Support reactive return type for RSocket

Closes gh-408

Author: sdeleuze

spring-graalvm-native-configuration/src/main/java/org/springframework/boot/autoconfigure/rsocket/RSocketMessagingHints.java

@@ -0,0 +1,16 @@
+package org.springframework.boot.autoconfigure.rsocket;
+
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import org.springframework.nativex.extension.NativeImageConfiguration;
+import org.springframework.nativex.extension.NativeImageHint;
+import org.springframework.nativex.extension.TypeInfo;
+import org.springframework.nativex.type.AccessBits;
+
+// TODO Should be possible to guess that automatically
+@NativeImageHint(trigger = RSocketMessagingAutoConfiguration.class, typeInfos= {
+		@TypeInfo(types = {Mono.class, Flux.class}, access = AccessBits.CLASS)
+})
+public class RSocketMessagingHints implements NativeImageConfiguration {
+}

spring-graalvm-native-configuration/src/main/resources/META-INF/services/org.springframework.nativex.extension.NativeImageConfiguration

@@ -45,6 +45,7 @@ org.springframework.boot.autoconfigure.jackson.JacksonHints
 org.springframework.boot.autoconfigure.jdbc.JdbcHints
 org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaHints
 org.springframework.boot.autoconfigure.r2dbc.R2dbcHints
+org.springframework.boot.autoconfigure.rsocket.RSocketMessagingHints
 org.springframework.boot.autoconfigure.security.servlet.SecurityHints
 org.springframework.boot.autoconfigure.session.SessionHints
 org.springframework.boot.autoconfigure.task.TaskHints

spring-graalvm-native-samples/rsocket/src/main/java/com/example/rsocket/RSocketController.java

@@ -1,5 +1,7 @@
 package com.example.rsocket;
 
+import reactor.core.publisher.Mono;
+
 import org.springframework.messaging.handler.annotation.MessageMapping;
 import org.springframework.stereotype.Controller;
 
@@ -10,4 +12,9 @@ public class RSocketController {
 	Message requestResponse(Message request) {
 		return new Message("SERVER", "RESPONSE");
 	}
+
+	@MessageMapping("mono-request-response")
+	Mono<Message> monoRequestResponse(Message request) {
+		return Mono.just(new Message("SERVER", "RESPONSE"));
+	}
 }

spring-graalvm-native-samples/rsocket/verify.sh

@@ -1,6 +1,8 @@
 #!/usr/bin/env bash
 if [[ `java -jar /opt/rsc.jar --debug --request --data "{\"origin\":\"Client\",\"interaction\":\"Request\"}" --route request-response tcp://localhost:7000 | grep "Frame => Stream ID: 1 Type: NEXT_COMPLETE Flags: 0b1100000 Length: 81"` ]]; then
-  exit 0
+  if [[ `java -jar /opt/rsc.jar --debug --request --data "{\"origin\":\"Client\",\"interaction\":\"Request\"}" --route mono-request-response tcp://localhost:7000 | grep "Frame => Stream ID: 1 Type: NEXT_COMPLETE Flags: 0b1100000 Length: 81"` ]]; then
+    exit 0
+  fi
 else
   exit 1
 fi