gumbo.net.msg.ascii
Class AsciiMessageReader

java.lang.Object
  |
  +--gumbo.net.msg.AbstractMessageIO
        |
        +--gumbo.net.msg.ascii.AsciiMessageIO
              |
              +--gumbo.net.msg.ascii.AsciiMessageReader

All Implemented Interfaces:

MessageIO, MessageReader

public class AsciiMessageReader

extends AsciiMessageIO

implements MessageReader

Reads ASCII message elements (units, tokens, delimiters) from a reader.

Note that the StreamTokenizer returns the quote character, not TT_WORD, when a quoted word token is read. This is a crucial point that is sorely missing in the javadoc.

Version:

$Revision: 1.1 $

Author:

Jon Barrilleaux (jonb@jmbaai.com) of JMB and Associates Inc.

Field Summary

Fields inherited from class gumbo.net.msg.ascii.AsciiMessageIO

CHAR_MSG_END, CHAR_UNIT_END, UNIT_BODY, UNIT_DATA, UNIT_DONE, UNIT_FIRST, UNIT_HEAD, UNIT_LAST, UNIT_NONE, UNIT_PARM

Constructor Summary

AsciiMessageReader(java.io.Reader reader)

Method Summary

void	atUnitEnd(int ttype) Used to verify that a special character read in a unit was the unit end.
void	close() Closes this message reader.
double	getTokenNumber() Gets the number in the token last read by readToken().
java.lang.String	getTokenWord() Gets the word in the token last read by readToken().
Message	readMessage() Reads a message, including its end delimiter, in a thread-safe manner.
void	readMessageEnd() Reads the message end delimiter, skipping any white space.
int	readToken() Reads the next token in the current message unit.
java.lang.String	readUnit() Reads the next message unit (head, parameters, or body) and returns its data as a string.
void	readUnitEnd() Reads the message unit end delimiter, skipping any white space.
void	syncMessageEnd() Reads the current message to its end.

Methods inherited from class gumbo.net.msg.ascii.AsciiMessageIO

currentUnit, nextUnit, resetUnit

Methods inherited from class gumbo.net.msg.AbstractMessageIO

addMessageIOListener, fireMessageRead, fireMessageWrite, getMessageIOListeners, removeMessageIOListener

Methods inherited from class java.lang.Object

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

Methods inherited from interface gumbo.net.msg.MessageIO

addMessageIOListener, getMessageIOListeners, removeMessageIOListener

Constructor Detail

AsciiMessageReader

public AsciiMessageReader(java.io.Reader reader)

Method Detail

readToken

public int readToken()
              throws java.io.IOException,
                     MessageIOException

Reads the next token in the current message unit. Blocks until a new token or the unit end is received.

Returns:

StreamTokenizer.TT_EOF if the unit (or message) ended; otherwise, TT_NUMBER or TT_WORD, indicating the type of token read.

Throws:

java.io.IOException - Reader is closed.

MessageIOException - Message ended before unit or message is done.

getTokenWord

public java.lang.String getTokenWord()
                              throws MessageIOException

Gets the word in the token last read by readToken().

Returns:

New String containing the word.

Throws:

MessageIOException - readToken() not yet called or did not read a word.

getTokenNumber

public double getTokenNumber()
                      throws MessageIOException

Gets the number in the token last read by readToken().

Returns:

The number.

Throws:

MessageIOException - readToken() not yet called or did not read a number.

readUnit

public java.lang.String readUnit()
                          throws java.io.IOException,
                                 MessageIOException

Reads the next message unit (head, parameters, or body) and returns its data as a string. Blocks until a new unit is received.

Returns:

A new String containing the unit data (i.e. including whitespace but not the unit delimiter). Empty if no data, but never null.

Throws:

java.io.IOException - Reader is closed.

MessageIOException - Message ended before unit or too many units for message.

readUnitEnd

public void readUnitEnd()
                 throws java.io.IOException,
                        MessageIOException

Reads the message unit end delimiter, skipping any white space. Blocks until the unit end is received.

Throws:

java.io.IOException - Reader is closed.

MessageIOException - Unit is not at the end (i.e. other data found).

atUnitEnd

public void atUnitEnd(int ttype)
               throws java.io.IOException,
                      MessageIOException

Used to verify that a special character read in a unit was the unit end.

Parameters:

ttype - Ttype from a parser.

Throws:

java.io.IOException - Reader is closed.

MessageIOException - Unit is not at the end (i.e. other data found).

readMessageEnd

public void readMessageEnd()
                    throws java.io.IOException,
                           MessageIOException

Reads the message end delimiter, skipping any white space. Blocks until the message end is received.

Throws:

java.io.IOException - Reader is closed.

MessageIOException - Message is not at the end (i.e. other data found) or too few units for message.

close

public void close()
           throws java.io.IOException

Description copied from interface: MessageReader

Closes this message reader.

Specified by:

close in interface MessageReader

java.io.IOException

readMessage

public Message readMessage()
                    throws java.io.IOException,
                           MessageIOException,
                           MessageDataException

Description copied from interface: MessageReader

Reads a message, including its end delimiter, in a thread-safe manner. Blocks until a message is completely received. Typically, this method is synchronized on this message reader, which is used by all threads in the application to receive messages.

Specified by:

readMessage in interface MessageReader

Returns:

The message. Never null.

Throws:

java.io.IOException - Reader is closed.

MessageIOException - Message end not found.

MessageDataException - Message data corrupted.

syncMessageEnd

public void syncMessageEnd()
                    throws java.io.IOException,
                           MessageIOException

Description copied from interface: MessageReader

Reads the current message to its end. Blocks until the end is received. Ignores everything but the message end delimiter. Useful for syncing the message stream following a message exception.

Specified by:

syncMessageEnd in interface MessageReader

Throws:

java.io.IOException - Reader is closed.

MessageIOException - Message end not found (which should never happen).