stella.globals

Class SnapshotParameter

java.lang.Object

util.PropertyContainer

util.PropertyResources

globals.parameter.AbstractParameter

stella.globals.SnapshotParameter

All Implemented Interfaces:

Parameter, ParameterDepending, Cloneable, ErrorDependingParameter, ExitCleaning, Initializable, PropertySupplying, Reloadable, ResourceSupplying

Direct Known Subclasses:

SnapshotValue

public class SnapshotParameter
extends AbstractParameter
implements ParameterDepending, ErrorDependingParameter, Reloadable

A snapshot parameter records the value of an other parameter at a certain time. As unpredicted points-in-time are asociated with errors, this value-fixation should be triggered by an error received in the main stella.GlobalGrouping instance.

Nested Class Summary

Nested classes/interfaces inherited from class util.PropertyResources

PropertyResources.Load, PropertyResources.URLResource

Field Summary

Fields

Modifier and Type	Field and Description
static String	KEY_ERROR The class name of the error that serves as a snapshot-trigger.
static String	KEY_PARAMETER The name of the parameter which value should be recorded on error.
private Object	record The value of the asociated parameter at time of snapshot.
private Parameter	snapshot The asociated parameter.

Fields inherited from class globals.parameter.AbstractParameter

KEY_FORMAT, KEY_NAME, KEY_PRESERVE, UNKNOWN

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 stella.ErrorDependingParameter

NAMING_EXTENSION

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

Constructor and Description
SnapshotParameter(Map<String,String> prop) Constructs a new snapshot parameter.

Method Summary

Modifier and Type	Method and Description
Object	get() Gets the last snapshot value.
Object	getForError(ErrorEvent err) Checks if the error received is of the type specified in the KEY_ERROR property.
private boolean	myError(ErrorEvent err) Returns true if we act on this error.
void	registerError(ErrorEvent err) Registers the error.
void	registerParameter(Parameter watch) Registers the asociated parameter which value should be recorded.
double	rescanned(String key, String old, String newval) As any parameter depending instance we fail if the parameter we depend on is now a different one.
Object	set(Object newval) Sets the snapshot value.

Methods inherited from class globals.parameter.AbstractParameter

createParameter, delivers, exit, getFormatted, getFormatted, getName, getPreserveFile, getString, getString, init, overrideDefaultName, register, setName, toString

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, setObject, setProperties, setProperty, stringProperties

Methods inherited from class java.lang.Object

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

Methods inherited from interface globals.Parameter

getFormatted, getName, getString

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.Initializable

init

Methods inherited from interface util.Reloadable

reload

Field Detail

KEY_PARAMETER

public static final String KEY_PARAMETER

The name of the parameter which value should be recorded on error.

See Also:

Constant Field Values

KEY_ERROR

public static final String KEY_ERROR

The class name of the error that serves as a snapshot-trigger.

See Also:

Constant Field Values

snapshot

private Parameter snapshot

The asociated parameter.

record

private Object record

The value of the asociated parameter at time of snapshot.

Constructor Detail

SnapshotParameter

public SnapshotParameter(Map<String,String> prop)

Constructs a new snapshot parameter.

Method Detail

rescanned

public double rescanned(String key,
                        String old,
                        String newval)

As any parameter depending instance we fail if the parameter we depend on is now a different one.

Specified by:

rescanned in interface Reloadable

Overrides:

rescanned in class AbstractParameter

registerParameter

public void registerParameter(Parameter watch)

Registers the asociated parameter which value should be recorded. Checks the name of the parameter handed over against KEY_PARAMETER

Specified by:

registerParameter in interface ParameterDepending

getForError

public Object getForError(ErrorEvent err)

Checks if the error received is of the type specified in the KEY_ERROR property. If so, the current value of the observed parameter is returned, otherwise null is returned.

Specified by:

getForError in interface ErrorDependingParameter

registerError

public void registerError(ErrorEvent err)

Registers the error. If the error is recognized, i.e. the #getFor method return a non-null value, the value of this parameter is adjusted to reflect the value of the served parameter at the time this error was registered.

Specified by:

registerError in interface ErrorDependingParameter

myError

private boolean myError(ErrorEvent err)

Returns true if we act on this error.

get

public Object get()

Gets the last snapshot value. If a no error specified in KEY_ERROR was received since the watched parameter registration, null is returned.

Specified by:

get in interface Parameter

set

public Object set(Object newval)

Sets the snapshot value. Not allowed.

Specified by:

set in interface Parameter

Returns:

The previous value of this parameter.