stella.xml

Class SequenceErrorFinalizer

java.lang.Object

util.PropertyContainer

util.PropertyResources

stella.AbstractErrorFinalizer

stella.xml.SequenceErrorFinalizer

All Implemented Interfaces:

Cloneable, ErrorFinalizing, Initializable, PropertySupplying, ResourceSupplying

public class SequenceErrorFinalizer
extends AbstractErrorFinalizer
implements ErrorFinalizing

A simple error finalizer acting directly on the XMLSequencer. It is used to handle a single KEY_FOLLOWUP by loading an alternate sequence with ResourceSupplying.KEY_URLRESOURCES and KEY_XMLFILE. Depending on KEY_TYPE, this new sequence is inserted into the running sequence in one of three ways.

• ABORT: The normal sequence is aborted and replaced with the new one. This error-handling method is normally used for severe errors where recovery is not possible.
• APPEND: The sequence derived from the error-recovery steps is appended to the current sequence. This means that error handling is delayed until the last command in the normal sequence has been completed. This error handling is more a clean-up procedure.
• PREPEND: he sequence derived from the error-recovery steps is prpended to the current sequence. This means that error handling occurs as the next set of commands. This error handling is ment for errors that may be solved with retries.

A simple error handler can only handle errors that change the currently executing sequence by either prepending or appending some additional sequencer steps or by aborting the entire sequence. If your error casters produce errors that can not be treated with this simple schema a new ErrorFinalizing instance has to be coded.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private class	SequenceErrorFinalizer.ErrorDistributor Helper class to speed up the return from the error listener method ErrorListener.errorOccured(stella.ErrorEvent).

Nested classes/interfaces inherited from class util.PropertyResources

PropertyResources.Load, PropertyResources.URLResource

Field Summary

Fields

Modifier and Type	Field and Description
static String	ABORT A constant indicating replacement of the non-error sequence.
private SequenceErrorFinalizer.ErrorDistributor	alternate The thread handling the sequence update.
static String	APPEND A constant defining appending of the error-handling sequnce.
private static String	DEFFOLLOWUP The default follow-up.
private static String	DEFTYPE The default behaviour.
private static String	DEFXMLFILE A file holding the shutdown sequence.
static String	KEY_FOLLOWUP The follow-up action.
static String	KEY_TYPE The way of insertion into the running sequence.
static String	KEY_XMLFILE The sequence file to load.
static String	PREPEND A constant defining prepending of the error-handling sequnce.

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

Constructor and Description
SequenceErrorFinalizer(Map<String,String> prop) Constructs a new simple error handler.

Method Summary

Modifier and Type	Method and Description
boolean	finalizeError(TargetDefinition ignore, ErrorEvent ee, CommandLaunching[] dummy, Sequencing seq, ParameterClustering set) The incomming errors.
String	getFollowUp() Gets the follow-up this error finalizer works on.
boolean	isAborting() Returns true if this error finalizer is acting on a ErrorEvent.ABORT_TARGET follow-up and is currently finalizing.
boolean	isFinalizing() Returns if this error finalizer is still working on the last error.
protected boolean	startRecovery(URL xml, String type, Sequencing<SequenceStep> seq) Starts the sequence-updating thread.

Methods inherited from class stella.AbstractErrorFinalizer

createErrorFinalizer, init, setMonitor, wake

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, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface stella.ErrorFinalizing

setMonitor

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

Field Detail

KEY_XMLFILE

public static final String KEY_XMLFILE

The sequence file to load.

See Also:

Constant Field Values

KEY_TYPE

public static final String KEY_TYPE

The way of insertion into the running sequence.

See Also:

Constant Field Values

KEY_FOLLOWUP

public static final String KEY_FOLLOWUP

The follow-up action.

See Also:

Constant Field Values

ABORT

public static final String ABORT

A constant indicating replacement of the non-error sequence.

See Also:

Constant Field Values

APPEND

public static final String APPEND

A constant defining appending of the error-handling sequnce.

See Also:

Constant Field Values

PREPEND

public static final String PREPEND

A constant defining prepending of the error-handling sequnce.

See Also:

Constant Field Values

DEFXMLFILE

private static final String DEFXMLFILE

A file holding the shutdown sequence. Last resort of error handling.

See Also:

Constant Field Values

DEFFOLLOWUP

private static final String DEFFOLLOWUP

The default follow-up. Initiates a shutdowen.

See Also:

Constant Field Values

DEFTYPE

private static final String DEFTYPE

The default behaviour. Current sequence is aborted.

See Also:

Constant Field Values

alternate

private SequenceErrorFinalizer.ErrorDistributor alternate

The thread handling the sequence update.

Constructor Detail

SequenceErrorFinalizer

public SequenceErrorFinalizer(Map<String,String> prop)

Constructs a new simple error handler. Registering the command servers, the sequencer, and the scheduler are done in the parent class.

Method Detail

finalizeError

public boolean finalizeError(TargetDefinition ignore,
                             ErrorEvent ee,
                             CommandLaunching[] dummy,
                             Sequencing seq,
                             ParameterClustering set)

The incomming errors. First, the error message is querried for its single follow-up action. If the follow-up is handled by this finalizer, its alternate sequnece is loaded and than passed to the appropriate sequencer method, i.e., Sequencing.abort(java.util.List<E>), Sequencing.append(java.util.List<E>) , or Sequencing.prepend(java.util.List<E>). To ensure quick return of this method, a seperate thread is started, see SequenceErrorFinalizer.ErrorDistributor.

Specified by:

finalizeError in interface ErrorFinalizing

startRecovery

protected boolean startRecovery(URL xml,
                                String type,
                                Sequencing<SequenceStep> seq)

Starts the sequence-updating thread. This thread is also needed for the isFinalizing() method.

getFollowUp

public String getFollowUp()

Gets the follow-up this error finalizer works on. Different errors may be handled with identical instances of this class.

Specified by:

getFollowUp in interface ErrorFinalizing

isFinalizing

public boolean isFinalizing()

Returns if this error finalizer is still working on the last error. Checks if the SequenceErrorFinalizer.ErrorDistributor is non-null and alive.

Specified by:

isFinalizing in interface ErrorFinalizing

isAborting

public boolean isAborting()

Returns true if this error finalizer is acting on a ErrorEvent.ABORT_TARGET follow-up and is currently finalizing.

Specified by:

isAborting in interface ErrorFinalizing

Overrides:

isAborting in class AbstractErrorFinalizer