• Data Transfer Objects (DTOs): Structures for packing data during application or process information exchange. Have only state; business objects have both state and behavior. Considered the "apparel" for the domain when interacting with the exterior. Java records are useful for data-oriented structures, removing boilerplate code.
• In REST APIs: Service implementers expose details to clients. In a weather forecast service example, DTOs are structured to pack only needed information as client applications don't use all details. Java records offer a newer, simpler option for DTO design and implementation.
• Proof of Concept: Using Indian Wells, California (where the BNP Paribas Open takes place) as the place of interest. Weather.gov REST API is used to get weather forecasts. Focus is on data received and client DTO design.
• Implementation Details: Uses Java 21, Spring Boot 3.4.4, RestClient, and Maven 3.9.9. Two-step process to retrieve forecast: call GET for points and then for gridpoints. Responses are verbose. DTOs are modeled using Java records for the two API responses. The temperatureUnit is renamed for better naming in the DTOs. A ForecastService class is implemented to retrieve and process the forecasts. A unit test is used to display the forecasts for Indian Wells.
• Conclusion: Java records are useful for organizing DTOs due to their succinctness and data-oriented nature. Save programmers time by handling boilerplate code.
• Resources: National Weather Service API, article source code on GitHub, and a picture from this year's official collection.