Showing Posts From
Framework
Jason Yang · 02 Jun, 2026
Optimistic locking in Spring Boot and JPA: how it works and how to make it production-ready with retries, backoff, jitter, observability, and fallback.
System Design
Jason Yang · 13 May, 2026
The Liskov Substitution Principle in Java: why the classic Rectangle/Square example violates LSP, and how smaller interfaces or composition fix the design.
System Design
Jason Yang · 13 May, 2026
Apply the Open-Closed Principle in Java with the Strategy Pattern — add new behavior without editing core logic, shown with a payment-processing example.
System Design
Jason Yang · 13 May, 2026
DIP vs DI in Java: they work together but differ — DIP keeps logic depending on abstractions, DI supplies dependencies from outside. Explained with examples.
System Design
Jason Yang · 12 May, 2026
SOLID principles in Java explained with simple examples — SRP, OCP, LSP, ISP, and DIP, each with backend-focused code. The full series index starts here.
System Design
Jason Yang · 12 May, 2026
Dependency Inversion Principle in Java, explained with notification, payment gateway, Spring Boot, and testing examples.
System Design
Jason Yang · 12 May, 2026
The Interface Segregation Principle in Java: why one fat interface forces empty methods and UnsupportedOperationException, and how small focused interfaces fix it — with phone, printer, and backend examples.
System Design
Jason Yang · 12 May, 2026
The Liskov Substitution Principle in Java: why a subclass that breaks its parent's contract violates LSP, shown with bird, Flyable, and discount policy examples.
System Design
Jason Yang · 12 May, 2026
The Open-Closed Principle in Java: add new behavior without touching stable code, shown with payment methods, interfaces, and Spring Boot style examples.
System Design
Jason Yang · 12 May, 2026
The Single Responsibility Principle in Java: what 'one reason to change' actually means in practice, with backend service and Spring Boot style examples.
Programming Language
Jason Yang · 22 Mar, 2026
When to use HashSet, LinkedHashSet, or TreeSet in Java: their differences explained simply, and how they map to Python's set, dict, and sorted().
Framework
Jason Yang · 26 Jan, 2026
MapStruct is a compile-time mapping tool for Spring projects that reduces boilerplate, improves safety, and makes DTO mapping cleaner and more testable.
Programming Language
Jason Yang · 01 Jan, 2026
Lombok's @Builder ignores your field defaults — use @Builder.Default or final to keep them. Here's why it happens and how to fix it.
Programming Language
Jason Yang · 02 Dec, 2025
Add a gRPC endpoint to a Spring Boot order-service: define .proto files, generate stubs, implement the RPC logic, and expose a new CreateOrder API.
Programming Language
Jason Yang · 29 Nov, 2025
Exception logging in Java done right: catch errors in the correct layer, log them once, and keep clear context — practical patterns for real systems.
Programming Language
Jason Yang · 29 Nov, 2025
Design effective custom exceptions in Java: structure them well, separate business and system errors, and integrate cleanly with Spring Boot error handling.
Programming Language
Jason Yang · 28 Nov, 2025
Why real Spring Boot developers prefer unchecked exceptions over the textbook rules — modern exception-handling patterns for clean, maintainable service code.
Programming Language
Jason Yang · 27 Nov, 2025
Understand Java's Throwable hierarchy — Error vs Exception, checked vs unchecked, and RuntimeException — to write safer error handling in production apps.
Framework
Jason Yang · 22 Nov, 2025
Spring Boot 'required a bean of type String' error? It often hits when switching to constructor injection. How to correctly inject @Value into constructors.
Framework
Jason Yang · 22 Nov, 2025
Integrate Swagger (OpenAPI) into Spring Boot with springdoc: secure your endpoints with JWT auth and auto-generate the API docs.
Programming Language
Jason Yang · 14 Nov, 2025
Checked exceptions are enforced by the Java compiler; unchecked ones aren't — here's the difference, with the class hierarchy, code examples, and when each applies.
