MultiCallback.java
/*
** Module : MultiCallback.java
** Abstract : Multiple service callbacks.
**
** Copyright (c) 2017, Golden Code Development Corporation.
**
** -#- -I- --Date-- --------------------------------Description-----------------------------------
** 001 HC 20170612 Initial version.
*/
/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero General Public License as
** published by the Free Software Foundation, either version 3 of the
** License, or (at your option) any later version.
**
** This program 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 Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
**
** Additional terms under GNU Affero GPL version 3 section 7:
**
** Under Section 7 of the GNU Affero GPL version 3, the following additional
** terms apply to the works covered under the License. These additional terms
** are non-permissive additional terms allowed under Section 7 of the GNU
** Affero GPL version 3 and may not be removed by you.
**
** 0. Attribution Requirement.
**
** You must preserve all legal notices or author attributions in the covered
** work or Appropriate Legal Notices displayed by works containing the covered
** work. You may not remove from the covered work any author or developer
** credit already included within the covered work.
**
** 1. No License To Use Trademarks.
**
** This license does not grant any license or rights to use the trademarks
** Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
** of Golden Code Development Corporation. You are not authorized to use the
** name Golden Code, FWD, or the names of any author or contributor, for
** publicity purposes without written authorization.
**
** 2. No Misrepresentation of Affiliation.
**
** You may not represent yourself as Golden Code Development Corporation or FWD.
**
** You may not represent yourself for publicity purposes as associated with
** Golden Code Development Corporation, FWD, or any author or contributor to
** the covered work, without written authorization.
**
** 3. No Misrepresentation of Source or Origin.
**
** You may not represent the covered work as solely your work. All modified
** versions of the covered work must be marked in a reasonable way to make it
** clear that the modified work is not originating from Golden Code Development
** Corporation or FWD. All modified versions must contain the notices of
** attribution required in this license.
*/
package com.goldencode.p2j.admin.client;
import com.goldencode.p2j.admin.client.application.*;
import com.goldencode.p2j.admin.shared.*;
import java.util.*;
import java.util.logging.*;
/**
* The class allows to issue multiple asynchronous service calls and handle results when all
* calls finish.
*/
public class MultiCallback
{
/** Logger */
private Logger log = Logger.getLogger(MultiCallback.class.getSimpleName());
/** Admin service reference */
private AdminServiceAsync adm;
/** Alarm service reference */
private Alarm alarm;
/* index 0 - Child, 1 - result, 2 - exception */
private ArrayList<AdminCallback> callbacks = new ArrayList<>();
/** The number of finished calls */
private int callbacksDone;
/** The handler called when all calls finish */
private Runnable doneHandler;
/**
* Default ctor.
*/
public MultiCallback()
{
}
/**
* Ctor.
*
* @param adm
* Admin service reference
*
* @param alarm
* Alarm service reference
*/
public MultiCallback(AdminServiceAsync adm, Alarm alarm)
{
this.adm = adm;
this.alarm = alarm;
}
/**
* Creates new instance of {@link AdminCallback} that can be used in a service call.
*
* @param <T>
* The result type.
*
* @return {@link AdminCallback} reference
*/
public <T> AdminCallback<T> newCallback()
{
AdminCallback<T> cb = new AdminCallback<T>(adm, null)
{
@Override
public void onDone(T result)
{
childFinished(this);
}
};
callbacks.add(cb);
return cb;
}
/**
* Takes a {@link Runnable} that will be called when all service calls finish.
*
* @param run
* A {@link Runnable}.
*/
public void onDone(Runnable run)
{
doneHandler = run;
}
/**
* Returns <code>true</code> if all the service calls succeed.
*
* @return success flag
*/
public boolean isSuccess()
{
boolean isSuccess = true;
for (AdminCallback c : callbacks)
{
isSuccess &= c.isSuccess();
}
return isSuccess;
}
/**
* Returns all the server messages of all the failed callbacks.
*
* @return list of server messages, an empty list if there are no messages
*/
public List<String> getServerMessages()
{
List<String> messages = new ArrayList<>();
for (AdminCallback c : callbacks)
{
messages.addAll(c.getServerMessages());
}
return messages;
}
/**
* All the exceptions of all the failed service calls.
*
* @return list of exceptions or an empty list if no exceptions
*/
public List<Throwable> getExceptions()
{
ArrayList<Throwable> callbackExceptions = new ArrayList<>();
for (AdminCallback c : callbacks)
{
Throwable t = c.getException();
if (t != null)
{
callbackExceptions.add(t);
}
}
return callbackExceptions;
}
/**
* Called when all the child callbacks have finished.
*
* @param doneHandler
* The runnable called when all the results are processed.
*/
protected void handleAllFinished(Runnable doneHandler)
{
if (isSuccess())
{
// this is a success
if (doneHandler != null)
{
doneHandler.run();
}
return;
}
List<String> messages = getServerMessages();
List<Throwable> callbackExceptions = getExceptions();
if (!callbackExceptions.isEmpty())
{
String msg = "Server call error";
log.severe(msg);
for (Throwable t : callbackExceptions)
{
log.log(Level.SEVERE, "", t);
}
messages.add(0, msg);
}
if (alarm != null && !messages.isEmpty())
{
alarm.ring(messages, doneHandler);
}
else
{
if (doneHandler != null)
{
doneHandler.run();
}
}
}
/**
* A handler of single service result.
*
* @param cb
* An {@link AdminCallback}.
*/
private synchronized void childFinished(AdminCallback cb)
{
callbacksDone++;
if (callbacksDone < callbacks.size())
{
// not all callbacks have finished
return;
}
handleAllFinished(doneHandler);
}
}