Michael Bayne
8f81893a0c
unit's public API. handleResult() and handleFailure() could also be protected but we're adapting Invoker.Unit to something that appears to provide a different (persistence friendly) public API even though the invoker doesn't actually call it, but rather the normal Unit public methods call the new public methods. But we still want to maintain the "feel" of these being the PersistingUnit's "main thing. git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@4839 542714f4-19e9-0310-aa3c-eee0fc999fb1
108 lines
3.3 KiB
Java
108 lines
3.3 KiB
Java
//
|
|
// $Id$
|
|
//
|
|
// Narya library - tools for developing networked games
|
|
// Copyright (C) 2002-2007 Three Rings Design, Inc., All Rights Reserved
|
|
// http://www.threerings.net/code/narya/
|
|
//
|
|
// This library is free software; you can redistribute it and/or modify it
|
|
// under the terms of the GNU Lesser General Public License as published
|
|
// by the Free Software Foundation; either version 2.1 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// This library is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
// Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public
|
|
// License along with this library; if not, write to the Free Software
|
|
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
|
|
package com.threerings.presents.util;
|
|
|
|
import com.samskivert.io.PersistenceException;
|
|
import com.samskivert.util.Invoker;
|
|
|
|
import com.threerings.presents.Log;
|
|
import com.threerings.presents.client.InvocationService;
|
|
import com.threerings.presents.data.InvocationCodes;
|
|
|
|
/**
|
|
* Simplifies a common pattern which is to post an {@link Invoker} unit which does some database
|
|
* operation and then calls back to an {@link InvocationService.InvocationListener} of some
|
|
* sort. If the database operation fails, the error will be logged and the result listener will be
|
|
* replied to with {@link InvocationCodes#INTERNAL_ERROR}.
|
|
*/
|
|
public abstract class PersistingUnit extends Invoker.Unit
|
|
{
|
|
public PersistingUnit (InvocationService.InvocationListener listener)
|
|
{
|
|
this("UnknownPersistingUnit", listener);
|
|
}
|
|
|
|
public PersistingUnit (String name, InvocationService.InvocationListener listener)
|
|
{
|
|
super(name);
|
|
_listener = listener;
|
|
}
|
|
|
|
/**
|
|
* This method is where the unit performs its persistent actions. Any persistence exception
|
|
* will be caught and logged along with the output from {@link #getFailureMessage}, if any.
|
|
*/
|
|
public abstract void invokePersistent ()
|
|
throws PersistenceException;
|
|
|
|
/**
|
|
* Handles the success case, which by default is to do nothing.
|
|
*/
|
|
public void handleSuccess ()
|
|
{
|
|
}
|
|
|
|
/**
|
|
* Handles the failure case by logging the error and reporting an internal error to the
|
|
* listener.
|
|
*/
|
|
public void handleFailure (PersistenceException error)
|
|
{
|
|
Log.warning(getFailureMessage());
|
|
Log.logStackTrace(error);
|
|
_listener.requestFailed(InvocationCodes.INTERNAL_ERROR);
|
|
}
|
|
|
|
@Override // from Invoker.Unit
|
|
public boolean invoke ()
|
|
{
|
|
try {
|
|
invokePersistent();
|
|
} catch (PersistenceException pe) {
|
|
_error = pe;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
@Override // from Invoker.Unit
|
|
public void handleResult ()
|
|
{
|
|
if (_error != null) {
|
|
handleFailure(_error);
|
|
} else {
|
|
handleSuccess();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Provides a custom failure message in the event that the persistent action fails. This will
|
|
* be logged along with the exception.
|
|
*/
|
|
protected String getFailureMessage ()
|
|
{
|
|
return this + " failed.";
|
|
}
|
|
|
|
protected InvocationService.InvocationListener _listener;
|
|
protected PersistenceException _error;
|
|
}
|