Rafael del Nero
Java Developer
Rafael del Nero is a Java Champion and Oracle Ace, creator of the Java Challengers initiative, and a quiz master in the Oracle Dev Gym. Rafael is the author of "Java Challengers" and "Golden Lessons." He believes there are many techniques involved in creating high-quality software that developers are often unaware of. His purpose is to help Java developers use better programming practices to code quality software for stress-free projects with fewer bugs.
All about Java class loaders
Here's a quick look at the three types of class loaders and everything you need to know to work with them in your Java programs.
How to use ForkJoinPool in Java
Use ForkJoinPool to break down computationally intensive tasks and execute them in parallel for better Java application performance.
How to use callbacks in Java
Learn how to use synchronous and asynchronous callbacks in Java—including callbacks with lambda expressions, CompletableFuture, and more.
Intro to the Observable design pattern
The Observable design pattern is found in many Java APIs and in reactive programming. Here's an introduction to the timeless Observable pattern in Java.
Lazy vs. eager instantiation in Java: Which is better?
Learn how to use lazy instantiation and eager instantiation in your Java programs. Which approach is better? It depends on the scenario.
How to use the Command pattern in Java
Learn how to use the Command pattern to encapsulate requests as objects that you can execute alone or in sequence in your Java programs.
Abstract classes vs. interfaces in Java
When should you choose an abstract class over an interface in Java? Take the challenge! Learn the difference between these Java language elements and how to use them in your programs.
Java inheritance vs. composition: How to choose
Compare inheritance and composition, the two fundamental ways to relate Java classes, then practice debugging ClassCastExceptions in Java inheritance.
Does Java pass by reference or pass by value?
You've probably heard that Java passes by value, but what matters is how well you understand the concept and the code. Find out what happens when you pass an object reference to a method in Java.
Comparing Java objects with equals() and hashcode()
What is the contract between equals() and hashcode()? Learn how these methods work together when comparing Java objects.
Polymorphism and inheritance in Java
Challenge yourself, with this brain-teasing introduction to Java method invocation in polymorphic method calls.