Batch Processing with MongoDB and Jakarta EE: From Customer Segmentation to Scalable Workflows
Build a Jakarta Batch job that reclassifies e-commerce customers into tiers on MongoDB, with a Jakarta Faces preview flow before execution.
Tutorials
OpenID Federation with pac4j and CAS
Build an OpenID Federation with pac4j as the Java relying party and Apereo CAS as both OpenID Provider and trust anchor.
How to Secure a Spring Boot Application with OpenID Connect and pac4j
Add OpenID Connect login to Spring Boot with pac4j: Maven setup, provider configuration, user profiles and logout.
Java Stream Gatherers: From Built-in Patterns to Custom Pipeline Mechanics
Explore Java Stream Gatherers (JEP 485) from practical built-in patterns like windowing and concurrent mapping to authoring your own custom …
Build Your First SaaS with MongoDB Ephemeral Clusters
Provision a MongoDB Atlas Ephemeral Cluster with one API call, then have an AI coding agent build a full-stack Spring Boot and React job …
World geography gotchas
Years ago, a colleague of mine told me about two pockets of foreign land surrounded by Switzerland: Campione d'Italia and Büsingen am …
Jakarta Faces, Java Web Framework, Stateless Edition: Marketplace AliFaces
A Fully Stateless Jakarta Faces Marketplace with Server-Side Rendering — No HttpSession, No Saved ViewState, No Sticky Sessions (see the poc …
Offline Crypto Address Validation in Java
Backend validation often starts with simple questions. Is the input empty? Does it have the expected shape? Can it be parsed? Does it belong …
Idempotent Write Paths: Keeping an Integration Pipeline Correct When Messages Repeat
A reconciliation that didn't add up Let me start with a real one. After a big sales promo, during reconciliation, finance said a batch of …
Idempotent Spring Boot: Safe REST with One Annotation
An idempotent Spring Boot starter that replays duplicate requests instead of re-executing them. One annotation, Redis or JDBC, atomic …