JPA – Part 5 (DTO–TABLE)
1. Hibernate DDL Auto Configuration spring.jpa.hibernate.ddl-auto This property tells Hibernate how to handle DB schema. Value Create Update Delete Use case none ❌ ❌ ❌ Does nothing – Best…
JPA – Second Level Cache (L2 Cache)
JPA – Second Level Cache (L2 Cache) What problem does L2 Cache solve? From your previous First Level Cache: Every HTTP request creates a new EntityManager Each EntityManager…
Spring Boot – JPA First Level Cache (Persistence Context)
Spring Boot – JPA First Level Cache (Persistence Context) Core Concept (from PDF) First Level Cache = Persistence Context It is enabled by default in JPA/Hibernate. It is scoped…
Spring Boot JPA – Architecture (Part 2)
Spring Boot JPA – Architecture (Part 2) JPA is not magic. Behind the scenes, Spring Boot creates and wires several components that work together whenever your API hits the…
Spring Boot JPA – Part 1
Spring Boot JPA – Part 1 From JDBC Pain to ORM Power When we start working with databases in Java, the first thing we usually touch is JDBC. It…
Spring Boot – Exception Handling (Deep Notes)
Spring Boot – Exception Handling (Deep Notes) 1. Core Classes in Spring Exception Handling From the class diagram on page 1: HandlerExceptionResolver (interface) | HandlerExceptionResolverComposite | AbstractHandlerExceptionResolver | ---------------------------------------------------…
Spring Boot – ResponseEntity & HTTP Response Codes
Spring Boot – ResponseEntity & HTTP Response Codes (Deep Notes + Extra Concepts + Interview Q&A) 1. What is an HTTP Response? According to page 1, every HTTP response…
Spring Boot – ResponseEntity & HTTP Response Codes
Spring Boot – ResponseEntity & HTTP Response Codes 1. What is an HTTP Response? From page 1, a response has 3 parts: Status Code – e.g. 200, 404, 500 Headers…
Spring Boot – HATEOAS (Notes + Extra)
Spring Boot – HATEOAS (Notes + Extra) 1. What is HATEOAS? HATEOAS = Hypermedia As The Engine Of Application State It means: The API response itself tells the client…
Spring Boot: Filters vs Interceptors (Notes + Extra)
Spring Boot: Filters vs Interceptors (Notes + Extra) 1. Basic Difference Filter Interceptor Intercepts HTTP Request & Response before reaching the servlet Intercepts before reaching the Controller Part of…