = "\\Draft";
	    else if (f == Flags.Flag.FLAGGED)
		s = "\\Flagged";
	    else if (f == Flags.Flag.RECENT)
		s = "\\Recent";
	    else if (f == Flags.Flag.SEEN)
		s = "\\Seen";
	    else
		continue;	// skip it
	    if (first)
		first = false;
	    else
		sb.append(' ');
	    sb.append(s);
	}

	String[] uf = flags.getUserFlags(); // get the user flag strings
	for (int i = 0; i < uf.length; i++) {
	    if (first)
		first = false;
	    else
		sb.append(' ');
	    sb.append(uf[i]);
	}

	sb.append(")"); // terminate flag_list
	return sb.toString();
    }

    /**
     * Issue the given search criterion on the specified message sets.
     * Returns array of matching sequence numbers. An empty array
     * is returned if no matches are found.
     *
     * @param	msgsets	array of MessageSets
     * @param	term	SearchTerm
     * @return	array of matching sequence numbers.
     */
    public int[] search(MessageSet[] msgsets, SearchTerm term)
			throws ProtocolException, SearchException {
	return search(MessageSet.toString(msgsets), term);
    }

    /**
     * Issue the given search criterion on all messages in this folder.
     * Returns array of matching sequence numbers. An empty array
     * is returned if no matches are found.
     *
     * @param	term	SearchTerm
     * @return	array of matching sequence numbers.
     */
    public int[] search(SearchTerm term) 
			throws ProtocolException, SearchException {
	return search("ALL", term);
    }

    /* Apply the given SearchTerm on the specified sequence.
     * Returns array of matching sequence numbers. Note that an empty
     * array is returned for no matches.
     */
    private int[] search(String msgSequence, SearchTerm term)
			throws ProtocolException, SearchException {
	// Check if the search "text" terms contain only ASCII chars
	if (SearchSequence.isAscii(term)) {
	    try {
		return issueSearch(msgSequence, term, null);
	    } catch (IOException ioex) { /* will not happen */ }
	}
	
	/* The search "text" terms do contain non-ASCII chars. We need to
	 * use SEARCH CHARSET <charset> ...
	 *	The charsets we try to use are UTF-8 and the locale's
	 * default charset. If the server supports UTF-8, great, 
	 * always use it. Else we try to use the default charset.
	 */

	// Cycle thru the list of charsets
	for (int i = 0; i < searchCharsets.length; i++) {
	    if (searchCharsets[i] == null)
		continue;

	    try {
		return issueSearch(msgSequence, term, searchCharsets[i]);
	    } catch (CommandFailedException cfx) {
		/* Server returned NO. For now, I'll just assume that 
		 * this indicates that this charset is unsupported.
		 * We can check the BADCHARSET response code once
		 * that's spec'd into the IMAP RFC ..
		 */
		searchCharsets[i] = null;
		continue;
	    } catch (IOException ioex) {
		/* Charset conversion failed. Try the next one */
		continue;
	    } catch (ProtocolException pex) {
		throw pex;
	    } catch (SearchException sex) {
		throw sex;
	    }
	}

	// No luck.
	throw new SearchException("Search failed");
    }

    /* Apply the given SearchTerm on the specified sequence, using the
     * given charset. <p>
     * Returns array of matching sequence numbers. Note that an empty
     * array is returned for no matches.
     */
    private int[] issueSearch(String msgSequence, SearchTerm term,
      			      String charset) 
	     throws ProtocolException, SearchException, IOException {

	// Generate a search-sequence with the given charset
	Argument args = SearchSequence.generateSequence(term, 
			  charset == null ? null : 
					    MimeUtility.javaCharset(charset)
			);
	args.writeAtom(msgSequence);

	Response[] r;

	if (charset == null) // text is all US-ASCII
	    r = command("SEARCH", args);
	else
	    r = command("SEARCH CHARSET " + charset, args);

	Response response = r[r.length-1];
	int[] matches = null;

	// Grab all SEARCH responses
	if (response.isOK()) { // command succesful
	    Vector v = new Vector();
	    int num;
	    for (int i = 0, len = r.length; i < len; i++) {
		if (!(r[i] instanceof IMAPResponse))
		    continue;

		IMAPResponse ir = (IMAPResponse)r[i];
		// There *will* be one SEARCH response.
		if (ir.keyEquals("SEARCH")) {
		    while ((num = ir.readNumber()) != -1)
			v.addElement(new Integer(num));
		    r[i] = null;
		}
	    }

	    // Copy the vector into 'matches'
	    int vsize = v.size();
	    matches = new int[vsize];
	    for (int i = 0; i < vsize; i++)
		matches[i] = ((Integer)v.elementAt(i)).intValue();
	}

	// dispatch remaining untagged responses
	notifyResponseHandlers(r);
	handleResult(response);
	return matches;
    }

    /**
     * NAMESPACE Command.
     *
     * @see "RFC2342"
     */
    public Namespaces namespace() throws ProtocolException {
	if (!hasCapability("NAMESPACE")) 
	    throw new BadCommandException("NAMESPACE not supported");

	Response[] r = command("NAMESPACE", null);

	Namespaces namespace = null;
	Response response = r[r.length-1];

	// Grab NAMESPACE response
	if (response.isOK()) { // command succesful 
	    for (int i = 0, len = r.length; i < len; i++) {
		if (!(r[i] instanceof IMAPResponse))
		    continue;

		IMAPResponse ir = (IMAPResponse)r[i];
		if (ir.keyEquals("NAMESPACE")) {
		    if (namespace == null)
			namespace = new Namespaces(ir);
		    r[i] = null;
		}
	    }
	}