Support for setupPayload in RSocketRequester

Closes gh-23368

spring-messaging/src/main/java/org/springframework/messaging/rsocket/DefaultRSocketRequesterBuilder.java

@@ -19,9 +19,12 @@ package org.springframework.messaging.rsocket;
 import java.net.URI;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.function.Consumer;
 
+import io.rsocket.Payload;
 import io.rsocket.RSocketFactory;
 import io.rsocket.frame.decoder.PayloadDecoder;
 import io.rsocket.transport.ClientTransport;
@@ -29,11 +32,16 @@ import io.rsocket.transport.netty.client.TcpClientTransport;
 import io.rsocket.transport.netty.client.WebsocketClientTransport;
 import reactor.core.publisher.Mono;
 
+import org.springframework.core.ResolvableType;
 import org.springframework.core.codec.Decoder;
+import org.springframework.core.codec.Encoder;
 import org.springframework.core.codec.StringDecoder;
+import org.springframework.core.io.buffer.DataBuffer;
+import org.springframework.core.io.buffer.DataBufferUtils;
 import org.springframework.core.io.buffer.NettyDataBufferFactory;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.MimeType;
 
 /**
@@ -45,11 +53,26 @@ import org.springframework.util.MimeType;
  */
 final class DefaultRSocketRequesterBuilder implements RSocketRequester.Builder {
 
+	private static final Map<String, Object> HINTS = Collections.emptyMap();
+
+
 	@Nullable
 	private MimeType dataMimeType;
 
 	private MimeType metadataMimeType = MetadataExtractor.COMPOSITE_METADATA;
 
+	@Nullable
+	private Object setupData;
+
+	@Nullable
+	private String setupRoute;
+
+	@Nullable
+	private Object[] setupRouteVars;
+
+	@Nullable
+	private Map<Object, MimeType> setupMetadata;
+
 	@Nullable
 	private RSocketStrategies strategies;
 
@@ -71,6 +94,26 @@ final class DefaultRSocketRequesterBuilder implements RSocketRequester.Builder {
 		return this;
 	}
 
+	@Override
+	public RSocketRequester.Builder setupData(Object data) {
+		this.setupData = data;
+		return this;
+	}
+
+	@Override
+	public RSocketRequester.Builder setupRoute(String route, Object... routeVars) {
+		this.setupRoute = route;
+		this.setupRouteVars = routeVars;
+		return this;
+	}
+
+	@Override
+	public RSocketRequester.Builder setupMetadata(Object metadata, @Nullable MimeType mimeType) {
+		this.setupMetadata = (this.setupMetadata == null ? new LinkedHashMap<>(4) : this.setupMetadata);
+		this.setupMetadata.put(metadata, mimeType);
+		return this;
+	}
+
 	@Override
 	public RSocketRequester.Builder rsocketStrategies(@Nullable RSocketStrategies strategies) {
 		this.strategies = strategies;
@@ -120,12 +163,52 @@ final class DefaultRSocketRequesterBuilder implements RSocketRequester.Builder {
 		factory.dataMimeType(dataMimeType.toString());
 		factory.metadataMimeType(this.metadataMimeType.toString());
 
+		Payload setupPayload = getSetupPayload(dataMimeType, rsocketStrategies);
+		if (setupPayload != null) {
+			factory.setupPayload(setupPayload);
+		}
+
 		return factory.transport(transport)
 				.start()
 				.map(rsocket -> new DefaultRSocketRequester(
 						rsocket, dataMimeType, this.metadataMimeType, rsocketStrategies));
 	}
 
+	@Nullable
+	private Payload getSetupPayload(MimeType dataMimeType, RSocketStrategies strategies) {
+		DataBuffer metadata = null;
+		if (this.setupRoute != null || !CollectionUtils.isEmpty(this.setupMetadata)) {
+			metadata = new MetadataEncoder(this.metadataMimeType, strategies)
+					.metadataAndOrRoute(this.setupMetadata, this.setupRoute, this.setupRouteVars)
+					.encode();
+		}
+		DataBuffer data = null;
+		if (this.setupData != null) {
+			try {
+				ResolvableType type = ResolvableType.forClass(this.setupData.getClass());
+				Encoder<Object> encoder = strategies.encoder(type, dataMimeType);
+				Assert.notNull(encoder, () -> "No encoder for " + dataMimeType + ", " + type);
+				data = encoder.encodeValue(this.setupData, strategies.dataBufferFactory(), type, dataMimeType, HINTS);
+			}
+			catch (Throwable ex) {
+				if (metadata != null) {
+					DataBufferUtils.release(metadata);
+				}
+				throw ex;
+			}
+		}
+		if (metadata == null && data == null) {
+			return null;
+		}
+		metadata = metadata != null ? metadata : emptyBuffer(strategies);
+		data = data != null ? data : emptyBuffer(strategies);
+		return PayloadUtils.createPayload(metadata, data);
+	}
+
+	private DataBuffer emptyBuffer(RSocketStrategies strategies) {
+		return strategies.dataBufferFactory().wrap(new byte[0]);
+	}
+
 	private RSocketStrategies getRSocketStrategies() {
 		if (!this.strategiesConfigurers.isEmpty()) {
 			RSocketStrategies.Builder builder =

spring-messaging/src/main/java/org/springframework/messaging/rsocket/RSocketRequester.java

@@ -20,6 +20,7 @@ import java.net.URI;
 import java.util.function.Consumer;
 
 import io.rsocket.ConnectionSetupPayload;
+import io.rsocket.Payload;
 import io.rsocket.RSocket;
 import io.rsocket.transport.ClientTransport;
 import io.rsocket.transport.netty.client.TcpClientTransport;
@@ -139,6 +140,28 @@ public interface RSocketRequester {
 		 */
 		RSocketRequester.Builder metadataMimeType(MimeType mimeType);
 
+		/**
+		 * Set the data for the setup payload. The data will be encoded
+		 * according to the configured {@link #dataMimeType(MimeType)}.
+		 * <p>By default this is not set.
+		 */
+		RSocketRequester.Builder setupData(Object data);
+
+		/**
+		 * Set the route for the setup payload. The rules for formatting and
+		 * encoding the route are the same as those for a request route as
+		 * described in {@link #route(String, Object...)}.
+		 * <p>By default this is not set.
+		 */
+		RSocketRequester.Builder setupRoute(String route, Object... routeVars);
+
+		/**
+		 * Add metadata entry to the setup payload. Composite metadata must be
+		 * in use if this is called more than once or in addition to
+		 * {@link #setupRoute(String, Object...)}.
+		 */
+		RSocketRequester.Builder setupMetadata(Object value, @Nullable MimeType mimeType);
+
 		/**
 		 * Provide {@link RSocketStrategies} to use.
 		 * <p>By default this is based on default settings of
@@ -157,12 +180,20 @@ public interface RSocketRequester {
 
 		/**
 		 * Callback to configure the {@code ClientRSocketFactory} directly.
-		 * <p>Note that the data and metadata mime types cannot be set directly
-		 * on the {@code ClientRSocketFactory}. Use shortcuts on this builder
-		 * {@link #dataMimeType(MimeType)} and {@link #metadataMimeType(MimeType)}
-		 * instead.
-		 * <p>To configure client side responding, see
+		 * <ul>
+		 * <li>The data and metadata mime types cannot be set directly
+		 * on the {@code ClientRSocketFactory} and will be overridden. Use the
+		 * shortcuts {@link #dataMimeType(MimeType)} and
+		 * {@link #metadataMimeType(MimeType)} on this builder instead.
+		 * <li>The frame decoder also cannot be set directly and instead is set
+		 * to match the configured {@code DataBufferFactory}.
+		 * <li>For the
+		 * {@link io.rsocket.RSocketFactory.ClientRSocketFactory#setupPayload(Payload)
+		 * setupPayload}, consider using methods on this builder to specify the
+		 * route, other metadata, and data as Object values to be encoded.
+		 * <li>To configure client side responding, see
 		 * {@link RSocketMessageHandler#clientResponder(RSocketStrategies, Object...)}.
+		 * </ul>
 		 */
 		RSocketRequester.Builder rsocketFactory(ClientRSocketFactoryConfigurer configurer);
 

spring-messaging/src/main/java/org/springframework/messaging/rsocket/RSocketStrategies.java

@@ -188,7 +188,8 @@ public interface RSocketStrategies {
 		 * Configure a {@link MetadataExtractor} to extract the route along with
 		 * other metadata. This option is applicable to client or server
 		 * responders.
-		 * <p>By default this is {@link DefaultMetadataExtractor} extracting a
+		 * <p>By default this is {@link DefaultMetadataExtractor} created with
+		 * the {@link #decoder(Decoder[]) configured} decoders and extracting a
 		 * route from {@code "message/x.rsocket.routing.v0"} metadata.
 		 */
 		Builder metadataExtractor(@Nullable MetadataExtractor metadataExtractor);