Configure RSocket server support in GraphQL

This commit adds the RSocket server auto-configuration for GraphQL.

See gh-30453

spring-boot-project/spring-boot-docs/src/main/java/org/springframework/boot/docs/web/graphql/transports/rsocket/RSocketGraphQlClientExample.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2012-2022 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.docs.web.graphql.transports.rsocket;
+
+import java.net.URI;
+import java.time.Duration;
+
+import reactor.core.publisher.Mono;
+
+import org.springframework.graphql.client.RSocketGraphQlClient;
+
+public class RSocketGraphQlClientExample {
+
+	public void rsocketOverTcp() {
+		// tag::tcp[]
+		RSocketGraphQlClient client = RSocketGraphQlClient.builder().tcp("example.spring.io", 8181).route("graphql")
+				.build();
+		Mono<Book> book = client.document("{ bookById(id: \"book-1\"){ id name pageCount author } }")
+				.retrieve("bookById").toEntity(Book.class);
+		// end::tcp[]
+		book.block(Duration.ofSeconds(5));
+	}
+
+	public void rsocketOverWebSocket() {
+		// tag::websocket[]
+		RSocketGraphQlClient client = RSocketGraphQlClient.builder()
+				.webSocket(URI.create("wss://example.spring.io/rsocket")).route("graphql").build();
+		Mono<Book> book = client.document("{ bookById(id: \"book-1\"){ id name pageCount author } }")
+				.retrieve("bookById").toEntity(Book.class);
+		// end::websocket[]
+		book.block(Duration.ofSeconds(5));
+	}
+
+	static class Book {
+
+	}
+
+}

spring-boot-project/spring-boot-docs/src/main/kotlin/org/springframework/boot/docs/web/graphql/transports/rsocket/RSocketGraphQlClientExample.kt

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2012-2022 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.docs.web.graphql.transports.rsocket
+
+import org.springframework.graphql.client.RSocketGraphQlClient
+import java.net.URI
+import java.time.Duration
+
+
+class RSocketGraphQlClientExample {
+
+	fun rsocketOverTcp() {
+		// tag::tcp[]
+		val client = RSocketGraphQlClient.builder()
+			.tcp("example.spring.io", 8181)
+			.route("graphql")
+			.build()
+		val book = client.document(
+			"""
+			{
+				bookById(id: "book-1"){
+					id
+					name
+					pageCount
+					author
+				}
+			}				
+			""")
+			.retrieve("bookById").toEntity(Book::class.java)
+		// end::tcp[]
+		book.block(Duration.ofSeconds(5))
+	}
+
+	fun rsocketOverWebSocket() {
+		// tag::websocket[]
+		val client = RSocketGraphQlClient.builder()
+			.webSocket(URI.create("wss://example.spring.io/rsocket"))
+			.route("graphql")
+			.build()
+		val book = client.document(
+			"""
+			{
+				bookById(id: "book-1"){
+					id
+					name
+					pageCount
+					author
+				}
+			}				
+			""")
+			.retrieve("bookById").toEntity(Book::class.java)
+		// end::websocket[]
+		book.block(Duration.ofSeconds(5))
+	}
+
+	internal class Book
+}