DZone
Thanks for visiting DZone today,
Edit Profile
  • Manage Email Subscriptions
  • How to Post to DZone
  • Article Submission Guidelines
Sign Out View Profile
  • Post an Article
  • Manage My Drafts
Over 2 million developers have joined DZone.
Log In / Join
Please enter at least three characters to search
Refcards Trend Reports
Events Video Library
Refcards
Trend Reports

Events

View Events Video Library

Zones

Culture and Methodologies Agile Career Development Methodologies Team Management
Data Engineering AI/ML Big Data Data Databases IoT
Software Design and Architecture Cloud Architecture Containers Integration Microservices Performance Security
Coding Frameworks Java JavaScript Languages Tools
Testing, Deployment, and Maintenance Deployment DevOps and CI/CD Maintenance Monitoring and Observability Testing, Tools, and Frameworks
Culture and Methodologies
Agile Career Development Methodologies Team Management
Data Engineering
AI/ML Big Data Data Databases IoT
Software Design and Architecture
Cloud Architecture Containers Integration Microservices Performance Security
Coding
Frameworks Java JavaScript Languages Tools
Testing, Deployment, and Maintenance
Deployment DevOps and CI/CD Maintenance Monitoring and Observability Testing, Tools, and Frameworks

Last call! Secure your stack and shape the future! Help dev teams across the globe navigate their software supply chain security challenges.

Modernize your data layer. Learn how to design cloud-native database architectures to meet the evolving demands of AI and GenAI workloads.

Releasing software shouldn't be stressful or risky. Learn how to leverage progressive delivery techniques to ensure safer deployments.

Avoid machine learning mistakes and boost model performance! Discover key ML patterns, anti-patterns, data strategies, and more.

Related

  • Injecting Implementations With Jakarta CDI Using Polymorphism
  • Understanding Java Signals
  • Introduction to Polymorphism With Database Engines in NoSQL Using Jakarta NoSQL
  • Implementation Best Practices: Microservice API With Spring Boot

Trending

  • How Large Tech Companies Architect Resilient Systems for Millions of Users
  • How AI Is Changing the Way Developers Write Code
  • How to Build Local LLM RAG Apps With Ollama, DeepSeek-R1, and SingleStore
  • How the Go Runtime Preempts Goroutines for Efficient Concurrency
  1. DZone
  2. Coding
  3. Java
  4. Optional Parameters in Java 8 Lambda Expressions

Optional Parameters in Java 8 Lambda Expressions

By 
Jochen Bedersdorfer user avatar
Jochen Bedersdorfer
·
Jul. 07, 15 · Code Snippet
Likes (1)
Comment
Save
Tweet
Share
7.3K Views

Join the DZone community and get the full member experience.

Join For Free

Yeah, they don't really exist, but we can use polymorphism, method overloading and default methods instead to make it a bit more convenient to use our APIs.

As an example, here's an event bus implementation where I can register event handlers with an optional header parameter.

  Bus bus = new Bus();
  bus.register(event -> System.out.println("I gots an event"));
  bus.register((event,header) -> System.out.println("I gots an event w/ header"));

Here are the dirty details on how you can do this (and - when dispatching - events, use default methods to avoid type coercion.

Java (programming language) Event Polymorphism (computer science) Implementation

Opinions expressed by DZone contributors are their own.

Related

  • Injecting Implementations With Jakarta CDI Using Polymorphism
  • Understanding Java Signals
  • Introduction to Polymorphism With Database Engines in NoSQL Using Jakarta NoSQL
  • Implementation Best Practices: Microservice API With Spring Boot

Partner Resources

×

Comments
Oops! Something Went Wrong

The likes didn't load as expected. Please refresh the page and try again.

ABOUT US

  • About DZone
  • Support and feedback
  • Community research
  • Sitemap

ADVERTISE

  • Advertise with DZone

CONTRIBUTE ON DZONE

  • Article Submission Guidelines
  • Become a Contributor
  • Core Program
  • Visit the Writers' Zone

LEGAL

  • Terms of Service
  • Privacy Policy

CONTACT US

  • 3343 Perimeter Hill Drive
  • Suite 100
  • Nashville, TN 37211
  • support@dzone.com

Let's be friends:

Likes
There are no likes...yet! 👀
Be the first to like this post!
It looks like you're not logged in.
Sign in to see who liked this post!