#java

Learn Circuit Breaker Pattern in Spring Boot with Resilience4j - from operating principles, detailed configuration, practical examples to best practices. A complete guide to help you build resilient microservices systems, prevent cascading failures and automatically recover when services encounter problems.

Duy TranDecember 23, 202535 min

How to search on encrypted data? This article presents 3 practical approaches and implementations with Spring Boot + PostgreSQL to protect 100,000+ patient records.

Duy TranDecember 15, 202515 min

A hands-on series on building a complete Microservices system with Quarkus 3.x — the "Supersonic Subatomic" Java framework designed specifically for Cloud Native and Kubernetes. Using PostgreSQL as main database, Keycloak for Authentication & Authorization (OIDC), Apache Kafka for Event-Driven Communication, gRPC for high-performance inter-service. From creating your first project with Dev Services, building a REST API with Panache, to deploying production on Kubernetes with GraalVM Native Image. Includes Fault Tolerance, OpenTelemetry Observability, Contract Testing, CI/CD Pipeline and Production Readiness Checklist. Actual project: E-Commerce Platform system includes 5 microservices.

Step-by-step instructions for building a medical information system (HIS/EMR/LIS) with Microservices architecture using Quarkus, PostgreSQL and Keycloak. Compliant with HIPAA, HL7 FHIR, Zero Trust security standards. From architectural design, building services, decentralization, data encryption, audit logging to production deployment on Kubernetes. Each article has practical code, ready to be applied to hospitals and medical facilities.

Comprehensive course on the HL7 FHIR (Fast Healthcare Interoperability Resources) data standard in healthcare — from theoretical foundation to practical implementation. Covers HL7 history (v2, v3, CDA), FHIR R5 architecture, Core Resources (Patient, Observation, Encounter, Medication, DiagnosticReport), RESTful API (CRUD, Search, Bundle, Transaction), Data Types, Terminologies (ICD-10, SNOMED CT, LOINC), Profiles & Extensions, SMART on FHIR, FHIR Subscriptions, building FHIR Server with FHIR HAPI (Java/Spring Boot), integration with EMR/HIS, Security & Privacy systems (HIPAA, GDPR), and practical applications in Vietnam (Circular 54/2017/TT-BYT, VNEID, Social Insurance). Updated to FHIR R5 (v5.0.0), the latest official version from HL7 International.

Comprehensive course on Spring Boot 4.x from basic to advanced, helping you build professional backend applications with REST APIs, Spring Data JPA, Spring Security, JWT, OAuth2, microservices, testing, Docker and deployment in production environments. Update Spring Boot 4.0 with Spring Framework 7, Virtual Threads, GraalVM Native Image.