Package org.springframework.web.reactive.function.server

Class RouterFunctions

java.lang.Object
org.springframework.web.reactive.function.server.RouterFunctions
public abstract class RouterFunctions extends Object
Central entry point to Spring's functional web framework. Exposes routing functionality, such as to create a RouterFunction using a discoverable builder-style API, to create a RouterFunction given a RequestPredicate and HandlerFunction, and to do further subrouting on an existing routing function.

Additionally, this class can transform a RouterFunction into an HttpHandler, which can be run in Servlet environments, Reactor, or Undertow.

Since:
5.0
Author:
Arjen Poutsma

  • Field Details

    • REQUEST_ATTRIBUTE

      public static final String REQUEST_ATTRIBUTE
      Name of the ServerWebExchange attribute that contains the ServerRequest.

    • URI_TEMPLATE_VARIABLES_ATTRIBUTE

      public static final String URI_TEMPLATE_VARIABLES_ATTRIBUTE
      Name of the ServerWebExchange attribute that contains the URI templates map, mapping variable names to values.

    • MATCHING_PATTERN_ATTRIBUTE

      public static final String MATCHING_PATTERN_ATTRIBUTE
      Name of the attribute that contains the matching pattern, as a PathPattern.

  • Constructor Details

    • RouterFunctions

      public RouterFunctions()

  • Method Details

    • route

      public static RouterFunctions.Builder route()
      Offers a discoverable way to create router functions through a builder-style interface.
      Returns:
      a router function builder
      Since:
      5.1

    • route

      public static <T extends ServerResponse> RouterFunction<T> route(RequestPredicate predicate, HandlerFunction<T> handlerFunction)
      Route to the given handler function if the given request predicate applies.

      For instance, the following example routes GET requests for "/user" to the listUsers method in userController: 

       RouterFunction<ServerResponse> route =
     RouterFunctions.route(RequestPredicates.GET("/user"), userController::listUsers);
      Type Parameters:
      T - the type of response returned by the handler function
      Parameters:
      predicate - the predicate to test
      handlerFunction - the handler function to route to if the predicate applies
      Returns:
      a router function that routes to handlerFunction if predicate evaluates to true
      See Also:

    • nest

      public static <T extends ServerResponse> RouterFunction<T> nest(RequestPredicate predicate, RouterFunction<T> routerFunction)
      Route to the given router function if the given request predicate applies. This method can be used to create nested routes, where a group of routes share a common path (prefix), header, or other request predicate.

      For instance, the following example first creates a composed route that resolves to listUsers for a GET, and createUser for a POST. This composed route then gets nested with a "/user" path predicate, so that GET requests for "/user" will list users, and POST request for "/user" will create a new user. 

       RouterFunction<ServerResponse> userRoutes =
   RouterFunctions.route(RequestPredicates.method(HttpMethod.GET), this::listUsers)
     .andRoute(RequestPredicates.method(HttpMethod.POST), this::createUser);
 RouterFunction<ServerResponse> nestedRoute =
   RouterFunctions.nest(RequestPredicates.path("/user"), userRoutes);
      Type Parameters:
      T - the type of response returned by the handler function
      Parameters:
      predicate - the predicate to test
      routerFunction - the nested router function to delegate to if the predicate applies
      Returns:
      a router function that routes to routerFunction if predicate evaluates to true
      See Also:

    • resources

      public static RouterFunction<ServerResponse> resources(String pattern, Resource location)
      Route requests that match the given pattern to resources relative to the given root location. For instance 
       Resource location = new FileSystemResource("public-resources/");
 RouterFunction<ServerResponse> resources = RouterFunctions.resources("/resources/**", location);
      Parameters:
      pattern - the pattern to match
      location - the location directory relative to which resources should be resolved
      Returns:
      a router function that routes to resources
      See Also:

    • resourceLookupFunction

      public static Function<ServerRequest,reactor.core.publisher.Mono<Resource>> resourceLookupFunction(String pattern, Resource location)
      Returns the resource lookup function used by resources(String, Resource). The returned function can be composed on, for instance to return a default resource when the lookup function does not match: 
       Mono<Resource> defaultResource = Mono.just(new ClassPathResource("index.html"));
 Function<ServerRequest, Mono<Resource>> lookupFunction =
   RouterFunctions.resourceLookupFunction("/resources/**", new FileSystemResource("public-resources/"))
     .andThen(resourceMono -> resourceMono.switchIfEmpty(defaultResource));
 RouterFunction<ServerResponse> resources = RouterFunctions.resources(lookupFunction);
      Parameters:
      pattern - the pattern to match
      location - the location directory relative to which resources should be resolved
      Returns:
      the default resource lookup function for the given parameters.

    • resources

      public static RouterFunction<ServerResponse> resources(Function<ServerRequest,reactor.core.publisher.Mono<Resource>> lookupFunction)
      Route to resources using the provided lookup function. If the lookup function provides a Resource for the given request, it will be it will be exposed using a HandlerFunction that handles GET, HEAD, and OPTIONS requests.
      Parameters:
      lookupFunction - the function to provide a Resource given the ServerRequest
      Returns:
      a router function that routes to resources

    • toHttpHandler

      public static HttpHandler toHttpHandler(RouterFunction<?> routerFunction)
      Convert the given router function into a HttpHandler. This conversion uses default strategies.

      The returned handler can be adapted to run in

      Note that HttpWebHandlerAdapter also implements WebHandler, allowing for additional filter and exception handler registration through WebHttpHandlerBuilder.

      Parameters:
      routerFunction - the router function to convert
      Returns:
      an http handler that handles HTTP request using the given router function

    • toHttpHandler

      public static HttpHandler toHttpHandler(RouterFunction<?> routerFunction, HandlerStrategies strategies)
      Convert the given router function into a HttpHandler, using the given strategies.

      The returned HttpHandler can be adapted to run in

      Parameters:
      routerFunction - the router function to convert
      strategies - the strategies to use
      Returns:
      an http handler that handles HTTP request using the given router function

    • toWebHandler

      public static WebHandler toWebHandler(RouterFunction<?> routerFunction)
      Convert the given router function into a WebHandler. This conversion uses default strategies.
      Parameters:
      routerFunction - the router function to convert
      Returns:
      a web handler that handles web request using the given router function

    • toWebHandler

      public static WebHandler toWebHandler(RouterFunction<?> routerFunction, HandlerStrategies strategies)
      Convert the given router function into a WebHandler, using the given strategies.
      Parameters:
      routerFunction - the router function to convert
      strategies - the strategies to use
      Returns:
      a web handler that handles web request using the given router function

    • changeParser

      public static <T extends ServerResponse> RouterFunction<T> changeParser(RouterFunction<T> routerFunction, PathPatternParser parser)
      Changes the PathPatternParser on the given router function. This method can be used to change the PathPatternParser properties from the defaults, for instance to change case sensitivity.
      Type Parameters:
      T - the type of response returned by the handler function
      Parameters:
      routerFunction - the router function to change the parser in
      parser - the parser to change to.
      Returns:
      the change router function