MapStruct Patterns for Jakarta EE

Best practices for using MapStruct with constructor-based mapping to achieve compile-time safety. When constructors change, mappings fail to compile — no runtime surprises.

Core Philosophy

Use constructors, not setters. This gives you compile-time errors when fields change.

Records naturally enforce this. For mutable entities, use the @Default annotation.

CDI Setup

@Mapper(componentModel = "cdi")  // CDI injection
public interface OrderMapper {
    OrderResponse toResponse(Order order);
}