RequestScope

RequestScope is a lifecycle used by dependency injection containers to bind the lifetime of certain objects to a single HTTP request. An instance defined as request-scoped is created when a request starts and is reused during that request; it is then released when the request ends.

Frameworks implement request scope in various ways. In Java, CDI provides @RequestScoped; in Spring, beans can be declared with @RequestScope; web frameworks in ASP.NET Core treat services with a scoped lifetime as per-request. The container manages creation, injection, and disposal of these instances as part of handling the HTTP request.

Common use cases include per-request caches, access to request parameters, user credentials verified for the duration of the request, and data transfer objects that do not need to be shared across requests. Request-scoped objects help maintain clean separation of concerns by avoiding cross-request data leakage and by enabling per-request customization.

Limitations: request-scoped objects are not suitable for data that must survive beyond a single request or be shared across concurrent requests. Asynchronous processing and complex threading can complicate lifecycle boundaries, so careful design is required to ensure proper disposal and to avoid unintended sharing. Resources held by a request-scoped object should be released promptly at the end of the request.

Related concepts include session scope, which persists across multiple requests from the same user, and application scope for data shared for the lifetime of the application.