com.threerings.presents.util
Class PersistingUnit

java.lang.Object
  com.samskivert.util.Invoker.Unit
      com.threerings.presents.util.PersistingUnit

All Implemented Interfaces:

Runnable

public abstract class PersistingUnit
extends Invoker.Unit

Simplifies a common pattern which is to post an Invoker unit which does some database operation and then calls back to an InvocationService.InvocationListener of some sort. If the database operation fails, the error will be logged and the result listener will be replied to with InvocationCodes.INTERNAL_ERROR.

Field Summary

protected Object[]	_args
protected Exception	_error
protected InvocationService.InvocationListener	_listener
protected Object	_result
protected boolean	_resultSet

Fields inherited from class com.samskivert.util.Invoker.Unit

_name, queueStamp

Constructor Summary

PersistingUnit(InvocationService.InvocationListener listener)

PersistingUnit(String name, InvocationService.InvocationListener listener)

PersistingUnit(String name, InvocationService.InvocationListener listener, Object... args)
Creates a persisting unit with the supplied name and listener and a set of key/value pairs that will be included in the failure message if this unit fails.

Method Summary

protected String	getFailureMessage() Provides a custom failure message in the event that the persistent action fails.
void	handleFailure(Exception error) Handles the failure case by logging the error and reporting an internal error to the listener.
void	handleResult()
void	handleSuccess() Handles the success case, which by default posts a response to a ConfirmListener.
boolean	invoke()
abstract void	invokePersistent() This method is where the unit performs its persistent actions.
protected void	reportRequestProcessed() If the listener is known to be a ConfirmListener, this will cast it and report that the request was processed.
protected void	reportRequestProcessed(Object result) If the listener is known to be a ResultListener, this will cast it and report that the request was processed.
protected void	setResult(Object result) If the service listener is a ResultListener and this method is called, then the given result will be passed along to the listener on success.

Methods inherited from class com.samskivert.util.Invoker.Unit

getDetail, getLongThreshold, run, toString

Methods inherited from class java.lang.Object

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

Field Detail

_listener

protected InvocationService.InvocationListener _listener

_error

protected Exception _error

_args

protected Object[] _args

_resultSet

protected boolean _resultSet

_result

protected Object _result

Constructor Detail

PersistingUnit

public PersistingUnit(InvocationService.InvocationListener listener)

PersistingUnit

public PersistingUnit(String name,
                      InvocationService.InvocationListener listener)

PersistingUnit

public PersistingUnit(String name,
                      InvocationService.InvocationListener listener,
                      Object... args)

Creates a persisting unit with the supplied name and listener and a set of key/value pairs that will be included in the failure message if this unit fails.

Method Detail

invokePersistent

public abstract void invokePersistent()
                               throws Exception

This method is where the unit performs its persistent actions. Any persistence exception will be caught and logged along with the output from getFailureMessage(), if any.

Throws:

Exception

handleSuccess

public void handleSuccess()

Handles the success case, which by default posts a response to a ConfirmListener. If you need something else, or to repond to a ResultListener, you'll need to override this.

handleFailure

public void handleFailure(Exception error)

Handles the failure case by logging the error and reporting an internal error to the listener.

invoke

public boolean invoke()

Specified by:

invoke in class Invoker.Unit

handleResult

public void handleResult()

Overrides:

handleResult in class Invoker.Unit

reportRequestProcessed

protected void reportRequestProcessed()

If the listener is known to be a ConfirmListener, this will cast it and report that the request was processed.

reportRequestProcessed

protected void reportRequestProcessed(Object result)

If the listener is known to be a ResultListener, this will cast it and report that the request was processed.

getFailureMessage

protected String getFailureMessage()

Provides a custom failure message in the event that the persistent action fails. This will be logged along with the exception.

setResult

protected void setResult(Object result)

If the service listener is a ResultListener and this method is called, then the given result will be passed along to the listener on success.