ptolemy.actor.lib
Class URLReader

java.lang.Object
  ptolemy.kernel.util.NamedObj
      ptolemy.kernel.InstantiableNamedObj
          ptolemy.kernel.Entity
              ptolemy.kernel.ComponentEntity
                  ptolemy.actor.AtomicActor
                      ptolemy.actor.TypedAtomicActor
                          ptolemy.actor.lib.Source
                              ptolemy.actor.lib.URLReader

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, Actor, Executable, FiringsRecordable, Initializable, TypedActor, Changeable, Debuggable, DebugListener, Derivable, Instantiable, ModelErrorHandler, MoMLExportable, Moveable, Nameable

Direct Known Subclasses:

DoubleReader, DoubleReader, URLDirectoryReader

public abstract class URLReader
extends Source

This actor reads tokens from an URL, and output them. Each entry in the file corresponds to one iteration. If there are multiple fires in the iteration, the same token will be repeated. This actor has a multiport, where each port corresponds to one column in the data file.

The file format at the URL is assumed as the following. A newline character separates the rows, and a tab or a space character separates the columns.

The sourceURL parameter should be set to the name of the file, specified as a fully qualified URL. If the sourceURL parameter is an empty string, then the System.in is used for input. It is possible to load a file from the local file system by using the prefix "file://" instead of "http://". Relative file paths are allowed. To specify a file relative to the current directory, use "../" or "./". For example, if the current directory contains a file called "test.txt", then sourceURL should be set to "file:./test.txt". If the parent directory contains a file called "test.txt", then sourceURL should be set to "file:../test.txt". To reference the file test.txt, located at "/tmp/test.txt", sourceURL should be set to "file:///tmp/test.txt" The default value is "file:///tmp/test.txt".

FIXME: The type of the output ports is set to Double for now. It should read a line in the prefire() and refer the type from there.

FIXME: URLReader should read in expressions and serialized tokens

Since:

Ptolemy II 2.0

Version:

$Id: URLReader.java 57040 2010-01-27 20:52:32Z cxh $

Author:

Jie Liu

See Also:

AudioReader, Serialized Form

Accepted Rating:

Red (liuj)

Proposed Rating:

Red (liuj)

Nested Class Summary

Nested classes/interfaces inherited from class ptolemy.kernel.Entity

Entity.ContainedObjectsIterator

Field Summary

protected java.io.BufferedReader	_reader The reader to read from.
protected boolean	_refreshFlag Flag to indicate whether or not to refresh the data between readings.
protected java.lang.String	_source String for the URL.
protected static java.io.BufferedReader	_stdIn Standard in as a reader.
Parameter	refresh The flag that indicates whether to refresh between each reading.
Parameter	sourceURL The URL of the file to read from.

Fields inherited from class ptolemy.actor.lib.Source

output, trigger

Fields inherited from class ptolemy.actor.AtomicActor

_actorFiringListeners, _initializables, _notifyingActorFiring, _stopRequested

Fields inherited from class ptolemy.kernel.util.NamedObj

_changeListeners, _changeLock, _changeRequests, _debugging, _debugListeners, _elementName, _isPersistent, _verbose, _workspace, ATTRIBUTES, CLASSNAME, COMPLETE, CONTENTS, DEEP, FULLNAME, LINKS

Fields inherited from interface ptolemy.actor.Executable

COMPLETED, NOT_READY, STOP_ITERATING

Constructor Summary

URLReader(CompositeEntity container, java.lang.String name)
Construct an actor with the given container and name.

Method Summary

protected void	_setURLReader(java.io.BufferedReader reader) Set the reader.
void	attributeChanged(Attribute attribute) If the specified attribute is URL, then close the current file (if there is one) and open the new one.
void	initialize() Open the file at the URL, and set the width of the output.
void	wrapup() Close the reader if there is one.

Methods inherited from class ptolemy.actor.lib.Source

fire, prefire

Methods inherited from class ptolemy.actor.TypedAtomicActor

_addPort, _fireAt, _fireAt, attributeTypeChanged, clone, newPort, typeConstraintList, typeConstraints

Methods inherited from class ptolemy.actor.AtomicActor

_actorFiring, _actorFiring, addActorFiringListener, addInitializable, clone, connectionsChanged, createReceivers, declareDelayDependency, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, isFireFunctional, isStrict, iterate, newReceiver, outputPortList, postfire, preinitialize, pruneDependencies, recordFiring, removeActorFiringListener, removeDependency, removeInitializable, setContainer, stop, stopFire, terminate

Methods inherited from class ptolemy.kernel.ComponentEntity

_adjustDeferrals, _checkContainer, _getContainedObject, _propagateExistence, getContainer, instantiate, isAtomic, isOpaque, moveDown, moveToFirst, moveToIndex, moveToLast, moveUp, propagateExistence, setName

Methods inherited from class ptolemy.kernel.Entity

_description, _exportMoMLContents, _removePort, _validateSettables, connectedPortList, connectedPorts, containedObjectsIterator, getAttribute, getPort, getPorts, linkedRelationList, linkedRelations, portList, removeAllPorts, setClassDefinition, uniqueName

Methods inherited from class ptolemy.kernel.InstantiableNamedObj

_setParent, exportMoML, getChildren, getElementName, getParent, getPrototypeList, isClassDefinition, isWithinClassDefinition

Methods inherited from class ptolemy.kernel.util.NamedObj

_addAttribute, _adjustOverride, _attachText, _cloneFixAttributeFields, _debug, _debug, _debug, _debug, _debug, _getIndentPrefix, _isMoMLSuppressed, _markContentsDerived, _propagateValue, _recordDecoratedAttributes, _removeAttribute, _splitName, _stripNumericSuffix, addChangeListener, addDebugListener, attributeList, attributeList, deepContains, depthInHierarchy, description, description, event, executeChangeRequests, exportMoML, exportMoML, exportMoML, exportMoML, exportMoMLPlain, getAttribute, getAttributes, getChangeListeners, getClassName, getDecoratorAttribute, getDecoratorAttributes, getDerivedLevel, getDerivedList, getDisplayName, getFullName, getModelErrorHandler, getName, getName, getSource, handleModelError, isDeferringChangeRequests, isOverridden, isPersistent, lazyContainedObjectsIterator, message, propagateValue, propagateValues, removeChangeListener, removeDebugListener, requestChange, setClassName, setDeferringChangeRequests, setDerivedLevel, setDisplayName, setModelErrorHandler, setPersistent, setSource, sortContainedObjects, toplevel, toString, validateSettables, workspace

Methods inherited from class java.lang.Object

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

Methods inherited from interface ptolemy.actor.Actor

createReceivers, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, newReceiver, outputPortList

Methods inherited from interface ptolemy.actor.Executable

isFireFunctional, isStrict, iterate, postfire, stop, stopFire, terminate

Methods inherited from interface ptolemy.actor.Initializable

addInitializable, preinitialize, removeInitializable

Methods inherited from interface ptolemy.kernel.util.Nameable

description, getContainer, getDisplayName, getFullName, getName, getName, setName

Methods inherited from interface ptolemy.kernel.util.Derivable

getDerivedLevel, getDerivedList, propagateValue

Field Detail

sourceURL

public Parameter sourceURL

The URL of the file to read from. This parameter contains a StringToken. By default, it contains an empty string, which is interpreted to mean that input should be directed to the standard input. FIXME: Should this bring up a dialog box to type (or select) a URL?

refresh

public Parameter refresh

The flag that indicates whether to refresh between each reading. This is a boolean, and defaults to false.

_reader

protected java.io.BufferedReader _reader

The reader to read from.

_stdIn

protected static java.io.BufferedReader _stdIn

Standard in as a reader.

_source

protected java.lang.String _source

String for the URL.

_refreshFlag

protected boolean _refreshFlag

Flag to indicate whether or not to refresh the data between readings.

Constructor Detail

URLReader

public URLReader(CompositeEntity container,
                 java.lang.String name)
          throws IllegalActionException,
                 NameDuplicationException

Construct an actor with the given container and name.

Parameters:

container - The container.

name - The name of this actor.

Throws:

IllegalActionException - If the actor cannot be contained by the proposed container.

NameDuplicationException - If the container already has an actor with this name.

Method Detail

attributeChanged

public void attributeChanged(Attribute attribute)
                      throws IllegalActionException

If the specified attribute is URL, then close the current file (if there is one) and open the new one.

Overrides:

attributeChanged in class NamedObj

Parameters:

attribute - The attribute that has changed.

Throws:

IllegalActionException - If the specified attribute is URL and the file cannot be opened.

initialize

public void initialize()
                throws IllegalActionException

Open the file at the URL, and set the width of the output.

Specified by:

initialize in interface Initializable

Overrides:

initialize in class AtomicActor

Throws:

IllegalActionException - Not thrown in this base class

wrapup

public void wrapup()
            throws IllegalActionException

Close the reader if there is one.

Specified by:

wrapup in interface Initializable

Overrides:

wrapup in class AtomicActor

Throws:

IllegalActionException - If an IO error occurs.

_setURLReader

protected void _setURLReader(java.io.BufferedReader reader)
                      throws IllegalActionException

Set the reader. If there was a previous reader, close it. To set standard input, call this method with argument null.

Parameters:

reader - The reader to read to.

Throws:

IllegalActionException - If an IO error occurs.