Pass RSocketStrategies to MetadataExtractor

Simplify the creation of MetadataExtractor by not requiring
RSocketStrategies up front. The strategies are already configured in higher
level places like RSocketMessageHandler that invoke the MetadataExtractor.
The strategies are now passed in as an argument to the extract method.

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

@@ -31,7 +31,6 @@ import org.springframework.core.io.buffer.DataBuffer;
 import org.springframework.core.io.buffer.DataBufferFactory;
 import org.springframework.core.io.buffer.NettyDataBufferFactory;
 import org.springframework.lang.Nullable;
-import org.springframework.util.Assert;
 import org.springframework.util.MimeType;
 
 /**
@@ -48,17 +47,13 @@ import org.springframework.util.MimeType;
  */
 public class DefaultMetadataExtractor implements MetadataExtractor {
 
-	private final RSocketStrategies rsocketStrategies;
-
 	private final Map<String, EntryProcessor<?>> entryProcessors = new HashMap<>();
 
 
 	/**
 	 * Default constructor with {@link RSocketStrategies}.
 	 */
-	public DefaultMetadataExtractor(RSocketStrategies strategies) {
-		Assert.notNull(strategies, "RSocketStrategies is required");
-		this.rsocketStrategies = strategies;
+	public DefaultMetadataExtractor() {
 		// TODO: remove when rsocket-core API available
 		metadataToExtract(MetadataExtractor.ROUTING, String.class, ROUTE_KEY);
 	}
@@ -128,24 +123,26 @@ public class DefaultMetadataExtractor implements MetadataExtractor {
 
 
 	@Override
-	public Map<String, Object> extract(Payload payload, MimeType metadataMimeType) {
+	public Map<String, Object> extract(Payload payload, MimeType metadataMimeType, RSocketStrategies strategies) {
 		Map<String, Object> result = new HashMap<>();
 		if (metadataMimeType.equals(COMPOSITE_METADATA)) {
 			for (CompositeMetadata.Entry entry : new CompositeMetadata(payload.metadata(), false)) {
-				processEntry(entry.getContent(), entry.getMimeType(), result);
+				processEntry(entry.getContent(), entry.getMimeType(), result, strategies);
 			}
 		}
 		else {
-			processEntry(payload.metadata(), metadataMimeType.toString(), result);
+			processEntry(payload.metadata(), metadataMimeType.toString(), result, strategies);
 		}
 		return result;
 	}
 
-	private void processEntry(ByteBuf content, @Nullable String mimeType, Map<String, Object> result) {
+	private void processEntry(ByteBuf content,
+			@Nullable String mimeType, Map<String, Object> result, RSocketStrategies strategies) {
+
 		EntryProcessor<?> entryProcessor = this.entryProcessors.get(mimeType);
 		if (entryProcessor != null) {
 			content.retain();
-			entryProcessor.process(content, result);
+			entryProcessor.process(content, result, strategies);
 			return;
 		}
 		if (MetadataExtractor.ROUTING.toString().equals(mimeType)) {
@@ -166,8 +163,6 @@ public class DefaultMetadataExtractor implements MetadataExtractor {
 
 		private final BiConsumer<T, Map<String, Object>> accumulator;
 
-		private final Decoder<T> decoder;
-
 
 		public EntryProcessor(
 				MimeType mimeType, Class<T> targetType,
@@ -190,17 +185,17 @@ public class DefaultMetadataExtractor implements MetadataExtractor {
 			this.mimeType = mimeType;
 			this.targetType = targetType;
 			this.accumulator = accumulator;
-			this.decoder = rsocketStrategies.decoder(targetType, mimeType);
 		}
 
 
-		public void process(ByteBuf byteBuf, Map<String, Object> result) {
-			DataBufferFactory factory = rsocketStrategies.dataBufferFactory();
+		public void process(ByteBuf byteBuf, Map<String, Object> result, RSocketStrategies strategies) {
+			DataBufferFactory factory = strategies.dataBufferFactory();
 			DataBuffer buffer =  factory instanceof NettyDataBufferFactory ?
 					((NettyDataBufferFactory) factory).wrap(byteBuf) :
 					factory.wrap(byteBuf.nioBuffer());
 
-			T value = this.decoder.decode(buffer, this.targetType, this.mimeType, Collections.emptyMap());
+			Decoder<T> decoder = strategies.decoder(this.targetType, this.mimeType);
+			T value = decoder.decode(buffer, this.targetType, this.mimeType, Collections.emptyMap());
 			this.accumulator.accept(value, result);
 		}
 	}

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

@@ -58,8 +58,9 @@ public interface MetadataExtractor {
 	 * @param payload the payload whose metadata should be read
 	 * @param metadataMimeType the mime type of the metadata; this is what was
 	 * specified by the client at the start of the RSocket connection.
+	 * @param strategies for access to codecs and a DataBufferFactory
 	 * @return a map of 0 or more decoded metadata values with assigned names
 	 */
-	Map<String, Object> extract(Payload payload, MimeType metadataMimeType);
+	Map<String, Object> extract(Payload payload, MimeType metadataMimeType, RSocketStrategies strategies);
 
 }

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

@@ -31,7 +31,6 @@ import reactor.core.publisher.Mono;
 import reactor.core.publisher.MonoProcessor;
 
 import org.springframework.core.io.buffer.DataBuffer;
-import org.springframework.core.io.buffer.DataBufferFactory;
 import org.springframework.core.io.buffer.DataBufferUtils;
 import org.springframework.core.io.buffer.NettyDataBuffer;
 import org.springframework.lang.Nullable;
@@ -43,6 +42,7 @@ import org.springframework.messaging.handler.invocation.reactive.HandlerMethodRe
 import org.springframework.messaging.rsocket.MetadataExtractor;
 import org.springframework.messaging.rsocket.PayloadUtils;
 import org.springframework.messaging.rsocket.RSocketRequester;
+import org.springframework.messaging.rsocket.RSocketStrategies;
 import org.springframework.messaging.support.MessageBuilder;
 import org.springframework.messaging.support.MessageHeaderAccessor;
 import org.springframework.util.Assert;
@@ -73,12 +73,12 @@ class MessagingRSocket extends AbstractRSocket {
 
 	private final RSocketRequester requester;
 
-	private final DataBufferFactory bufferFactory;
+	private final RSocketStrategies strategies;
 
 
 	MessagingRSocket(MimeType dataMimeType, MimeType metadataMimeType, MetadataExtractor metadataExtractor,
 			RSocketRequester requester, ReactiveMessageHandler messageHandler,
-			RouteMatcher routeMatcher, DataBufferFactory bufferFactory) {
+			RouteMatcher routeMatcher, RSocketStrategies strategies) {
 
 		Assert.notNull(dataMimeType, "'dataMimeType' is required");
 		Assert.notNull(metadataMimeType, "'metadataMimeType' is required");
@@ -86,7 +86,7 @@ class MessagingRSocket extends AbstractRSocket {
 		Assert.notNull(requester, "'requester' is required");
 		Assert.notNull(messageHandler, "'messageHandler' is required");
 		Assert.notNull(routeMatcher, "'routeMatcher' is required");
-		Assert.notNull(bufferFactory, "'bufferFactory' is required");
+		Assert.notNull(strategies, "RSocketStrategies is required");
 
 		this.dataMimeType = dataMimeType;
 		this.metadataMimeType = metadataMimeType;
@@ -94,7 +94,7 @@ class MessagingRSocket extends AbstractRSocket {
 		this.requester = requester;
 		this.messageHandler = messageHandler;
 		this.routeMatcher = routeMatcher;
-		this.bufferFactory = bufferFactory;
+		this.strategies = strategies;
 	}
 
 
@@ -183,7 +183,7 @@ class MessagingRSocket extends AbstractRSocket {
 	}
 
 	private DataBuffer retainDataAndReleasePayload(Payload payload) {
-		return PayloadUtils.retainDataAndReleasePayload(payload, this.bufferFactory);
+		return PayloadUtils.retainDataAndReleasePayload(payload, this.strategies.dataBufferFactory());
 	}
 
 	private MessageHeaders createHeaders(Payload payload, FrameType frameType,
@@ -192,7 +192,9 @@ class MessagingRSocket extends AbstractRSocket {
 		MessageHeaderAccessor headers = new MessageHeaderAccessor();
 		headers.setLeaveMutable(true);
 
-		Map<String, Object> metadataValues = this.metadataExtractor.extract(payload, this.metadataMimeType);
+		Map<String, Object> metadataValues =
+				this.metadataExtractor.extract(payload, this.metadataMimeType, this.strategies);
+
 		metadataValues.putIfAbsent(MetadataExtractor.ROUTE_KEY, "");
 		for (Map.Entry<String, Object> entry : metadataValues.entrySet()) {
 			if (entry.getKey().equals(MetadataExtractor.ROUTE_KEY)) {
@@ -210,7 +212,8 @@ class MessagingRSocket extends AbstractRSocket {
 		if (replyMono != null) {
 			headers.setHeader(RSocketPayloadReturnValueHandler.RESPONSE_HEADER, replyMono);
 		}
-		headers.setHeader(HandlerMethodReturnValueHandler.DATA_BUFFER_FACTORY_HEADER, this.bufferFactory);
+		headers.setHeader(HandlerMethodReturnValueHandler.DATA_BUFFER_FACTORY_HEADER,
+				this.strategies.dataBufferFactory());
 
 		return headers.getMessageHeaders();
 	}

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

@@ -208,7 +208,7 @@ public class RSocketMessageHandler extends MessageMappingMessageHandler {
 					.build();
 		}
 		if (this.metadataExtractor == null) {
-			DefaultMetadataExtractor extractor = new DefaultMetadataExtractor(this.rsocketStrategies);
+			DefaultMetadataExtractor extractor = new DefaultMetadataExtractor();
 			extractor.metadataToExtract(MimeTypeUtils.TEXT_PLAIN, String.class, MetadataExtractor.ROUTE_KEY);
 			this.metadataExtractor = extractor;
 		}
@@ -318,7 +318,7 @@ public class RSocketMessageHandler extends MessageMappingMessageHandler {
 		Assert.notNull(this.metadataExtractor, () -> "No MetadataExtractor. Was afterPropertiesSet not called?");
 
 		return new MessagingRSocket(dataMimeType, metadataMimeType, this.metadataExtractor, requester,
-				this, getRouteMatcher(), strategies.dataBufferFactory());
+				this, getRouteMatcher(), strategies);
 	}
 
 }

spring-messaging/src/test/java/org/springframework/messaging/rsocket/DefaultMetadataExtractorTests.java

@@ -70,7 +70,7 @@ public class DefaultMetadataExtractorTests {
 		this.captor = ArgumentCaptor.forClass(Payload.class);
 		BDDMockito.when(this.rsocket.fireAndForget(captor.capture())).thenReturn(Mono.empty());
 
-		this.extractor = new DefaultMetadataExtractor(this.strategies);
+		this.extractor = new DefaultMetadataExtractor();
 	}
 
 	@After
@@ -91,7 +91,7 @@ public class DefaultMetadataExtractorTests {
 				.send().block();
 
 		Payload payload = this.captor.getValue();
-		Map<String, Object> result = this.extractor.extract(payload, COMPOSITE_METADATA);
+		Map<String, Object> result = this.extractor.extract(payload, COMPOSITE_METADATA, this.strategies);
 		payload.release();
 
 		assertThat(result).hasSize(1).containsEntry(ROUTE_KEY, "toA");
@@ -113,7 +113,7 @@ public class DefaultMetadataExtractorTests {
 				.block();
 
 		Payload payload = this.captor.getValue();
-		Map<String, Object> result = this.extractor.extract(payload, COMPOSITE_METADATA);
+		Map<String, Object> result = this.extractor.extract(payload, COMPOSITE_METADATA, this.strategies);
 		payload.release();
 
 		assertThat(result).hasSize(4)
@@ -128,7 +128,7 @@ public class DefaultMetadataExtractorTests {
 
 		requester(ROUTING).route("toA").data("data").send().block();
 		Payload payload = this.captor.getValue();
-		Map<String, Object> result = this.extractor.extract(payload, ROUTING);
+		Map<String, Object> result = this.extractor.extract(payload, ROUTING, this.strategies);
 		payload.release();
 
 		assertThat(result).hasSize(1).containsEntry(ROUTE_KEY, "toA");
@@ -141,7 +141,7 @@ public class DefaultMetadataExtractorTests {
 
 		requester(TEXT_PLAIN).route("toA").data("data").send().block();
 		Payload payload = this.captor.getValue();
-		Map<String, Object> result = this.extractor.extract(payload, TEXT_PLAIN);
+		Map<String, Object> result = this.extractor.extract(payload, TEXT_PLAIN, this.strategies);
 		payload.release();
 
 		assertThat(result).hasSize(1).containsEntry(ROUTE_KEY, "toA");
@@ -159,7 +159,7 @@ public class DefaultMetadataExtractorTests {
 
 		requester(TEXT_PLAIN).metadata("toA:text data", null).data("data").send().block();
 		Payload payload = this.captor.getValue();
-		Map<String, Object> result = this.extractor.extract(payload, TEXT_PLAIN);
+		Map<String, Object> result = this.extractor.extract(payload, TEXT_PLAIN, this.strategies);
 		payload.release();
 
 		assertThat(result).hasSize(2)