com.rabbitmq.jms.parse.sql

Class SqlTokenStream

java.lang.Object

com.rabbitmq.jms.parse.sql.SqlTokenStream

All Implemented Interfaces:

TokenStream<com.rabbitmq.jms.parse.sql.SqlToken,java.lang.Integer>

public class SqlTokenStream
extends java.lang.Object
implements TokenStream<com.rabbitmq.jms.parse.sql.SqlToken,java.lang.Integer>

A simple stream of SQL tokens generated from an input character sequence at instantiation time.

Apart from the TokenStream operations this implementation also supports a getResidue() method, which returns the character sequence remaining after lexical scanning. If this is not empty, the tokeniser failed to completely scan the input.

Constructor Summary

Constructors

Constructor and Description
SqlTokenStream(java.lang.CharSequence cseq) The constructor builds the whole token stream from the given character sequence by tokenising it.

Method Summary

Modifier and Type	Method and Description
com.rabbitmq.jms.parse.sql.SqlToken	getNext() Increment position in the stream; no-op if already at the end.
java.lang.CharSequence	getResidue() After this object is instantiated there may be characters in the initial sequence which were not able to be tokenized.
boolean	moreTokens()
java.lang.Integer	position()
com.rabbitmq.jms.parse.sql.SqlToken	readToken() Reads token at the current position and the position is not changed.
void	reset() Reset the stream to the start.
void	reset(java.lang.Integer position) Reset the stream to the position provided, if it is a valid position.
void	stepBack() Decrement position in the stream; no-op if already at the beginning.

Methods inherited from class java.lang.Object

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

Constructor Detail

SqlTokenStream

public SqlTokenStream(java.lang.CharSequence cseq)

The constructor builds the whole token stream from the given character sequence by tokenising it. The tokens are defined by the SqlTokenType enum type.

This never fails with an exception, but may not consume many (or any) characters from cseq and return most of the original sequence in getResidue().

Parameters:

cseq - - the sequence of characters (for example a String) which is tokenized

See Also:

SqlTokenType, tokenize(CharSequence)

Method Detail

getResidue

public java.lang.CharSequence getResidue()

After this object is instantiated there may be characters in the initial sequence which were not able to be tokenized. The characters after which the tokenizer could not determine any more tokens are returned by this method.

Returns:

the characters after the first non-tokenisable chars in the intial sequence.

moreTokens

public boolean moreTokens()

Specified by:

moreTokens in interface TokenStream<com.rabbitmq.jms.parse.sql.SqlToken,java.lang.Integer>

Returns:

true if there are more tokens after the current position in the stream

readToken

public com.rabbitmq.jms.parse.sql.SqlToken readToken()

Description copied from interface: TokenStream

Reads token at the current position and the position is not changed.

Specified by:

readToken in interface TokenStream<com.rabbitmq.jms.parse.sql.SqlToken,java.lang.Integer>

Returns:

the current Token in the stream if any, otherwise null

getNext

public com.rabbitmq.jms.parse.sql.SqlToken getNext()

Description copied from interface: TokenStream

Increment position in the stream; no-op if already at the end.

Specified by:

getNext in interface TokenStream<com.rabbitmq.jms.parse.sql.SqlToken,java.lang.Integer>

Returns:

the next Token in the stream if any, otherwise null

position

public java.lang.Integer position()

Specified by:

position in interface TokenStream<com.rabbitmq.jms.parse.sql.SqlToken,java.lang.Integer>

Returns:

the current position in the stream

stepBack

public void stepBack()

Description copied from interface: TokenStream

Decrement position in the stream; no-op if already at the beginning.

Specified by:

stepBack in interface TokenStream<com.rabbitmq.jms.parse.sql.SqlToken,java.lang.Integer>

reset

public void reset(java.lang.Integer position)

Description copied from interface: TokenStream

Reset the stream to the position provided, if it is a valid position. Otherwise undefined.

Specified by:

reset in interface TokenStream<com.rabbitmq.jms.parse.sql.SqlToken,java.lang.Integer>

Parameters:

position - - previously returned place in the stream

reset

public void reset()

Description copied from interface: TokenStream

Reset the stream to the start. Equivalent to tokenStream.reset(START) where Position START = tokenStream.getPosition(); was executed first after instantiation of the TokenStream.

Specified by:

reset in interface TokenStream<com.rabbitmq.jms.parse.sql.SqlToken,java.lang.Integer>