1 /* 2 * Copyright (c) 2014, 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 public class SimplestUsage { 36 37 /** 38 * The Animal interface provides the default implementation 39 * of the {@link #eat} method. 40 */ 41 public interface Animal { 42 43 /** 44 * Return string representation of the eat action for Animal 45 * 46 * @return string representation of the eat action for Animal 47 */ eat()48 default String eat() { 49 return this.getClass().getSimpleName() 50 + " eats like an ordinary animal"; 51 } 52 } 53 54 /** 55 * The Dog class doesn't have its own implementation of the {@link #eat} 56 * method and uses the default implementation. 57 */ 58 public static class Dog implements Animal { 59 } 60 61 /** 62 * The Mosquito class implements {@link #eat} method, its own implementation 63 * overrides the default implementation. 64 * 65 */ 66 public static class Mosquito implements Animal { 67 68 /** 69 * Return string representation of the eat action for Mosquito 70 * 71 * @return string representation of the eat action for Mosquito 72 */ 73 @Override eat()74 public String eat() { 75 return "Mosquito consumes blood"; 76 } 77 } 78 79 /** 80 * Illustrate behavior of the classes: {@link Dog} and {@link Mosquito} 81 * 82 * @param args command-line arguments 83 */ main(String[] args)84 public static void main(String[] args) { 85 // "Dog eats like an ordinary animal" is output 86 System.out.println(new Dog().eat()); 87 88 // "Mosquito consumes blood" is output 89 System.out.println(new Mosquito().eat()); 90 } 91 } 92