casa

Class KQMLParser

java.lang.Object

casa.KQMLParser

All Implemented Interfaces:

KQML, ML

public class KQMLParser
extends Object
implements KQML

This class is responsible for parsing strings into KQML messages in the form of KQMLmessage objects.

Copyright: Copyright 2003-2014, Knowledge Science Group, University of Calgary. Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation. The Knowledge Science Group makes no representations about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty.

Version:

0.9

Author:

Rob Kremer

See Also:

KQMLmessage

Field Summary

Fields

Modifier and Type	Field and Description
private TokenParser	parser

Fields inherited from interface casa.KQML

ACT, ACTOR, AGENT, BACKSLASH, CLOSE, CONTENT, FROM, IN_REPLY_TO, LANGUAGE, ONTOLOGY, OPEN, QUOTE, RECEIVER, RECEIVERS, REPLY_WITH, SENDER, TO

Fields inherited from interface casa.ML

ACCEPT, ACCEPT_PROPOSAL, ACK, ACTION, ADD_OBSERVER, ADVERTISE, AFFIRMATIVE_REPLY, AGREE, ASSEMBLE, BLANK, CAG_CASA, CANCEL, CD, CFP, CHANGE_MEMBERSHIP, CHAT_MESSAGE, CONCLUDE, CONFIRM, CONSIDER, CONTRACT, CONVERSATION_ID, CREATE, CREATE_CD, CREDITOR, DATA_CASA, DEBTOR, DELETE_CD, DELETE_DATA_CD, DELETE_HISTORY_CD, DELETE_INFO, DESTROY, DISCHARGE, DISCONFIRM, DONE, ENCRYPTION_ALGORITHM, ENTITY, EVALUATE, EVENT, EVENT_ADVERTISEMENT_ADDED, EVENT_ADVERTISEMENT_EVENT, EVENT_ADVERTISEMENT_REMOVED, EVENT_BANNER_CHANGED, EVENT_CD_EVENT, EVENT_CD_NEW_MEMBER, EVENT_CHANGED_COMMANDS, EVENT_CHAT_MESSAGE_RECEIVED, EVENT_CLOSE_PORT, EVENT_DEFERRED_EXECUTION, EVENT_DEFERRED_EXECUTION_DELAYED, EVENT_EXECUTABLE, EVENT_EXITED, EVENT_EXITING, EVENT_FAILED_PERFORMATIVES_UPDATE, EVENT_FIND_INSTANCES, EVENT_GET_CD_PARTICIPANTS, EVENT_GET_DATA_CD, EVENT_GET_HISTORY_CD, EVENT_INSERTED_PERFORMATIVES, EVENT_INVITE_CD, EVENT_JOIN_CD, EVENT_JOIN_CD_FAILED, EVENT_JOIN_CD_REPEATED, EVENT_LAC_EVENT, EVENT_MESSAGE_EVENT, EVENT_MESSAGE_IGNORED, EVENT_MESSAGE_INCOMING, EVENT_MESSAGE_OBSERVED, EVENT_MESSAGE_OUTGOING, EVENT_MESSAGE_PARTICIPANT, EVENT_MESSAGE_RECEIVED, EVENT_MESSAGE_SEND_FAILED, EVENT_MESSAGE_SENT, EVENT_PARTICIPANT_CD, EVENT_POLICY_APPLIED, EVENT_POST_STRING, EVENT_PUT_DATA_CD, EVENT_RECURRING, EVENT_RECURRINGEXECUTABLE, EVENT_REGISTER_INSTANCE, EVENT_REGISTER_INSTANCE_LOCAL, EVENT_REGISTER_INSTANCE_REMOTE, EVENT_REGISTER_TYPE, EVENT_SC_EVENT, EVENT_SC_PERFORM_ACTION, EVENT_SC_START, EVENT_SC_STOP, EVENT_SC_VIOLATION, EVENT_STRATEGY_CHANGED, EVENT_UNREGISTER_INSTANCE, EVENT_UNREGISTER_TYPE, EVENT_UPDATE_URL_CD, EVENT_WITHDRAW_CD, EXECUTE, EXIT, FAILURE, FIND_INSTANCE, FIPA_SL, FORWARD_MESSAGE, GET, GET_ACTS, GET_AGENTS, GET_AGENTS_REGISTERED, GET_AGENTS_RUNNING, GET_CDS, GET_DATA, GET_HISTORY, GET_INFO, GET_MEMBERS, GET_NAME, GET_ONTOLOGY, GET_YELLOW_PAGES, GUI_ACTION_REQUEST, INFORM, INFORM_IF, INFORM_REF, INFORM_USERS_LIST, INVITE_CD, JOIN_CD, KQML, LAC_CLOSING, LANGUAGE_VERSION, MESSAGE_FORWARDED, METHOD_CALL, MONITOR, NACK, NEGATIVE, NEGATIVE_REPLY, NEW_COMMAND, NOT, NOT_UNDERSTOOD, NOTIFY, NOTIFY_COMPLETE, NOTIFY_FAILURE, NULL, OBSERVE, OBSERVE_MEMBERSHIP, OBSERVE_MESSAGES, ONTOLOGY_VERSION, PERFORM, PERFORMATIVE, PERSISTENT_ACTION, PETITION, PHYSICAL_ACT, PING, POSITIVE, PRIORITY, PROPAGATE, PROPOSE, PROXY, PUT_DATA, QUERY_IF, QUERY_IF_REPLY, QUERY_REF, QUERY_REF_REPLY, RECIPIENTS, REFUSE, REGISTER, REGISTER_AGENTTYPE, REGISTER_INSTANCE, REGISTER_YELLOWPAGES, REJECT_PROPOSAL, RELEASE, REMOVE_ADVERTISEMENT, REPLY, REPLY_BY, REPLY_TO, REQUEST, REQUEST_ACK, REQUEST_AKA_MAC_LIST, REQUEST_USER_LIST, REQUEST_WHEN, REQUEST_WHENEVER, RESOLVE_URL, RUN, RUN_AGENT, SAVE_INFO, SEARCH, SECURITY_AGENT_USERS_LIST, SECURITY_AUTHENTICATE, SECURITY_AUTHORIZE, SECURITY_CHECK_ACCESS, SECURITY_VOTE, SENSE, SIGNATURE, SIGNATURE_METHOD, SPECIFIC_AKA_LIST, SUBSCRIBE, SUCCESS, TIME_MESSAGE, TIMEOUT_NEVER, TOP, UNADVERTISE, UNREGISTER, UNREGISTER_AGENTTYPE, UNREGISTER_INSTANCE, UPDATE, VERIFY, WITHDRAW_CD, XML

Constructor Summary

Constructors

Constructor and Description
KQMLParser() Constructs a new parser that is ready parse new strings.
KQMLParser(String string) Constructs a new parser with the string specified.

Method Summary

Modifier and Type	Method and Description
private String	checkToken(String token, String compare)
KQMLMessage	getKQMLMessage() Parses the previously specified string
protected String	getToken() Retrieves the next token from the internal TokenParser object and throws an exception if none exists.
protected String	getToken(String compare) Retrieves the next token from the internal TokenParser object and throws an exception if none exists.
protected String	getTokenAcceptingParenGroups(String compare)
void	parse() Parses the previously specified string for the purpose of validation as a KQML message.
void	reset(String string) Resets the parser and sets the about-to-be-parsed string to the one specified.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

parser

private TokenParser parser

Constructor Detail

KQMLParser

public KQMLParser()

Constructs a new parser that is ready parse new strings. To set a string to parse use the reset method.

KQMLParser

public KQMLParser(String string)

Constructs a new parser with the string specified. This string will be parsed when the getKQMLmessage method is invoked.

Parameters:

string - string to parse as a KQML message

Method Detail

reset

public void reset(String string)

Resets the parser and sets the about-to-be-parsed string to the one specified.

Parameters:

string - string to parse as a KQML message

getKQMLMessage

public KQMLMessage getKQMLMessage()
                           throws KQMLMessageFormatException

Parses the previously specified string

Returns:

fully parsed KQML message if the string specified could be parsed as a KQML message.

Throws:

MLMessageFormatException - when the string does not appear to be a KQML message and cannot be parsed as such.

KQMLMessageFormatException

parse

public void parse()
           throws KQMLMessageFormatException

Parses the previously specified string for the purpose of validation as a KQML message.

Throws:

MLMessageFormatException - when the string does not appear to be a KQML message and cannot be parsed as such.

KQMLMessageFormatException

getToken

protected String getToken(String compare)
                   throws KQMLMessageFormatException

Retrieves the next token from the internal TokenParser object and throws an exception if none exists. This method is used primarily to fetch perspectives and parameters' value after that parameter has been identified. If the value is null, as in no perspective or no value was found, then the string is considered to be mal-formed.

Parameters:

compare - if not null the token retrieved is compared this value, if it does not match an exception is thrown. This can be used to automatically throw an exception when a string is expected. If null an exception is thrown only if the end of message marker 'CLOSE' is found.

Returns:

the next token (value of the current parameter)

Throws:

MLMessageFormatException - no parameter value was found where there should have been some value. Poorly formatted string?

KQMLMessageFormatException

See Also:

KQML.CLOSE

getTokenAcceptingParenGroups

protected String getTokenAcceptingParenGroups(String compare)
                                       throws KQMLMessageFormatException

Throws:

KQMLMessageFormatException

checkToken

private String checkToken(String token,
                          String compare)
                   throws KQMLMessageFormatException

Throws:

KQMLMessageFormatException

getToken

protected String getToken()
                   throws KQMLMessageFormatException

Retrieves the next token from the internal TokenParser object and throws an exception if none exists. This is used to fetch the next parameter from the target string. If the token is null, as in no parameter was found, then the string is considered to be mal-formed since this method should only be called when other parameters are expected in the string.

Returns:

the next token (value of the current parameter)

Throws:

MLMessageFormatException - no parameter value was found where there should have been some value. Poorly formatted string?

KQMLMessageFormatException