org.springframework.roo.process.manager

Interface ProcessManager

All Superinterfaces:

ProcessManagerStatusProvider

All Known Implementing Classes:

DefaultProcessManager

public interface ProcessManager
extends ProcessManagerStatusProvider

Provides coordinated execution of major ROO operations.

A ProcessManager delivers:

• A well-defined state publication model via ProcessManagerStatusProvider
• Startup-time registration of the initial monitoring requests (after the #completeStartup() method has been called)
• Specific scanning of FileMonitorService at well-defined times
• The ability to execute CommandCallbacks for user-requested operations
• An assurance the above is conducted within a "transaction-like" model

Once constructed, all methods in ProcessManager operate in a "transaction-like" manner. This is achieved by use of a FileManager that shares the same UndoManager.

Once available, a ProcessManager will ordinarily wait for either #backgroundScan() or execute(CommandCallback). It will block until the state of the ProcessManager returns to ProcessManagerStatus.AVAILABLE.

ProcessManager guarantees:

• The status will remain ProcessManagerStatus.STARTING until #completeStartup() has been called. This is intended to allow objects depending on ProcessManager or other MetadataServices to be constructed and register for events. The initial monitoring requests will only be registered during #completeStartup(), which therefore simplifies the design of dependent objects as they generally (i) don't need to retrieve metadata produced before they were listening and (ii) can freely modify the file system pursuant to FileManager with assurance of correct "transaction" behaviour.
• At the end of a successful startup, background scan or command execution, UndoManager.reset() method will be called.
• An uncaught exception will cause UndoManager.undo() to be called (before re-throwing the exception).
• A FileMonitorService.scanAll() will be called after a command is executed, and will continue to be called until such time as it does not return any further changes. Such calls will occur within the scope of the same "transaction" as used for the command.

ProcessManager implementations also guarantee to update ActiveProcessManager whenever running an operation, and clear it when an operation completes.

Since:

1.0

Author:

Ben Alex

Method Summary

Methods

Modifier and Type	Method and Description
<T> T	execute(CommandCallback<T> callback) Execute a user command within a "transaction".
long	getLastScanDuration()
long	getMinimumDelayBetweenScan()
boolean	isDevelopmentMode()
void	setDevelopmentMode(boolean developmentMode)
void	setMinimumDelayBetweenScan(long minimumDelayBetweenScan)
void	terminate() Allows the process manager to terminate gracefully.
void	timerBasedScan()

Methods inherited from interface org.springframework.roo.process.manager.event.ProcessManagerStatusProvider

addProcessManagerStatusListener, getProcessManagerStatus, removeProcessManagerStatusListener

Method Detail

execute

<T> T execute(CommandCallback<T> callback)

Execute a user command within a "transaction". This method blocks until ProcessManagerStatus.AVAILABLE.

This method may throw RuntimeExceptions that occurred while executing.

Type Parameters:

T - the class of the object that CommandCallback.callback() will return (required)

Parameters:

callback - the callback to actually executed (required)

Returns:

the result of executing the callback

getLastScanDuration

long getLastScanDuration()

getMinimumDelayBetweenScan

long getMinimumDelayBetweenScan()

isDevelopmentMode

boolean isDevelopmentMode()

Returns:

true if the system is in development mode, which generally means more detailed diagnostics are requested from add-ons (defaults to false)

setDevelopmentMode

void setDevelopmentMode(boolean developmentMode)

setMinimumDelayBetweenScan

void setMinimumDelayBetweenScan(long minimumDelayBetweenScan)

terminate

void terminate()

Allows the process manager to terminate gracefully. In particular this means any background threads it has started are terminated. It is safe to call this method more than once, but no other method in the process manager need operate correctly after termination.

timerBasedScan

void timerBasedScan()