1 /* 2 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * - Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 11 * - Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * - Neither the name of Oracle nor the names of its 16 * contributors may be used to endorse or promote products derived 17 * from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS 20 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 21 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 26 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 27 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 28 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /** 33 * The sample illustrates the simplest use case of the <b>default methods</b>. 34 * 35 * @author Taras Ledkov 36 */ 37 public class SimplestUsage { 38 39 /** 40 * The Animal interface provides the default implementation 41 * of the {@link #eat} method. 42 */ 43 public interface Animal { 44 45 /** 46 * Return string representation of the eat action for Animal 47 * 48 * @return string representation of the eat action for Animal 49 */ 50 default String eat() { 51 return this.getClass().getSimpleName() 52 + " eats like an ordinary animal"; 53 } 54 } 55 56 /** 57 * The Dog class doesn't have its own implementation of the {@link #eat} 58 * method and uses the default implementation. 59 */ 60 public static class Dog implements Animal { 61 } 62 63 /** 64 * The Mosquito class implements {@link #eat} method, its own implementation 65 * overrides the default implementation. 66 * 67 */ 68 public static class Mosquito implements Animal { 69 70 /** 71 * Return string representation of the eat action for Mosquito 72 * 73 * @return string representation of the eat action for Mosquito 74 */ 75 @Override 76 public String eat() { 77 return "Mosquito consumes blood"; 78 } 79 } 80 81 /** 82 * Illustrate behavior of the classes: {@link Dog} and {@link Mosquito} 83 * 84 * @param args command-line arguments 85 */ 86 public static void main(String[] args) { 87 // "Dog eats like an ordinary animal" output is suspected here 88 System.out.println(new Dog().eat()); 89 90 // "Mosquito consumes blood" output is suspected here 91 System.out.println(new Mosquito().eat()); 92 } 93 }