2020-05-01 08:04:45 +00:00

69 lines
2.8 KiB
Java

/*
* The MIT License
* Copyright © 2014-2019 Ilkka Seppälä
*
* 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.
*/
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Created by Alexis on 28-Apr-17. With Marker interface idea is to make empty interface and extend
* it. Basically it is just to identify the special objects from normal objects. Like in case of
* serialization , objects that need to be serialized must implement serializable interface (it is
* empty interface) and down the line writeObject() method must be checking if it is a instance of
* serializable or not.
*
* <p>Marker interface vs annotation Marker interfaces and marker annotations both have their uses,
* neither of them is obsolete or always better then the other one. If you want to define a type
* that does not have any new methods associated with it, a marker interface is the way to go. If
* you want to mark program elements other than classes and interfaces, to allow for the possibility
* of adding more information to the marker in the future, or to fit the marker into a framework
* that already makes heavy use of annotation types, then a marker annotation is the correct choice
*/
public class App {
/**
* Program entry point.
*
* @param args command line args
*/
public static void main(String[] args) {
final Logger logger = LoggerFactory.getLogger(App.class);
var guard = new Guard();
var thief = new Thief();
//noinspection ConstantConditions
if (guard instanceof Permission) {
guard.enter();
} else {
logger.info("You have no permission to enter, please leave this area");
}
//noinspection ConstantConditions
if (thief instanceof Permission) {
thief.doNothing();
} else {
thief.doNothing();
}
}
}