App.java

/**
 * The MIT License
 * Copyright (c) 2014-2016 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.resource.acquisition.is.initialization;

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

/**
 * 
 * Resource Acquisition Is Initialization pattern was developed for exception safe resource
 * management by C++ creator Bjarne Stroustrup.
 * <p>
 * In RAII resource is tied to object lifetime: resource allocation is done during object creation
 * while resource deallocation is done during object destruction.
 * <p>
 * In Java RAII is achieved with try-with-resources statement and interfaces {@link Closeable} and
 * {@link AutoCloseable}. The try-with-resources statement ensures that each resource is closed at
 * the end of the statement. Any object that implements {@link java.lang.AutoCloseable}, which
 * includes all objects which implement {@link java.io.Closeable}, can be used as a resource.
 *
 * In this example, {@link SlidingDoor} implements {@link AutoCloseable} and {@link TreasureChest}
 * implements {@link Closeable}. Running the example, we can observe that both resources are
 * automatically closed.
 * <p>
 * http://docs.oracle.com/javase/7/docs/technotes/guides/language/try-with-resources.html
 *
 */
public class App {

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

  /**
   * Program entry point
   */
  public static void main(String[] args) throws Exception {

    try (SlidingDoor slidingDoor = new SlidingDoor()) {
      LOGGER.info("Walking in.");
    }

    try (TreasureChest treasureChest = new TreasureChest()) {
      LOGGER.info("Looting contents.");
    }
  }
}