Package org.biojava.bio.program.tagvalue

Class StateMachine

java.lang.Object

org.biojava.bio.program.tagvalue.StateMachine

All Implemented Interfaces:

TagValueListener, TagValueWrapper

public class StateMachine
extends Object
implements TagValueWrapper

This class implements a state machine for parsing events from the Parser class.

Each State can be specified to deliver events to a particular TagValueListener.

Transitions can be specified to occur between States when specific events are encountered. These events can be Tags delivered by startTag as well as the endTag/endRecord events. Events that result in exit from the current State can be specified to be notifiable to the State listener.

In addition, tables of transitions can be defined and specified as the fallback when the a corresponding Transition cannot be found for the tag. This is useful for specifying the destination States that are globally applicable for particular tags. As the fallbacks can be chained, you can end up with a hierarchy of Transition Tables, some being State-specific, others applicable to groups of States and finally one being global.

Author:

David Huen

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
class	StateMachine.BasicState	Implementation of a State in a state machine
static interface	StateMachine.ExitNotification	Interface implemented by State listeners that want notification when a transition leaves the State.
class	StateMachine.SimpleStateListener	a basic listener for a State.
static interface	StateMachine.State	Interface for a State within this StateMachine
class	StateMachine.Transition	class to represent a State Transition
class	StateMachine.TransitionTable	Table of Transition destination States and their corresponding Tags.

Field Summary

Fields

Modifier and Type	Field	Description
protected TagValueListener	delegate
protected static String	END_RECORD_TAG
protected static String	END_TAG
protected static String	MAGICAL_STATE
protected static String	START_RECORD_TAG

Constructor Summary

Constructors

Constructor	Description
StateMachine()

Method Summary

Modifier and Type	Method	Description
StateMachine.BasicState	createState(String label)
StateMachine.TransitionTable	createTransitionTable()
void	endRecord()	The current record has ended.
void	endTag()	End the current tag.
TagValueListener	getDelegate()	get listener to which all calls will be delegated
StateMachine.BasicState	getMagicalState()
StateMachine.State	getState(String label)
void	setDelegate(TagValueListener delegate)	TagValueWrapper interface
void	startRecord()	A new record is about to start.
void	startTag(Object tag)	TagValueListener interface
void	value(TagValueContext ctxt, Object value)	A value has been seen.

Methods inherited from class java.lang.Object

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

Field Detail

START_RECORD_TAG

protected static final String START_RECORD_TAG

See Also:

Constant Field Values

END_RECORD_TAG

protected static final String END_RECORD_TAG

See Also:

Constant Field Values

END_TAG

protected static final String END_TAG

See Also:

Constant Field Values

MAGICAL_STATE

protected static final String MAGICAL_STATE

See Also:

Constant Field Values

delegate

protected TagValueListener delegate

Constructor Detail

StateMachine

public StateMachine()

Method Detail

getMagicalState

public StateMachine.BasicState getMagicalState()

createState

public StateMachine.BasicState createState(String label)

getState

public StateMachine.State getState(String label)

createTransitionTable

public StateMachine.TransitionTable createTransitionTable()

setDelegate

public void setDelegate(TagValueListener delegate)

TagValueWrapper interface

Specified by:

setDelegate in interface TagValueWrapper

getDelegate

public TagValueListener getDelegate()

Description copied from interface: TagValueWrapper

get listener to which all calls will be delegated

Specified by:

getDelegate in interface TagValueWrapper

startTag

public void startTag(Object tag)
              throws ParserException

TagValueListener interface

Specified by:

startTag in interface TagValueListener

Parameters:

tag - the Object representing the new tag

Throws:

ParserException - if the tag could not be started

endTag

public void endTag()
            throws ParserException

Description copied from interface: TagValueListener

End the current tag.

Specified by:

endTag in interface TagValueListener

Throws:

ParserException - if the tag could not be ended

startRecord

public void startRecord()
                 throws ParserException

Description copied from interface: TagValueListener

A new record is about to start.

Specified by:

startRecord in interface TagValueListener

Throws:

ParserException - if the record can not be started

endRecord

public void endRecord()
               throws ParserException

Description copied from interface: TagValueListener

The current record has ended.

Specified by:

endRecord in interface TagValueListener

Throws:

ParserException - if the record can not be ended

value

public void value(TagValueContext ctxt,
                  Object value)
           throws ParserException

Description copied from interface: TagValueListener

A value has been seen.

Specified by:

value in interface TagValueListener

Parameters:

ctxt - a TagValueContext that could be used to push a sub-document

value - the value Object observed

Throws:

ParserException - if the value could not be processed