You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
143 lines
4.9 KiB
143 lines
4.9 KiB
/*
|
|
* Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* - Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
*
|
|
* - Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* - Neither the name of Oracle nor the names of its
|
|
* contributors may be used to endorse or promote products derived
|
|
* from this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
|
|
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
|
|
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
|
|
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
|
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
|
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
|
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
|
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
/**
|
|
* The sample illustrates rules to resolve conflicts between inheritance
|
|
* candidates with <b>default methods</b>. There are two simple rules:
|
|
* <ul>
|
|
* <li>Class wins. If the superclass has a concrete or abstract declaration of
|
|
* this method, then it is preferred over all defaults.</li>
|
|
* <li>Subtype wins. If an interface extends another interface, and both provide
|
|
* a default, then the more specific interface wins. </li>
|
|
* </ul>
|
|
*/
|
|
public class Inheritance {
|
|
|
|
/**
|
|
* The behavior of an creature that can swim
|
|
*/
|
|
public interface Swimable {
|
|
|
|
/**
|
|
* Return string representation of the swim action for a creature that
|
|
* can swim
|
|
*
|
|
* @return string representation of the swim action for a creature
|
|
* that can swim
|
|
*/
|
|
default String swim() {
|
|
return "I can swim.";
|
|
}
|
|
}
|
|
|
|
/**
|
|
* The abstract class that overrides {@link #swim} method
|
|
*/
|
|
public abstract static class Fish implements Swimable {
|
|
|
|
/**
|
|
* Return string representation of the swim action for a fish
|
|
*
|
|
* @return string representation of the swim action for a fish
|
|
*/
|
|
@Override
|
|
public String swim() {
|
|
return this.getClass().getSimpleName() + " swims under water";
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This class is used for the illustration rule of 1. See the source code
|
|
* of the {@link #main} method.
|
|
* <pre>
|
|
* System.out.println(new Tuna().swim()); //"Tuna swims under water" output is suspected here
|
|
* </pre>
|
|
*/
|
|
public static class Tuna extends Fish implements Swimable {
|
|
}
|
|
|
|
/**
|
|
* The behavior of an creature that can dive: the interface that overrides
|
|
* {@link #swim} method (subtype of {@link Swimable})
|
|
*/
|
|
public interface Diveable extends Swimable {
|
|
|
|
/**
|
|
* Return string representation of the swim action for a creature that
|
|
* can dive
|
|
*
|
|
* @return string representation of the swim action for a creature
|
|
* that can dive
|
|
*/
|
|
@Override
|
|
default String swim() {
|
|
return "I can swim on the surface of the water.";
|
|
}
|
|
|
|
/**
|
|
* Return string representation of the dive action for a creature that
|
|
* can dive
|
|
*
|
|
* @return string representation of the dive action for a creature
|
|
* that can dive
|
|
*/
|
|
default String dive() {
|
|
return "I can dive.";
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This class is used for the illustration of rule 2. See the source code
|
|
* of the {@link #main} method
|
|
* <pre>
|
|
* //"I can swim on the surface of the water." output is suspected here
|
|
* System.out.println(new Duck().swim());
|
|
* </pre>
|
|
*/
|
|
public static class Duck implements Swimable, Diveable {
|
|
}
|
|
|
|
/**
|
|
* Illustrate behavior of the classes: {@link Tuna} and {@link Duck}
|
|
*
|
|
* @param args command line arguments
|
|
*/
|
|
public static void main(final String[] args) {
|
|
// Illustrates rule 1. The Fish.swim() implementation wins
|
|
//"Tuna swims under water" is output
|
|
System.out.println(new Tuna().swim());
|
|
|
|
// Illustrates rule 2. The Diveable.swim() implementation wins
|
|
//"I can swim on the surface of the water." is output
|
|
System.out.println(new Duck().swim());
|
|
}
|
|
}
|