public class LineReader extends Source
This actor reads a file or URL, one line at a time, and outputs each line as a string. The file or URL is specified using any form acceptable to FileParameter. Before an end of file is reached, the endOfFile output produces false. In the iteration where the last line of the file is read and produced on the output port, this actor produces true on the endOfFile port. In that iteration, postfire() returns false. If the actor is iterated again, after the end of file, then prefire() and postfire() will both return false, output will produce the string "EOF", and endOfFile will produce true.
In some domains (such as SDF), returning false in postfire() causes the model to cease executing. In other domains (such as DE), this causes the director to avoid further firings of this actor. So usually, the actor will not be invoked again after the end of file is reached.
This actor reads ahead in the file so that it can produce an output true on endOfFile in the same iteration where it outputs the last line.
This actor can skip some lines at the beginning of the file or URL, with the number specified by the numberOfLinesToSkip parameter. The default value of this parameter is 0.
If you need to reset this line reader to start again at the beginning of the file, the way to do this is to call initialize() during the run of the model. This can be done, for example, using a modal model with a transition where reset is enabled.
FileParameter| Yellow (cxh) |
| Green (eal) |
Entity.ContainedObjectsIterator| Modifier and Type | Field and Description |
|---|---|
protected java.lang.String |
_currentLine
Cache of most recently read data.
|
protected boolean |
_firstFiring
First firing indicator.
|
protected java.lang.String |
_nextLine
The next line after the current line.
|
protected java.io.BufferedReader |
_reader
The current reader for the input file.
|
TypedIOPort |
endOfFile
An output port that produces false until the end of file
is reached, at which point it produces true.
|
FilePortParameter |
fileOrURL
The file name or URL from which to read.
|
Parameter |
numberOfLinesToSkip
The number of lines to skip at the beginning of the file or URL.
|
_triggered, output, trigger_typesValid_actorFiringListeners, _initializables, _notifyingActorFiring, _stopRequested_changeListeners, _changeLock, _changeRequests, _debugging, _debugListeners, _deferChangeRequests, _elementName, _isPersistent, _verbose, _workspace, ATTRIBUTES, CLASSNAME, COMPLETE, CONTENTS, DEEP, FULLNAME, LINKSCOMPLETED, NOT_READY, STOP_ITERATING| Constructor and Description |
|---|
LineReader(CompositeEntity container,
java.lang.String name)
Construct an actor with the given container and name.
|
| Modifier and Type | Method and Description |
|---|---|
protected void |
_openAndReadFirstTwoLines()
Open the file and read the first line, putting its value into
the _currentLine variable.
|
void |
attributeChanged(Attribute attribute)
If the specified attribute is fileOrURL and there is an
open file being read, then close that file and open the new one;
if the attribute is numberOfLinesToSkip and its value is
negative, then throw an exception.
|
java.lang.Object |
clone(Workspace workspace)
Clone the actor into the specified workspace.
|
void |
fire()
Output the data read in the preinitialize() or in the previous
invocation of postfire(), if there is any.
|
void |
initialize()
If this is called after prefire() has been called but before
wrapup() has been called, then close any
open file re-open it, skip the number of lines given by the
numberOfLinesToSkip parameter, and read the first line to
be produced in the next invocation of prefire().
|
boolean |
postfire()
Read the next line from the file.
|
void |
wrapup()
Close the reader if there is one.
|
_customTypeConstraints, prefire_containedTypeConstraints, _defaultTypeConstraints, _fireAt, _fireAt, attributeTypeChanged, clone, isBackwardTypeInferenceEnabled, newPort, typeConstraintList, typeConstraints_actorFiring, _actorFiring, _declareDelayDependency, addActorFiringListener, addInitializable, connectionsChanged, createReceivers, declareDelayDependency, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, isFireFunctional, isStrict, iterate, newReceiver, outputPortList, preinitialize, pruneDependencies, recordFiring, removeActorFiringListener, removeDependency, removeInitializable, setContainer, stop, stopFire, terminate_adjustDeferrals, _checkContainer, _getContainedObject, _propagateExistence, getContainer, instantiate, isAtomic, isOpaque, moveDown, moveToFirst, moveToIndex, moveToLast, moveUp, propagateExistence, setName_addPort, _description, _exportMoMLContents, _removePort, _validateSettables, connectedPortList, connectedPorts, containedObjectsIterator, getAttribute, getPort, getPorts, linkedRelationList, linkedRelations, portList, removeAllPorts, setClassDefinition, uniqueName_setParent, exportMoML, getChildren, getElementName, getParent, getPrototypeList, isClassDefinition, isWithinClassDefinition_addAttribute, _adjustOverride, _attachText, _cloneFixAttributeFields, _containedDecorators, _copyChangeRequestList, _debug, _debug, _debug, _debug, _debug, _executeChangeRequests, _getIndentPrefix, _isMoMLSuppressed, _markContentsDerived, _notifyHierarchyListenersAfterChange, _notifyHierarchyListenersBeforeChange, _propagateValue, _removeAttribute, _splitName, _stripNumericSuffix, addChangeListener, addDebugListener, addHierarchyListener, attributeDeleted, attributeList, attributeList, decorators, 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, notifyOfNameChange, propagateValue, propagateValues, removeAttribute, removeChangeListener, removeDebugListener, removeHierarchyListener, requestChange, setClassName, setDeferringChangeRequests, setDerivedLevel, setDisplayName, setModelErrorHandler, setPersistent, setSource, sortContainedObjects, toplevel, toString, validateSettables, workspaceequals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, waitcreateReceivers, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, newReceiver, outputPortListisFireFunctional, isStrict, iterate, stop, stopFire, terminateaddInitializable, preinitialize, removeInitializabledescription, getContainer, getDisplayName, getFullName, getName, getName, setNamegetDerivedLevel, getDerivedList, propagateValuepublic TypedIOPort endOfFile
public FilePortParameter fileOrURL
FileParameterpublic Parameter numberOfLinesToSkip
protected java.lang.String _currentLine
protected java.lang.String _nextLine
protected java.io.BufferedReader _reader
protected boolean _firstFiring
public LineReader(CompositeEntity container, java.lang.String name) throws IllegalActionException, NameDuplicationException
container - The container.name - The name of this actor.IllegalActionException - If the actor cannot be contained
by the proposed container.NameDuplicationException - If the container already has an
actor with this name.public void attributeChanged(Attribute attribute) throws IllegalActionException
attributeChanged in class NamedObjattribute - The attribute that has changed.IllegalActionException - If the specified attribute
is fileOrURL and the file cannot be opened, or the previously
opened file cannot be closed; or if the attribute is
numberOfLinesToSkip and its value is negative.public java.lang.Object clone(Workspace workspace) throws java.lang.CloneNotSupportedException
clone in class TypedAtomicActorworkspace - The workspace for the new object.java.lang.CloneNotSupportedException - If a derived class contains
an attribute that cannot be cloned.NamedObj.exportMoML(Writer, int, String),
NamedObj.setDeferringChangeRequests(boolean)public void fire()
throws IllegalActionException
fire in interface Executablefire in class SourceIllegalActionException - If there's no director.public void initialize()
throws IllegalActionException
initialize in interface Initializableinitialize in class AtomicActor<TypedIOPort>IllegalActionException - If the file or URL cannot be
opened, or if the lines to be skipped and the first line to be
sent out in the fire() method cannot be read.public boolean postfire()
throws IllegalActionException
postfire in interface Executablepostfire in class AtomicActor<TypedIOPort>IllegalActionException - If there is a problem reading
the file.public void wrapup()
throws IllegalActionException
wrapup in interface Initializablewrapup in class AtomicActor<TypedIOPort>IllegalActionException - If an IO error occurs.protected void _openAndReadFirstTwoLines()
throws IllegalActionException
IllegalActionException - If the file cannot be read.