/* * 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 default methods. There are two simple rules: *
* System.out.println(new Tuna().swim()); //"Tuna swims under water" output is suspected here
*
*/
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
*
* //"I can swim on the surface of the water." output is suspected here
* System.out.println(new Duck().swim());
*
*/
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());
}
}