stella.sensor

Class AbstractSensor

java.lang.Object

util.PropertyContainer

util.PropertyResources

util.rmi.RmiPropertyContainer

util.rmi.AbstractRmiCaster

stella.sensor.AbstractSensor

All Implemented Interfaces:

Cloneable, Remote, RmiErrorCaster, Telemetering, ExitCleaning, Initializable, PropertySupplying, ResourceSupplying, RmiCaster, RmiPropertyBearing

Direct Known Subclasses:

BeckhoffRainSensor, RS485RainImminentSensor, RS485RainSensor, TimerTaskSensor

public abstract class AbstractSensor
extends AbstractRmiCaster
implements Telemetering, RmiErrorCaster, Initializable, ExitCleaning

The abstract base class used for reading abstract sensors. It is implemented as a demon thread, which, once started, keeps reading the sensor values at fixed time intervalls, until the method cancel() is called. The stop() method of Thread is deprecated and should not be used.
To work for different kind of sensors, it is assumed that any sensor has the following properties.

• Every sensor has one measured quantity. This quantity can be represented by a single double.
• Every sensor knows how to read-in this quantity. Normally, this will envolve reading in from a port.
• Every sensor has a unique properties object that can be retrieved from an ascii-file. A required property is a property that must be present in the properties file, otherwise a default value is assigned to the property.

The properties for this class contain at least the following keys (values in parentheses are the default values):

• sensorname (Unnamed): The name of the sensor. Used for binding and equality. Must be unique.
• respawn (1000): The respawning intervall, in ms.
• daemon (true): If true the sensor is a daemon thread, otherwise it gets the default priority.
• bindproperties (false): If true the stella.rmi.RmiPropertyBearing are automatically bound.
• binderror (false): If true the RmiErrorCaster functionality is automatically bound.

As from version 1.0.1, the timing of the readings is taking into account the readout time of the sensor: At start up, the actual time is recorded, and re-reads of the sensor are timed to occur on modulos of the respawn time. Additionally, the time consumed for reading out the sensor is checked and a warning message is issued, if the respawning is too fast. This warning message is issued to any registered RmiErrorListener.

This class and therefore all its subclasses support RMI access. In the basic version a sensor exports its properties to rmi clients via the stella.rmi.RmiPropertyBearing interface and allows rmi error listeners to register via the RmiErrorListener interface. Methods for registering this services to the rmi-registry are provided but must be called seperately. If the appropriate property is set the binding is done at construct.

Version:

1.0.1, 09-10/01/01

Author:

Dr. Thomas Granzer

See Also:

ConvertToPhysical, SmoothingSensor, CumulativeSensor

Nested Class Summary

Nested classes/interfaces inherited from class util.PropertyResources

PropertyResources.Load, PropertyResources.URLResource

Field Summary

Fields

Modifier and Type	Field and Description
private ConvertToPhysical	convert The conversion tool to render physical quantities from raw readings.
private static boolean	DEFBIND The default auto-binding.
private Vector	errlist The list of ErrorListeners.
static String	KEY_BIND The key in the Map referring to auto-binding of the sensor.
static String	KEY_BINDNAME The key in the Map referring to the bind name of the sensor.
static String	KEY_CONVERT The key pointing to the properties file of the conversion object.
static String	KEY_DESCRIPTION The key in the Map list referring to the name of the sensor.
static String	KEY_SENSORNAME The key in the Map list referring to the name of the sensor.

Fields inherited from class util.rmi.AbstractRmiCaster

ALTERNATEHOST, ALTERNATEPORT, KEY_EXPORTPORT, KEY_REGISTRYHOST, KEY_REGISTRYPORT

Fields inherited from class util.PropertyResources

KEY_NOINITONCREATE, POSTFIX_ALPHABET, POSTFIX_BYTES, POSTFIX_DIR, POSTFIX_EXT, POSTFIX_FILE, POSTFIX_LIST, POSTFIX_MODTIME, POSTFIX_URL

Fields inherited from class util.PropertyContainer

KEY_LISTSEPARATOR, KEY_MAPKEYVALUECHAR, KEY_MAPSEPARATOR

Fields inherited from interface util.PropertySupplying

CONFIG, KEY_CLASS

Fields inherited from interface util.ResourceSupplying

KEY_URLRESOURCES, KEY_URLUSECONFIG, KEY_URLUSECURRENT, KEY_URLUSEHOME

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractSensor(Map<String,String> qualify) Constructs a fully-qualified sensor.

Method Summary

Modifier and Type	Method and Description
void	addRmiErrorListener(RmiErrorListener ear) Adds an RmiErrorListener to the registered listeners.
static Telemetering	createSensor(Map<String,String> qualify) Creates a sensor using the class name found in the properties file.
void	exit() Unbind from registry, if bound.
String	getBindName() Returns the name of this sensor used for binding.
ConvertToPhysical	getConvert() Returns the ConvertToPhysical instance used by this data sensor or null if not defined.
long	getRespawn() Returns zero to indicate a threadless sensor.
String	getSensorDescription() Returns a lengthy description of this sensor by parsing through the properties for the KEY_DESCRIPTION entry.
String	getSensorInitInfo() After initialization, we know if we have a conversion object, if we are bound and our name.
String	getSensorName() Returns the name of this sensor.
void	init() Does some initialization immediately after the construction phase.
TimerTask	initSensorTimerTask() Returns null, meaning a thread-less sensor.
protected void	notifyErrorListener(ErrorEvent ee) Notifies all registered ErrorListeners.
void	removeRmiErrorListener(RmiErrorListener ear) Removes an RmiErrorListener from the registered listeners.
void	setConvert(ConvertToPhysical ctp) Sets the ConvertToPhysical instance used by this data sensor.
String	status() A String description of this sensor.
String	toString() A String description of this sensor.

Methods inherited from class util.rmi.AbstractRmiCaster

bindToRegistry, bindToRegistry, bindToRegistry, bindToRegistry, bindToRegistry, bindToRegistry, casterExit, casterExit, getBindName, isValid, unbindFromRegistry, unbindFromRegistry

Methods inherited from class util.rmi.RmiPropertyContainer

containsRemoteProperty, getRemoteProperties, getRemoteProperty, setRemoteProperty

Methods inherited from class util.PropertyResources

clone, createFrom, createFrom, createFrom, createInstance, getApplet, getAsResources, getLocate, getPropertiesToKey, getPropertiesToKey, getResource, getResourceAsStream, getResourceFromKey, getResources, hasLocalURLs, initProperties, keyCreate, keyCreate, reload, setApplet

Methods inherited from class util.PropertyContainer

augment, augment, augment, augment, augment, defaultBoolean, defaultChar, defaultDouble, defaultFloat, defaultInt, defaultLong, defaultObject, defaultObject, defaultProperties, defaultProperty, getAsBoolean, getAsChar, getAsDouble, getAsEnums, getAsFloat, getAsInt, getAsList, getAsLong, getAsMap, getAsMap, getAsObject, getAsObject, getProperties, getProperty, has, isNew, parseObject, parseObject, reload, removeProperty, requires, rescanned, setObject, setProperties, setProperty, stringProperties

Methods inherited from class java.lang.Object

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

Methods inherited from interface stella.sensor.Telemetering

cancel, getReading, getTimeOfRead, validReading

Methods inherited from interface util.PropertySupplying

defaultBoolean, defaultChar, defaultDouble, defaultFloat, defaultInt, defaultLong, defaultObject, defaultObject, defaultProperties, defaultProperty, getAsBoolean, getAsChar, getAsDouble, getAsFloat, getAsInt, getAsList, getAsLong, getAsMap, getAsObject, getAsObject, getProperties, getProperty, has, parseObject, removeProperty, setObject, setProperty, stringProperties

Methods inherited from interface util.rmi.RmiCaster

bindToRegistry, isValid, unbindFromRegistry

Field Detail

KEY_SENSORNAME

public static final String KEY_SENSORNAME

The key in the Map list referring to the name of the sensor.

See Also:

Constant Field Values

KEY_DESCRIPTION

public static final String KEY_DESCRIPTION

The key in the Map list referring to the name of the sensor.

See Also:

Constant Field Values

KEY_BIND

public static final String KEY_BIND

The key in the Map referring to auto-binding of the sensor.

See Also:

Constant Field Values

KEY_BINDNAME

public static final String KEY_BINDNAME

The key in the Map referring to the bind name of the sensor.

See Also:

Constant Field Values

KEY_CONVERT

public static final String KEY_CONVERT

The key pointing to the properties file of the conversion object.

See Also:

Constant Field Values

DEFBIND

private static final boolean DEFBIND

The default auto-binding.

See Also:

Constant Field Values

errlist

private transient Vector errlist

The list of ErrorListeners.

convert

private ConvertToPhysical convert

The conversion tool to render physical quantities from raw readings.

Constructor Detail

AbstractSensor

protected AbstractSensor(Map<String,String> qualify)

Constructs a fully-qualified sensor. The name and the default respawn time is used to construct a default Map object, if the given Map object is null. Use of this constructor guarantees that the Map keys name and respawn are always set.
The Sensor automatically sets its priority to a daemon thread.

Parameters:

group - The ThreadGroup this thread belongs to.

name - The name of this thread (sensor).

qualify - The Map object describing this sensor.

Method Detail

init

public void init()
          throws InitException

Does some initialization immediately after the construction phase. This construct can be used to circumvent timing conflicts during the construction phase. E.g. subclasses can override this method by a simple empty method, comence the construction with the super keyword and add another init routine after the construction phase that eventually calls this method.

Specified by:

init in interface Initializable

Throws:

InitException

exit

public void exit()

Unbind from registry, if bound. Signal error listeners that they should fuck off.

Specified by:

exit in interface ExitCleaning

Overrides:

exit in class AbstractRmiCaster

getConvert

public ConvertToPhysical getConvert()

Returns the ConvertToPhysical instance used by this data sensor or null if not defined.

Specified by:

getConvert in interface Telemetering

setConvert

public void setConvert(ConvertToPhysical ctp)

Sets the ConvertToPhysical instance used by this data sensor.

Specified by:

setConvert in interface Telemetering

initSensorTimerTask

public TimerTask initSensorTimerTask()

Returns null, meaning a thread-less sensor. Sensors that actually need a thread must override this method.

Specified by:

initSensorTimerTask in interface Telemetering

Returns:

The ready-to-start timer-task of this sensor.

See Also:

Telemetering.getRespawn()

getRespawn

public long getRespawn()

Returns zero to indicate a threadless sensor. Sensors that actually need a thread must override this method.

Specified by:

getRespawn in interface Telemetering

Returns:

Zero, if this sensor does not need a thread.

createSensor

public static Telemetering createSensor(Map<String,String> qualify)

Creates a sensor using the class name found in the properties file. If the class construction fails for any reason a error message is printed to system err and the thrown exception is propagated up. Note that direct notification of RmiErrorListeners is not possible prior to sensor construction.

Parameters:

qualify - The properties of the new sensor.

getSensorName

public String getSensorName()

Returns the name of this sensor. Using one of the non-trivial constructors gurantees that the name property is set.
Note that the name should be unique.

Specified by:

getSensorName in interface Telemetering

Returns:

A qualifying name.

getBindName

public String getBindName()

Returns the name of this sensor used for binding. Note that this name is per definition unique.

Overrides:

getBindName in class AbstractRmiCaster

Returns:

A qualifying name.

getSensorDescription

public String getSensorDescription()

Returns a lengthy description of this sensor by parsing through the properties for the KEY_DESCRIPTION entry. If this property is not set, we return the sensor name.

Specified by:

getSensorDescription in interface Telemetering

getSensorInitInfo

public String getSensorInitInfo()

After initialization, we know if we have a conversion object, if we are bound and our name. This info is returned in a comprehensive way.

Specified by:

getSensorInitInfo in interface Telemetering

addRmiErrorListener

public void addRmiErrorListener(RmiErrorListener ear)
                         throws RemoteException

Adds an RmiErrorListener to the registered listeners. If the argument is null, nothing is changed.

Specified by:

addRmiErrorListener in interface RmiErrorCaster

Parameters:

ear - The listener to add.

Throws:

RemoteException

Since:

1.0.1

removeRmiErrorListener

public void removeRmiErrorListener(RmiErrorListener ear)
                            throws RemoteException

Removes an RmiErrorListener from the registered listeners. If the argument is null, nothing is changed.

Specified by:

removeRmiErrorListener in interface RmiErrorCaster

Parameters:

ear - The listener to remove.

Throws:

RemoteException

Since:

1.0.1

toString

public String toString()

A String description of this sensor. Returns the name of the sensor.

Overrides:

toString in class PropertyContainer

status

public String status()

A String description of this sensor. Returns the name and readiung of the sensor.

Specified by:

status in interface Telemetering

notifyErrorListener

protected void notifyErrorListener(ErrorEvent ee)

Notifies all registered ErrorListeners. This method parses through the Vector of ErrorListeners and passes the argument to their errorOccured method. Per default the SystemErrListener is registered, which simply outputs the error message to System.err.

Parameters:

ee - The ErrorEvent to pass to the Listeners.

Since:

1.0.1