Merge branch '4.2.x'

docs/modules/ROOT/pages/spring-cloud-gateway-server-webmvc/filters/retry.adoc

@@ -9,6 +9,7 @@ The `Retry` filter supports the following parameters:
 * `methods`: The HTTP methods that should be retried, represented by using `org.springframework.http.HttpMethod`.
 * `series`: The series of status codes to be retried, represented by using `org.springframework.http.HttpStatus.Series`.
 * `exceptions`: A list of thrown exceptions that should be retried.
+* `cacheBody`: A flag to signal if the request body should be cached. If set to `true`, the `adaptCacheBody` filter must be used to send the cached body downstream.
 //* `backoff`: The configured exponential backoff for the retries.
 //Retries are performed after a backoff interval of `firstBackoff * (factor ^ n)`, where `n` is the iteration.
 //If `maxBackoff` is configured, the maximum backoff applied is limited to `maxBackoff`.
@@ -20,8 +21,11 @@ The following defaults are configured for `Retry` filter, if enabled:
 * `series`: 5XX series
 * `methods`: GET method
 * `exceptions`: `IOException`, `TimeoutException` and `RetryException`
+* `cacheBody`: `false`
 //* `backoff`: disabled
 
+WARNING: Setting `cacheBody` to `true` causes the gateway to read the whole body into memory. This should be used with caution.
+
 The following listing configures a Retry  filter:
 
 .application.yml
@@ -42,11 +46,14 @@ spring:
               retries: 3
               series: SERVER_ERROR
               methods: GET,POST
+              cacheBody: true
+          - name: AdaptCachedBody
 ----
 
 .GatewaySampleApplication.java
 [source,java]
 ----
+import static org.springframework.cloud.gateway.server.mvc.filter.FilterFunctions.adaptCachedBody;
 import static org.springframework.cloud.gateway.server.mvc.filter.RetryFilterFunctions.retry;
 import static org.springframework.cloud.gateway.server.mvc.handler.GatewayRouterFunctions.route;
 import static org.springframework.cloud.gateway.server.mvc.handler.HandlerFunctions.http;
@@ -59,7 +66,8 @@ class RouteConfiguration {
     public RouterFunction<ServerResponse> gatewayRouterFunctionsAddReqHeader() {
 		return route("add_request_parameter_route")
 			.route(host("*.retry.com"), http("https://example.org"))
-				.filter(retry(config -> config.setRetries(3).setSeries(Set.of(HttpStatus.Series.SERVER_ERROR)).setMethods(Set.of(HttpMethod.GET, HttpMethod.POST))))
+				.filter(retry(config -> config.setRetries(3).setSeries(Set.of(HttpStatus.Series.SERVER_ERROR)).setMethods(Set.of(HttpMethod.GET, HttpMethod.POST)).setCacheBody(true)))
+				.filter(adaptCachedBody())
 			.build();
     }
 }