Java DTO Guide: Fix Your API Design with One Simple Pattern

How to map Entities to DTOs in Spring Boot 3.
This tutorial shows how to use the Data Transfer Object (DTO) pattern to transfer data between application layers. We use Java records to reduce boilerplate code and the MapStruct library that simplifies Java bean mapping.

Works with Java 17+ and Spring Boot 3
Powered by Liberica JDK by BellSoft — a secure OpenJDK alternative

00:00 What Is a DTO in Spring Boot
00:22 Why You Shouldn’t Return Entities
01:00 Benefits of Using DTOs
01:24 Creating a DTO Class
01:48 Manual DTO Mapping
02:41 Updating Service & Controller
02:57 DTO Types Explained
04:12 MapStruct for Auto Mapping
13:34 Where to Use DTOs (REST, Kafka)
13:59 Wrap-Up: Clean Code with DTOs