# Package org.springframework.web.server

@NonNullApi @NonNullFields package org.springframework.web.server
Core interfaces and classes for Spring's generic, reactive web support. Builds on top of the `org.springframework.http.client.reactive` reactive HTTP adapter layer, providing additional constructs such as WebHandler, WebFilter, WebSession among others.

Related Packages
Package
Description
org.springframework.web
Common, generic interfaces that define minimal boundary points between Spring's web infrastructure and other framework modules.
org.springframework.web.server.adapter
Implementations to adapt to the underlying `org.springframework.http.client.reactive` reactive HTTP adapter and `HttpHandler`.
org.springframework.web.server.handler
Provides common WebHandler implementations and a `WebHandlerDecorator`.
org.springframework.web.server.i18n
Locale related support classes.
org.springframework.web.server.session
Auxiliary interfaces and implementation classes for `WebSession` support.
Class
Description
MethodNotAllowedException
Exception for errors that fit response status 405 (method not allowed).
MissingRequestValueException
`ServerWebInputException` subclass that indicates a missing request value such as a request header, cookie value, query parameter, etc.
NotAcceptableStatusException
Exception for errors that fit response status 406 (not acceptable).
PayloadTooLargeException
Exception for errors that fit response status 413 (payload too large) for use in Spring Web applications.
ResponseStatusException
Subclass of `ErrorResponseException` that accepts a "reason", and by default maps that to the `"detail"` of the `ProblemDetail`.
ServerErrorException
Exception for an `HttpStatus.INTERNAL_SERVER_ERROR` that exposes extra information about a controller method that failed, or a controller method argument that could not be resolved.
ServerWebExchange
Contract for an HTTP request-response interaction.
ServerWebExchange.Builder
Builder for mutating an existing `ServerWebExchange`.
ServerWebExchangeDecorator
A convenient base class for classes that need to wrap another `ServerWebExchange`.
ServerWebInputException
Exception for errors that fit response status 400 (bad request) for use in Spring Web applications.
UnsatisfiedRequestParameterException
`ServerWebInputException` subclass that indicates an unsatisfied parameter condition, as typically expressed using an `@RequestMapping` annotation at the `@Controller` type level.
UnsupportedMediaTypeStatusException
Exception for errors that fit response status 415 (unsupported media type).
WebExceptionHandler
Contract for handling exceptions during web server exchange processing.
WebFilter
Contract for interception-style, chained processing of Web requests that may be used to implement cross-cutting, application-agnostic requirements such as security, timeouts, and others.
WebFilterChain
Contract to allow a `WebFilter` to delegate to the next in the chain.
WebHandler
Contract to handle a web request.
WebSession
Main contract for using a server-side session that provides access to session attributes across HTTP requests.