de.aristaflow.adept2.core.runtimemanager.executionenvironments

Class IDExecutionEnvironment

java.lang.Object

de.aristaflow.adept2.core.runtimemanager.executionenvironments.ExecutionEnvironment

de.aristaflow.adept2.core.runtimemanager.executionenvironments.IDExecutionEnvironment

All Implemented Interfaces:

ExecutableComponent

public class IDExecutionEnvironment
extends ExecutionEnvironment

The ID Execution Environment is used for executing application which though they implement the ExecutableComponent interface don't have an ADEPT2-Registry conform constructor.
The activity URI is used for retrieving the class to be executed by this environment. This class is instantiated via an empty Constructor which must exist and be public. The component runs inside the same thread as this execution environment so that no additional synchronisation is required and it is ensured that the component is always called by the same thread. Most of the signals send to this ExecutableComponent are simply forwarded to the inner component.
In case the application fails this ExecutionEnvironment logs an error message and rethrows the caught exception.

The getComponentToExecute(ActivityInstance) method may be overridden or reimplemented in order to make it possible to call components which don't have an empty constructor or need any other special treatment upon creation.
Also the initialise() and finish() methods may be overridden if there are components which need any special treatment before or after their execution.

Author:

Andreas Lanz

Nested Class Summary

Nested classes/interfaces inherited from interface de.aristaflow.adept2.model.runtimeenvironment.ExecutableComponent

ExecutableComponent.Signals

Field Summary

Fields

Modifier and Type	Field and Description
protected ExecutableComponent	innerComponent The Executable Component to be executed inside this ID Execution Environment
protected SessionContext	innerSessionContext The Session Context which will be passed along to the inner Component
protected boolean	resume Indicates if the inner Component should be resumed or started from scratch.
protected java.lang.String	savepoint The Savepoint to resume from if resume is true.

Fields inherited from class de.aristaflow.adept2.core.runtimemanager.executionenvironments.ExecutionEnvironment

actData, activityInstance, localisedActInst, logger, sessionContext, SUSPEND_SAVEPOINT

Fields inherited from interface de.aristaflow.adept2.model.runtimeenvironment.ExecutableComponent

CONF_DATA_DIRECTORY, CONF_LIB_DIRECTORY, CONF_LOG_DIRECTORY, UNLOADING_CLASS_METHOD

Constructor Summary

Constructors

Constructor and Description
IDExecutionEnvironment(ActivityInstance activityInstance) Creates a new IDExecutionEnvironment for the designated activity instance.

Method Summary

Modifier and Type	Method and Description
boolean	close() Returns false - overwrite this method to support closing.
void	commit() Throws an IsNotSupportedException - overwrite this method to support committing.
protected void	finish() Finishes the execution of the inner component by resetting context fields and logging an info message.
protected ExecutableComponent	getComponentToExecute(ActivityInstance actInstance) Determines the Executable Component to be executed inside this IDExecutionEnvironment.
void	init(SessionContext sessContext) Initialises this ExecutionEnvironment by setting the session context, the logger field and the activity data.
protected void	initialise() Sets the session context of the component, resumes the component, if appropriate and logs an info.
void	initResume(java.lang.String savepointId, SessionContext sessContext) Does nothing - overwrite this method to support resuming.
boolean	kill() Returns false - overwrite this method to support killing.
Vote	prepareCommit() Throws an IsNotSupportedException - overwrite this method to support Two-phase-commit.
boolean	reset() Returns false - overwrite this method to support reset.
boolean	rollback() Throws an IsNotSupportedException - overwrite this method to support rolling back.
void	run() Resembles Runnable.run() except that this method is expected to throw exceptions indicating that the environment was unexpected or an internal failure occurred.
boolean	signal(int signal) Returns false - overwrite this method to support signalling.
boolean	suspend() Returns false - overwrite this method to support suspending.

Methods inherited from class de.aristaflow.adept2.core.runtimemanager.executionenvironments.ExecutionEnvironment

createActivityData, getApplicationState, getApplicationState, getRawApplicationState, getRawApplicationState, requireGUIContext, setApplicationState, setApplicationState, setRawApplicationState, setRawApplicationState

Methods inherited from class java.lang.Object

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

Field Detail

innerComponent

protected ExecutableComponent innerComponent

The Executable Component to be executed inside this ID Execution Environment

innerSessionContext

protected SessionContext innerSessionContext

The Session Context which will be passed along to the inner Component

resume

protected boolean resume

Indicates if the inner Component should be resumed or started from scratch.

savepoint

protected java.lang.String savepoint

The Savepoint to resume from if resume is true.

Constructor Detail

IDExecutionEnvironment

public IDExecutionEnvironment(ActivityInstance activityInstance)

Creates a new IDExecutionEnvironment for the designated activity instance. The constructor sets the necessary fields by calling the constructor of the superclass.
After that it creates the inner Component to be executed by calling getComponentToExecute(ActivityInstance)

Parameters:

activityInstance - The activity instance for this IDExecutionEnvironment which is also the activity instance for the inner Component.

Throws:

ApplicationEnvironmentException - if any problems occur while instantiating the inner class

Method Detail

getComponentToExecute

protected ExecutableComponent getComponentToExecute(ActivityInstance actInstance)

Determines the Executable Component to be executed inside this IDExecutionEnvironment.

Parameters:

actInstance - the activity instance for which the Executable Component should created. The get("ComponentURI") is used for retrieving the Component to be Executed.

Returns:

An instance of the Component to be executed by this ID Runtime Environment

Throws:

ApplicationEnvironmentException - if anything goes wrong during the instantiation of the class specified by get("ComponentURI")

init

public void init(SessionContext sessContext)

Description copied from class: ExecutionEnvironment

Initialises this ExecutionEnvironment by setting the session context, the logger field and the activity data. These fields are not available before! Therefore you should call this method very early when initialising or initialising for resume.

Initialises and prepares the execution of the application and provides all necessary data which maybe necessary for this. This method or ExecutableComponent.initResume(String, SessionContext) is only called once in the lifetime of an executable component. One of these methods is guaranteed to be called before calling any other method.

When leaving this method the execution has to be completely prepared. This includes for instance the availability of the GUI in the GUI context, which is necessary for Web applications with HTML-UI.

Specified by:

init in interface ExecutableComponent

Overrides:

init in class ExecutionEnvironment

Parameters:

sessContext - The session context to associate with this ExecutionEnvironment.

initResume

public void initResume(java.lang.String savepointId,
                       SessionContext sessContext)

Description copied from class: ExecutionEnvironment

Does nothing - overwrite this method to support resuming.
Note that this does neither set the session context nor the logger.

Initialises and prepares the resuming of the application and provides all necessary data which maybe necessary for this. This method or ExecutableComponent.init(SessionContext) is only called once in the lifetime of an executable component. One of these methods is guaranteed to be called before calling any other method.

When leaving this method the execution has to be completely prepared for resuming. That is, the state of the application has to be restored. This includes the GUI.

Usually this method will delegate also call ExecutableComponent.init(SessionContext).

Specified by:

initResume in interface ExecutableComponent

Overrides:

initResume in class ExecutionEnvironment

Parameters:

savepointId - The identifier of the savepoint at which the application should resume. This must not be null, but it may be the empty string.

sessContext - The session context in which the component is to be executed.

run

public void run()

Description copied from interface: ExecutableComponent

Resembles Runnable.run() except that this method is expected to throw exceptions indicating that the environment was unexpected or an internal failure occurred. Both exceptions as well as RuntimeException will set the corresponding process activity to FAILED.

Specified by:

run in interface ExecutableComponent

Specified by:

run in class ExecutionEnvironment

close

public boolean close()

Description copied from class: ExecutionEnvironment

Returns false - overwrite this method to support closing.

Instructs the component to terminate. Within this method the component should deallocate all allocated resources.

Specified by:

close in interface ExecutableComponent

Overrides:

close in class ExecutionEnvironment

Returns:

false

reset

public boolean reset()

Description copied from class: ExecutionEnvironment

Returns false - overwrite this method to support reset.

Instructs the component to reset. This is quite similar to ExecutableComponent.kill() but the application does not fail but terminate normally (by calling RuntimeEnvironment.applicationReset(). The component will be re-initialised and executed again later.

Specified by:

reset in interface ExecutableComponent

Overrides:

reset in class ExecutionEnvironment

Returns:

false

signal

public boolean signal(int signal)

Description copied from class: ExecutionEnvironment

Returns false - overwrite this method to support signalling.

Signals an event to the application.

Specified by:

signal in interface ExecutableComponent

Overrides:

signal in class ExecutionEnvironment

Parameters:

signal - Ignored.

Returns:

false

See Also:

for possible signals. Usually the ones that have corresponding methods, e. g. {@link Signals#SUSPEND} or {@link Signals#CLOSE}, will not be signaled via this method.

suspend

public boolean suspend()

Description copied from class: ExecutionEnvironment

Returns false - overwrite this method to support suspending.

Instructs the component to store its internal state to the data context and to terminate at once. The application should be able to continue its job later when resuming.

Specified by:

suspend in interface ExecutableComponent

Overrides:

suspend in class ExecutionEnvironment

Returns:

false

kill

public boolean kill()

Description copied from class: ExecutionEnvironment

Returns false - overwrite this method to support killing.

Enforces the application to abort its execution at once. In the case of running a internal transaction application should abort the transaction and should rollback. Within this method the component should deallocate all allocated resources.

Specified by:

kill in interface ExecutableComponent

Overrides:

kill in class ExecutionEnvironment

Returns:

false

prepareCommit

public Vote prepareCommit()
                   throws IsNotSupportedException

Description copied from class: ExecutionEnvironment

Throws an IsNotSupportedException - overwrite this method to support Two-phase-commit.

Instructs the component to vote for Commit or Abort of the distributed transaction it participates in and to prepare a commit.

Specified by:

prepareCommit in interface ExecutableComponent

Overrides:

prepareCommit in class ExecutionEnvironment

Returns:

Nothing, since an IsNotSupportedException is always thrown.

Throws:

IsNotSupportedException - This exception is always thrown.

rollback

public boolean rollback()
                 throws IsNotSupportedException

Description copied from class: ExecutionEnvironment

Throws an IsNotSupportedException - overwrite this method to support rolling back.

Instructs the component to undo all its modifications done within the current transaction. This method has to be implemented in case the application is resettable.

Specified by:

rollback in interface ExecutableComponent

Overrides:

rollback in class ExecutionEnvironment

Returns:

Nothing, since an IsNotSupportedException is always thrown.

Throws:

IsNotSupportedException - This exception is always thrown.

commit

public void commit()
            throws IsNotSupportedException

Description copied from class: ExecutionEnvironment

Throws an IsNotSupportedException - overwrite this method to support committing.

Instructs the component to commit its modifications not managed by ADEPT.

Specified by:

commit in interface ExecutableComponent

Overrides:

commit in class ExecutionEnvironment

Throws:

IsNotSupportedException - This exception is always thrown.

initialise

protected void initialise()

Sets the session context of the component, resumes the component, if appropriate and logs an info.
This is the first method called in the lifetime of this "executor".

finish

protected void finish()

Finishes the execution of the inner component by resetting context fields and logging an info message.
This method is the last method called in the lifetime of this "executor".