/*
* This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt).
*
* The MIT License
* Copyright © 2014-2022 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.
*/
package com.iluwatar.dependency.injection;
import com.google.inject.Guice;
/**
* Dependency Injection pattern deals with how objects handle their dependencies. The pattern
* implements so-called inversion of control principle. Inversion of control has two specific rules:
* - High-level modules should not depend on low-level modules. Both should depend on abstractions.
* - Abstractions should not depend on details. Details should depend on abstractions.
*
* In this example we show you three different wizards. The first one ({@link SimpleWizard}) is
* a naive implementation violating the inversion of control principle. It depends directly on a
* concrete implementation which cannot be changed.
*
*
The second and third wizards({@link AdvancedWizard} and {@link AdvancedSorceress}) are more
* flexible. They do not depend on any concrete implementation but abstraction. They utilize
* Dependency Injection pattern allowing their {@link Tobacco} dependency to be injected through
* constructor ({@link AdvancedWizard}) or setter ({@link AdvancedSorceress}). This way, handling
* the dependency is no longer the wizard's responsibility. It is resolved outside the wizard
* class.
*
*
The fourth example takes the pattern a step further. It uses Guice framework for Dependency
* Injection. {@link TobaccoModule} binds a concrete implementation to abstraction. Injector is then
* used to create {@link GuiceWizard} object with correct dependencies.
*/
public class App {
/**
* Program entry point.
*
* @param args command line args
*/
public static void main(String[] args) {
var simpleWizard = new SimpleWizard();
simpleWizard.smoke();
var advancedWizard = new AdvancedWizard(new SecondBreakfastTobacco());
advancedWizard.smoke();
var advancedSorceress = new AdvancedSorceress();
advancedSorceress.setTobacco(new SecondBreakfastTobacco());
advancedSorceress.smoke();
var injector = Guice.createInjector(new TobaccoModule());
var guiceWizard = injector.getInstance(GuiceWizard.class);
guiceWizard.smoke();
}
}