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java ( 2341570 ) - com.iluwatar.de ( 2344139 ) stack: com.iluwatar.decorator.App.main(App.java:47) org.codehaus.mojo.exec.ExecJavaMojo.doMain(ExecJavaMojo.java:385) org.codehaus.mojo.exec.ExecJavaMojo.doExec(ExecJavaMojo.java:374) org.codehaus.mojo.exec.ExecJavaMojo.lambda$execute$0(ExecJavaMojo.java:296) java.base/java.lang.Thread.run(Thread.java:840)
/*
 * 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.decorator;

import lombok.extern.slf4j.Slf4j;

/**
 * The Decorator pattern is a more flexible alternative to subclassing. The Decorator class
 * implements the same interface as the target and uses composition to "decorate" calls to the
 * target. Using the Decorator pattern it is possible to change the behavior of the class during
 * runtime.
 *
 * <p>In this example we show how the simple {@link SimpleTroll} first attacks and then flees the
 * battle. Then we decorate the {@link SimpleTroll} with a {@link ClubbedTroll} and perform the
 * attack again. You can see how the behavior changes after the decoration.
 */
@Slf4j
public class App {

  /**
   * Program entry point.
   *
   * @param args command line args
   */
  public static void main(String[] args) {

    // simple troll
    LOGGER.info("A simple looking troll approaches.");
    var troll = new SimpleTroll();
    troll.attack();
    troll.fleeBattle();
    LOGGER.info("Simple troll power: {}.\n", troll.getAttackPower());

    // change the behavior of the simple troll by adding a decorator
    LOGGER.info("A troll with huge club surprises you.");
    var clubbedTroll = new ClubbedTroll(troll);
    clubbedTroll.attack();
    clubbedTroll.fleeBattle();
    LOGGER.info("Clubbed troll power: {}.\n", clubbedTroll.getAttackPower());
  }
}
Variables All
No.FromNameValue
1class@47LOGGERLogger[com.iluwatar.decorator.App]
247args[Ljava.lang.String;@3575f514
END 0 00
Output All Filter Merge
Process FilterThread Filter
2341570 java 2344139 com.iluwatar.de
No.PNPIDTIDTNTLMessage
1java23415702344139com.iluwatar.decom.iluwatar.decorator.AppIA simple looking troll approaches.
2java23415702344139com.iluwatar.decom.iluwatar.decorator.SimpleTrollIThe troll tries to grab you!
3java23415702344139com.iluwatar.decom.iluwatar.decorator.SimpleTrollIThe troll shrieks in horror and runs away!
4java23415702344139com.iluwatar.decom.iluwatar.decorator.AppISimple troll power: 10.
5java23415702344139com.iluwatar.decom.iluwatar.decorator.AppIA troll with huge club surprises you.
6java23415702344139com.iluwatar.decom.iluwatar.decorator.SimpleTrollIThe troll tries to grab you!
7java23415702344139com.iluwatar.decom.iluwatar.decorator.ClubbedTrollIThe troll swings at you with a club!
8java23415702344139com.iluwatar.decom.iluwatar.decorator.SimpleTrollIThe troll shrieks in horror and runs away!
9java23415702344139com.iluwatar.decom.iluwatar.decorator.AppIClubbed troll power: 20.
END 0 0 0 0 0 00
Project:JavaDesignPatterns
Update:20240509
Commit:bf6456ba6
Source Code:decorator
BuildTool:Java17
Compiler:Java17
Runtime:Openjdk17
System:MySystemD
Kernel:Linux5.10.211
Cpu:Intel:Corei7-7700K
Machine:AwesomeMachine