Libraries - Java 8 Lambdas - page 54

Example 4-15. A parent class that overrides the default implementation of welcome
public public class class OverridingParent OverridingParent extends extends ParentImpl {

@Override
public public void void welcome () {

message ( "Class Parent: Hi!" );

}

}

Example 4-16. An example of a concrete method beating a default method
@Test
public

public void void concreteBeatsDefault () {

Parent parent = new new OverridingParent ();

parent . welcome ();
assertEquals ( "Class Parent: Hi!" , parent . getLastMessage ());

}

Here's a situation, presented in Example 4-18 , in which you might not expect the concrete
class to override the default method. OverridingChild inherits both the welcome method
from Child and the welcome method from OverridingParent and doesn't do anything it-
self. OverridingParent is chosen despite OverridingChild (the code in Example 4-17 ) ,
being a more specific type because it's a concrete method from a class rather than a default
method (see Figure 4-5 ).

Example 4-17. Again, our child interface overrides the default welcome method
public public class class OverridingChild OverridingChild extends extends OverridingParent implements implements Child {

}

Example 4-18. An example of a concrete method beating a default method that is more spe-
cific
@Test
public public void void concreteBeatsCloserDefault () {

Child child = new new OverridingChild ();

child . welcome ();
assertEquals ( "Class Parent: Hi!" , child . getLastMessage ());

}