response-layout

Use a layout query parameter (?layout=summary/detailed/full) resolved by a LayoutResolver, then route through a LayoutRegistry to a LayoutStrategy that maps the entity to the matching DTO. The controller passes the HttpServletRequest to a LayoutHandler and returns the resulting DTO.

Add a new value to the LayoutType enum, create the new DTO class, and implement a new LayoutStrategy annotated with @Component. Spring injects it into the registry automatically, so the handler, resolver, and existing strategies require zero changes.

Use layout strategies when endpoints return substantially different field sets per client type or when layouts involve expensive computed fields. For differences of only one or two fields, Jackson's @JsonInclude or @JsonView annotations are simpler.

The LayoutType.fromString method defaults to DETAILED when the parameter is blank or unparseable. If no strategy matches a resolved type, the LayoutHandler logs a warning and falls back to the DETAILED strategy, throwing an exception only if DETAILED itself is missing.

Yes. The resolver is a separate component, so you can swap the query-parameter implementation for one that inspects the Accept header, such as matching application/vnd.api.summary+json, without touching the handler, registry, or strategies.