Polishing

Closes spring-projectsgh-30936

framework-docs/modules/ROOT/pages/rsocket.adoc

@@ -137,12 +137,12 @@ demonstrate its API and protocol features.
 
 The `spring-messaging` module contains the following:
 
-* xref:rsocket.adoc#rsocket-requester[RSocketRequester] -- fluent API to make requests through an `io.rsocket.RSocket`
-  with data and metadata encoding/decoding.
-* xref:rsocket.adoc#rsocket-interface[RSocket Interfaces] -- `@RSocketExchange` annotated
-interfaces for making requests.
+* xref:rsocket.adoc#rsocket-requester[RSocketRequester] -- fluent API to make requests
+through an `io.rsocket.RSocket` with data and metadata encoding/decoding.
 * xref:rsocket.adoc#rsocket-annot-responders[Annotated Responders] -- `@MessageMapping`
   and `@RSocketExchange` annotated handler methods for responding.
+* xref:rsocket.adoc#rsocket-interface[RSocket Interface] -- RSocket service declaration
+as Java interface with `@RSocketExchange` methods, for use as requester or responder.
 
 The `spring-web` module contains `Encoder` and `Decoder` implementations such as Jackson
 CBOR/JSON, and Protobuf that RSocket applications will likely need. It also contains the
@@ -864,26 +864,32 @@ interaction type(s):
 |===
 
 
+
 [[rsocket-annot-rsocketexchange]]
 === @RSocketExchange
 
-While `@MessageMapping` is only supported for responding,  `@RSocketExchange`
-can be used both to create an annotated responder
-and xref:rsocket.adoc#rsocket-interface[an RSocket Interface] that allows
-making requests.
+As an alternative to  `@MessageMapping`, you can also handle requests with
+`@RSocketExchange` methods. Such methods are declared on an
+xref:rsocket-interface[RSocket Interface] and can be used as a requester via
+`RSocketServiceProxyFactory` or as a responder.
 
-`@RSocketExchange` can be used as follows to create responder methods:
+For example, to handle requests as a responder:
 
 [tabs]
 ======
 Java::
 +
 [source,java,indent=0,subs="verbatim,quotes",role="primary"]
 ----
-	@Controller
-	public class RadarsController {
+	public interface RadarsService {
 
 		@RSocketExchange("locate.radars.within")
+		Flux<AirportLocation> radars(MapRequest request);
+	}
+
+	@Controller
+	public class RadarsController implements RadarsService {
+
 		public Flux<AirportLocation> radars(MapRequest request) {
 			// ...
 		}
@@ -894,28 +900,32 @@ Kotlin::
 +
 [source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
 ----
-@Controller
-class RadarsController {
+	interface RadarsService {
 
-	@RSocketExchange("locate.radars.within")
-	fun radars(request: MapRequest): Flow<AirportLocation> {
-		// ...
+		@RSocketExchange("locate.radars.within")
+		fun radars(request: MapRequest): Flow<AirportLocation>
+	}
+
+	@Controller
+	class RadarsController : RadarsService {
+
+		override fun radars(request: MapRequest): Flow<AirportLocation> {
+			// ...
+		}
 	}
-}
 ----
 ======
 
-`@RSocketExhange` supports a very similar method signature to `@MessageMapping`,
-however, since it needs to be suitable both for requester and responder use,
-there are slight differences. Notably, while `@MessageMapping` accepts
-a `String` array as its `value` parameter, only a single `String` can be passed
-as the `value` of `@RSocketExchange`.
+There some differences between `@RSocketExhange` and `@MessageMapping` since the
+former needs to remain suitable for requester and responder use. For example, while
+`@MessageMapping` can be declared to handle any number of routes and each route can
+be a pattern, `@RSocketExchange` must be declared with a single, concrete route. There are
+also small differences in the supported method parameters related to metadata, see
+xref:rsocket-annot-messagemapping[@MessageMapping] and
+xref:rsocket-interface[RSocket Interface] for a list of supported parameters.
 
-When it comes to possible return values and the way we establish supported
-RSocket interaction types, it works in the same way as with `@MessageMapping`.
-
-Similarly to `@MessageMapping`, `@RSocketExchange` can also be used at class
-level to specify a common prefix for all the method routes within the class.
+`@RSocketExchange` can be used at the type level to specify a common prefix for all routes
+for a given RSocket service interface.
 
 
 [[rsocket-annot-connectmapping]]
@@ -1052,12 +1062,13 @@ Kotlin::
 [[rsocket-interface]]
 == RSocket Interface
 
-The Spring Framework lets you define an RSocket service as a Java interface with annotated
-methods for RSocket exchanges. You can then generate a proxy that implements this interface
-and performs the exchanges. This helps to simplify RSocket remote access by wrapping the
-use of the underlying xref:rsocket.adoc#rsocket-requester[RSocketRequester].
+The Spring Framework lets you define an RSocket service as a Java interface with
+`@RSocketExchange` methods. You can pass such an interface to `RSocketServiceProxyFactory`
+to create a proxy which performs requests through an
+xref:rsocket.adoc#rsocket-requester[RSocketRequester]. You can also implement the
+interface as a responder that handles requests.
 
-One, declare an interface with `@RSocketExchange` methods:
+Start by creating the interface with `@RSocketExchange` methods:
 
 [source,java,indent=0,subs="verbatim,quotes"]
 ----
@@ -1071,7 +1082,7 @@ One, declare an interface with `@RSocketExchange` methods:
 	}
 ----
 
-Two, create a proxy that will perform the declared RSocket exchanges:
+Now you can create a proxy that performs requests when methods are called:
 
 [source,java,indent=0,subs="verbatim,quotes"]
 ----
@@ -1081,8 +1092,9 @@ Two, create a proxy that will perform the declared RSocket exchanges:
 	RepositoryService service = factory.createClient(RadarService.class);
 ----
 
-NOTE: Apart from RSocket interface services, `@RSocketExchange` can also
-be used to create xref:rsocket.adoc#rsocket-annot-rsocketexchange[annotated responders].
+You can also implement the interface to handle requests as a responder.
+See xref:rsocket.adoc#rsocket-annot-rsocketexchange[Annotated Responders].
+
 
 
 [[rsocket-interface-method-parameters]]

spring-messaging/src/main/java/org/springframework/messaging/rsocket/annotation/support/RSocketMessageHandler.java

@@ -60,10 +60,10 @@
 import org.springframework.util.StringUtils;
 
 /**
- * Extension of {@link MessageMappingMessageHandler} for handling RSocket
- * requests with {@link ConnectMapping @ConnectMapping},
- * {@link MessageMapping @MessageMapping}
- * and {@link RSocketExchange @RSocketExchange} methods.
+ * Extension of {@link MessageMappingMessageHandler} to handle RSocket
+ * requests with {@link MessageMapping @MessageMapping} and
+ * {@link ConnectMapping @ConnectMapping} methods, also supporting use of
+ * {@link RSocketExchange @RSocketExchange}.
  *
  * <p>For server scenarios this class can be declared as a bean in Spring
  * configuration and that would detect {@code @MessageMapping} methods in

spring-messaging/src/main/java/org/springframework/messaging/rsocket/service/RSocketExchange.java

@@ -25,8 +25,12 @@
 import org.springframework.aot.hint.annotation.Reflective;
 
 /**
- * Annotation to declare a method on an RSocket service interface as an RSocket
- * endpoint. The endpoint route is determined through the annotation attribute,
+ * Annotation to declare an RSocket endpoint on an RSocket service interface.
+ * Supported for use as an RSocket requester via
+ * {@link RSocketServiceProxyFactory}, and as a responder by implementing the
+ * interface to handle requests.
+ *
+ * <p>The endpoint route is determined through the annotation attribute,
  * and through the method arguments.
  *
  * <p>The annotation is supported at the type level to express a common route,

spring-messaging/src/main/java/org/springframework/messaging/rsocket/service/RSocketServiceProxyFactory.java

@@ -39,7 +39,7 @@
 import org.springframework.util.StringValueResolver;
 
 /**
- * Factory for creating a client proxy given an RSocket service interface with
+ * Factory to create a client proxy from an RSocket service interface with
  * {@link RSocketExchange @RSocketExchange} methods.
  *
  * <p>To create an instance, use static methods to obtain a