parameter-object/src/main/java/com/iluwatar/parameter/object/App.java - master - githubmirror/java-design-patterns

parameter-object/src/main/java/com/iluwatar/parameter/object/App.java
60 строк3 KB
Ilkka Seppälä
deps: Refactor dependencies (#3224)
29 мар 2025, 20:34
29 мар 2025, 20:340ca162a
/*
 * 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.parameter.object;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * The syntax of Java language doesn’t allow you to declare a method with a predefined value for a
 * parameter. Probably the best option to achieve default method parameters in Java is by using the
 * method overloading. Method overloading allows you to declare several methods with the same name
 * but with a different number of parameters. But the main problem with method overloading as a
 * solution for default parameter values reveals itself when a method accepts multiple parameters.
 * Creating an overloaded method for each possible combination of parameters might be cumbersome. To
 * deal with this issue, the Parameter Object pattern is used. The Parameter Object is simply a
 * wrapper object for all parameters of a method. It is nothing more than just a regular POJO. The
 * advantage of the Parameter Object over a regular method parameter list is the fact that class
 * fields can have default values. Once the wrapper class is created for the method parameter list,
 * a corresponding builder class is also created. Usually it's an inner static class. The final step
 * is to use the builder to construct a new parameter object. For those parameters that are skipped,
 * their default values are going to be used.
 */
public class App {

  private static final Logger LOGGER = LoggerFactory.getLogger(App.class);

  /**
   * Program entry point.
   *
   * @param args command line args
   */
  public static void main(String[] args) {
    ParameterObject params =
        ParameterObject.newBuilder().withType("sneakers").sortBy("brand").build();
    LOGGER.info(params.toString());
    LOGGER.info(new SearchService().search(params));
  }
}