pop3handler.java

java 开发的邮件服务器平台。支持以下协议。 协议可以修改为自己的专门标识

                        writeLoggedFlushedResponse(responseString);
                    } else {
                        StringBuffer responseBuffer =
                            new StringBuffer(64)
                                    .append(ERR_RESPONSE)
                                    .append(" Message (")
                                    .append(num)
                                    .append(") already deleted.");
                        responseString = responseBuffer.toString();
                        writeLoggedFlushedResponse(responseString);
                    }
                } catch (IndexOutOfBoundsException npe) {
                    StringBuffer responseBuffer =
                        new StringBuffer(64)
                                .append(ERR_RESPONSE)
                                .append(" Message (")
                                .append(num)
                                .append(") does not exist.");
                    responseString = responseBuffer.toString();
                    writeLoggedFlushedResponse(responseString);
                } catch (NumberFormatException nfe) {
                    StringBuffer responseBuffer =
                        new StringBuffer(64)
                                .append(ERR_RESPONSE)
                                .append(" ")
                                .append(argument)
                                .append(" is not a valid number");
                    responseString = responseBuffer.toString();
                    writeLoggedFlushedResponse(responseString);
                }
            }
        } else {
            writeLoggedFlushedResponse(ERR_RESPONSE);
        }
    }

    /**
     * Handler method called upon receipt of a RSET command.
     * Calls stat() to reset the mailbox.
     *
     * @param command the command parsed by the parseCommand method
     * @param argument the first argument parsed by the parseCommand method
     * @param argument1 the second argument parsed by the parseCommand method
     */
    private void doRSET(String command,String argument,String argument1) {
        String responseString = null;
        if (state == TRANSACTION) {
            stat();
            responseString = OK_RESPONSE;
        } else {
            responseString = ERR_RESPONSE;
        }
        writeLoggedFlushedResponse(responseString);
    }

    /**
     * Handler method called upon receipt of a DELE command.
     * This command deletes a particular mail message from the
     * mailbox.
     *
     * @param command the command parsed by the parseCommand method
     * @param argument the first argument parsed by the parseCommand method
     * @param argument1 the second argument parsed by the parseCommand method
     */
    private void doDELE(String command,String argument,String argument1) {
        String responseString = null;
        if (state == TRANSACTION) {
            int num = 0;
            try {
                num = Integer.parseInt(argument);
            } catch (Exception e) {
                responseString = ERR_RESPONSE + " Usage: DELE [mail number]";
                writeLoggedFlushedResponse(responseString);
                return;
            }
            try {
                MailImpl mc = (MailImpl) userMailbox.get(num);
                if (mc == DELETED) {
                    StringBuffer responseBuffer =
                        new StringBuffer(64)
                                .append(ERR_RESPONSE)
                                .append(" Message (")
                                .append(num)
                                .append(") already deleted.");
                    responseString = responseBuffer.toString();
                    writeLoggedFlushedResponse(responseString);
                } else {
                    userMailbox.set(num, DELETED);
                    writeLoggedFlushedResponse(OK_RESPONSE + " Message deleted");
                }
            } catch (IndexOutOfBoundsException iob) {
                StringBuffer responseBuffer =
                    new StringBuffer(64)
                            .append(ERR_RESPONSE)
                            .append(" Message (")
                            .append(num)
                            .append(") does not exist.");
                responseString = responseBuffer.toString();
                writeLoggedFlushedResponse(responseString);
            }
        } else {
            responseString = ERR_RESPONSE;
            writeLoggedFlushedResponse(responseString);
        }
    }

    /**
     * Handler method called upon receipt of a NOOP command.
     * Like all good NOOPs, does nothing much.
     *
     * @param command the command parsed by the parseCommand method
     * @param argument the first argument parsed by the parseCommand method
     * @param argument1 the second argument parsed by the parseCommand method
     */
    private void doNOOP(String command,String argument,String argument1) {
        String responseString = null;
        if (state == TRANSACTION) {
            responseString = OK_RESPONSE;
            writeLoggedFlushedResponse(responseString);
        } else {
            responseString = ERR_RESPONSE;
            writeLoggedFlushedResponse(responseString);
        }
    }

    /**
     * Handler method called upon receipt of a RETR command.
     * This command retrieves a particular mail message from the
     * mailbox.
     *
     * @param command the command parsed by the parseCommand method
     * @param argument the first argument parsed by the parseCommand method
     * @param argument1 the second argument parsed by the parseCommand method
     */
    private void doRETR(String command,String argument,String argument1) {
        String responseString = null;
        if (state == TRANSACTION) {
            int num = 0;
            try {
                num = Integer.parseInt(argument.trim());
            } catch (Exception e) {
                responseString = ERR_RESPONSE + " Usage: RETR [mail number]";
                writeLoggedFlushedResponse(responseString);
                return;
            }
            try {
                MailImpl mc = (MailImpl) userMailbox.get(num);
                if (mc != DELETED) {
                    responseString = OK_RESPONSE + " Message follows";
                    writeLoggedFlushedResponse(responseString);
                    OutputStream nouts =
                            new ExtraDotOutputStream(outs);
                    nouts = new BytesWrittenResetOutputStream(nouts,
                                                              theWatchdog,
                                                              theConfigData.getResetLength());
                    mc.writeMessageTo(nouts);
                    nouts.flush();
                    // TODO: Is this an extra CRLF?
                    out.println();
                    out.println(".");
                    out.flush();
                } else {
                    StringBuffer responseBuffer =
                        new StringBuffer(64)
                                .append(ERR_RESPONSE)
                                .append(" Message (")
                                .append(num)
                                .append(") already deleted.");
                    responseString = responseBuffer.toString();
                    writeLoggedFlushedResponse(responseString);
                }
            } catch (IOException ioe) {
                responseString = ERR_RESPONSE + " Error while retrieving message.";
                writeLoggedFlushedResponse(responseString);
            } catch (MessagingException me) {
                responseString = ERR_RESPONSE + " Error while retrieving message.";
                writeLoggedFlushedResponse(responseString);
            } catch (IndexOutOfBoundsException iob) {
                StringBuffer responseBuffer =
                    new StringBuffer(64)
                            .append(ERR_RESPONSE)
                            .append(" Message (")
                            .append(num)
                            .append(") does not exist.");
                responseString = responseBuffer.toString();
                writeLoggedFlushedResponse(responseString);
            }
        } else {
            responseString = ERR_RESPONSE;
            writeLoggedFlushedResponse(responseString);
        }
    }

    /**
     * Handler method called upon receipt of a TOP command.
     * This command retrieves the top N lines of a specified
     * message in the mailbox.
     *
     * The expected command format is
     *  TOP [mail message number] [number of lines to return]
     *
     * @param command the command parsed by the parseCommand method
     * @param argument the first argument parsed by the parseCommand method
     * @param argument1 the second argument parsed by the parseCommand method
     */
    private void doTOP(String command,String argument,String argument1) {
        String responseString = null;
        if (state == TRANSACTION) {
            int num = 0;
            int lines = 0;
            try {
                num = Integer.parseInt(argument);
                lines = Integer.parseInt(argument1);
            } catch (NumberFormatException nfe) {
                responseString = ERR_RESPONSE + " Usage: TOP [mail number] [Line number]";
                writeLoggedFlushedResponse(responseString);
                return;
            }
            try {
                MailImpl mc = (MailImpl) userMailbox.get(num);
                if (mc != DELETED) {
                    responseString = OK_RESPONSE + " Message follows";
                    writeLoggedFlushedResponse(responseString);
                    for (Enumeration e = mc.getMessage().getAllHeaderLines(); e.hasMoreElements(); ) {
                        out.println(e.nextElement());
                    }
                    out.println();
                    OutputStream nouts =
                            new ExtraDotOutputStream(outs);
                    nouts = new BytesWrittenResetOutputStream(nouts,
                                                              theWatchdog,
                                                              theConfigData.getResetLength());
                    mc.writeContentTo(nouts, lines);
                    nouts.flush();
                    out.println(".");
                    out.flush();
                } else {
                    StringBuffer responseBuffer =
                        new StringBuffer(64)
                                .append(ERR_RESPONSE)
                                .append(" Message (")
                                .append(num)
                                .append(") already deleted.");
                    responseString = responseBuffer.toString();
                    writeLoggedFlushedResponse(responseString);
                }
            } catch (IOException ioe) {
                responseString = ERR_RESPONSE + " Error while retrieving message.";
                writeLoggedFlushedResponse(responseString);
            } catch (MessagingException me) {
                responseString = ERR_RESPONSE + " Error while retrieving message.";
                writeLoggedFlushedResponse(responseString);
            } catch (IndexOutOfBoundsException iob) {
                StringBuffer exceptionBuffer =
                    new StringBuffer(64)
                            .append(ERR_RESPONSE)
                            .append(" Message (")
                            .append(num)
                            .append(") does not exist.");
                responseString = exceptionBuffer.toString();
                writeLoggedFlushedResponse(responseString);
            }
        } else {
            responseString = ERR_RESPONSE;
            writeLoggedFlushedResponse(responseString);
        }
    }

    /**
     * Handler method called upon receipt of a QUIT command.
     * This method handles cleanup of the POP3Handler state.
     *
     * @param command the command parsed by the parseCommand method
     * @param argument the first argument parsed by the parseCommand method
     * @param argument1 the second argument parsed by the parseCommand method
     */
    private void doQUIT(String command,String argument,String argument1) {
        String responseString = null;
        if (state == AUTHENTICATION_READY ||  state == AUTHENTICATION_USERSET) {
            responseString = OK_RESPONSE + " Apache James POP3 Server signing off.";
            writeLoggedFlushedResponse(responseString);
            return;
        }
        List toBeRemoved =  ListUtils.subtract(backupUserMailbox, userMailbox);
        try {
            userInbox.remove(toBeRemoved);
            // for (Iterator it = toBeRemoved.iterator(); it.hasNext(); ) {
            //    MailImpl mc = (MailImpl) it.next();
            //    userInbox.remove(mc.getName());
            //}
            responseString = OK_RESPONSE + " Apache James POP3 Server signing off.";
            writeLoggedFlushedResponse(responseString);
        } catch (Exception ex) {
            responseString = ERR_RESPONSE + " Some deleted messages were not removed";
            writeLoggedFlushedResponse(responseString);
            getLogger().error("Some deleted messages were not removed: " + ex.getMessage());
        }
    }

    /**
     * Handler method called upon receipt of an unrecognized command.
     * Returns an error response and logs the command.
     *
     * @param command the command parsed by the parseCommand method
     * @param argument the first argument parsed by the parseCommand method
     * @param argument1 the second argument parsed by the parseCommand method
     */
    private void doUnknownCmd(String command,String argument,String argument1) {
        writeLoggedFlushedResponse(ERR_RESPONSE);
    }

    /**
     * This method logs at a "DEBUG" level the response string that
     * was sent to the POP3 client.  The method is provided largely
     * as syntactic sugar to neaten up the code base.  It is declared
     * private and final to encourage compiler inlining.
     *
     * @param responseString the response string sent to the client
     */
    private final void logResponseString(String responseString) {
        if (getLogger().isDebugEnabled()) {
            getLogger().debug("Sent: " + responseString);
        }
    }

    /**
     * Write and flush a response string.  The response is also logged.
     * Should be used for the last line of a multi-line response or
     * for a single line response.
     *
     * @param responseString the response string sent to the client
     */
    final void writeLoggedFlushedResponse(String responseString) {
        out.println(responseString);
        out.flush();
        logResponseString(responseString);
    }

    /**
     * Write a response string.  The response is also logged.
     * Used for multi-line responses.
     *
     * @param responseString the response string sent to the client
     */
    final void writeLoggedResponse(String responseString) {
        out.println(responseString);
        logResponseString(responseString);
    }

    /**
     * A private inner class which serves as an adaptor
     * between the WatchdogTarget interface and this
     * handler class.
     */
    private class POP3WatchdogTarget
        implements WatchdogTarget {

        /**
         * @see org.apache.james.util.watchdog.WatchdogTarget#execute()
         */
        public void execute() {
            POP3Handler.this.idleClose();
        }

    }

}