Class DefaultMethodExamples

java.lang.Object

net.jrodolfo.java_evolution.java08.DefaultMethodExamples

public class DefaultMethodExamples
extends Object

Demonstrates default methods, introduced in Java 8 so interfaces could evolve without forcing every existing implementation to add new methods immediately.

Before Java 8, adding a method to an interface was a breaking change for every implementation. That was a serious problem for old, widely used JDK interfaces because the platform needed to add new behavior while preserving compatibility with existing code.

Default methods solve this by allowing an interface to provide an inherited method body. Implementations can accept the default behavior or override it when they need something more specific.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	DefaultMethodExamples.AdminUser	Implementation that overrides a default method while keeping the others.
static interface	DefaultMethodExamples.Named	Interface with one abstract method and two default methods.
static class	DefaultMethodExamples.RegularUser	Implementation that inherits all default behavior from DefaultMethodExamples.Named.

Constructor Summary

Constructors

Constructor	Description
DefaultMethodExamples()

Method Summary

Modifier and Type	Method	Description
DefaultMethodExamples.Named	adminUser(String name)	Creates a user that overrides one default method.
DefaultMethodExamples.Named	regularUser(String name)	Creates a user that relies on the default methods from DefaultMethodExamples.Named.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

DefaultMethodExamples

public DefaultMethodExamples()

Method Details

regularUser

public DefaultMethodExamples.Named regularUser(String name)

Creates a user that relies on the default methods from DefaultMethodExamples.Named.

Parameters:

name - the user's name

Returns:

a user implementation with no custom default-method overrides

adminUser

public DefaultMethodExamples.Named adminUser(String name)

Creates a user that overrides one default method.

Parameters:

name - the user's name

Returns:

a user implementation with a custom display name