net.markenwerk.commons.interfaces.Handler Maven / Gradle / Ivy
Show all versions of commons-interfaces Show documentation
/*
* Copyright (c) 2015 Torsten Krause, Markenwerk GmbH
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package net.markenwerk.commons.interfaces;
/**
* For an arbitrary process, that may encounter some kind of event and needs to
* delegate the event handling, a {@link Handler} is used, to convey that event
* from the executor of the process (hereafter: executor) back to the initiator
* of the process (hereafter: initiator).
*
*
* Depending on the concrete scenario, the initiator may reuse the same instance
* of {@link Handler} for multiple processes and even for the same executor,
* although the letter is unusual.
*
*
* The executor may or may not call {@link Handler#handle(Object)}.
*
*
* The executor may call {@link Handler#handle(Object)}, more than once,
* depending o the concrete scenario, to convey partial or updated results. This
* should be noted in the contract of the method, that is used to convey the
* {@link Handler} to the executor.
*
*
* The executor must not call {@link Handler#handle(Object)} more than once for
* the same event.
*
* @param
* The type of the event of the process.
* @since 3.0.0
* @author Torsten Krause (tk at markenwerk dot net)
*/
public interface Handler {
/**
* Called by the executor when an event occurs.
*
* @param event
* The event.
*/
public void handle(Event event);
}