Inject LOOKUP_DESTINATION_HEADER if definition property is not used

spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/FunctionProperties.java

@@ -43,6 +43,12 @@ public class FunctionProperties {
 	 */
 	private String definition;
 
+
+	private String contentType = "application/json";
+
+
+	private String accept = "application/json";
+
 	/**
 	 * SpEL expression which should result in function definition (e.g., function name or composition instruction).
 	 * NOTE: SpEL evaluation context's root object is the input argument (e.g., Message).
@@ -64,4 +70,20 @@ public class FunctionProperties {
 	public void setRoutingExpression(String routingExpression) {
 		this.routingExpression = routingExpression;
 	}
+
+	public String getContentType() {
+		return contentType;
+	}
+
+	public void setContentType(String contentType) {
+		this.contentType = contentType;
+	}
+
+	public String getAccept() {
+		return accept;
+	}
+
+	public void setAccept(String accept) {
+		this.accept = accept;
+	}
 }

spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/catalog/SimpleFunctionRegistry.java

@@ -173,6 +173,7 @@ public class SimpleFunctionRegistry implements FunctionRegistry, FunctionInspect
 
 		if (this.functionAroundWrapper != null && function != null) {
 			return (T) new FunctionInvocationWrapper(function) {
+				@SuppressWarnings("rawtypes")
 				@Override
 				Object doApply(Object input, boolean consumer, Function<Message, Message> enricher) {
 					return functionAroundWrapper.apply(input, function);
@@ -805,7 +806,7 @@ public class SimpleFunctionRegistry implements FunctionRegistry, FunctionInspect
 				// this needs revisiting as the type is not always Class (think really complex types)
 				Type rawType = FunctionTypeUtils.unwrapActualTypeByIndex(type, 0);
 				if (logger.isDebugEnabled()) {
-					logger.debug("Raw type of value: " + value + "is " + rawType);
+					logger.debug("Raw type of value: " + value + " is " + rawType);
 				}
 
 				if (rawType instanceof ParameterizedType) {

spring-cloud-function-rsocket/src/main/java/org/springframework/cloud/function/rsocket/FunctionRSocketMessageHandler.java

@@ -16,6 +16,7 @@
 
 package org.springframework.cloud.function.rsocket;
 
+import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.util.Collections;
 import java.util.List;
@@ -29,6 +30,7 @@ import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
 import org.springframework.cloud.function.context.FunctionCatalog;
+import org.springframework.cloud.function.context.FunctionProperties;
 import org.springframework.cloud.function.context.catalog.SimpleFunctionRegistry.FunctionInvocationWrapper;
 import org.springframework.core.MethodParameter;
 import org.springframework.core.ParameterizedTypeReference;
@@ -39,8 +41,10 @@ import org.springframework.core.codec.ByteArrayEncoder;
 import org.springframework.core.codec.Decoder;
 import org.springframework.core.codec.Encoder;
 import org.springframework.core.io.buffer.DataBuffer;
+import org.springframework.http.server.PathContainer;
 import org.springframework.lang.Nullable;
 import org.springframework.messaging.Message;
+import org.springframework.messaging.MessageHeaders;
 import org.springframework.messaging.MessagingException;
 import org.springframework.messaging.handler.CompositeMessageCondition;
 import org.springframework.messaging.handler.DestinationPatternsMessageCondition;
@@ -53,8 +57,13 @@ import org.springframework.messaging.rsocket.annotation.support.RSocketFrameType
 import org.springframework.messaging.rsocket.annotation.support.RSocketMessageHandler;
 import org.springframework.messaging.rsocket.annotation.support.RSocketPayloadReturnValueHandler;
 import org.springframework.messaging.support.MessageBuilder;
+import org.springframework.util.AntPathMatcher;
 import org.springframework.util.MimeTypeUtils;
 import org.springframework.util.ReflectionUtils;
+import org.springframework.util.RouteMatcher;
+import org.springframework.util.SimpleRouteMatcher;
+import org.springframework.util.StringUtils;
+import org.springframework.web.util.pattern.PathPatternRouteMatcher;
 
 /**
  * An {@link RSocketMessageHandler} extension for Spring Cloud Function specifics.
@@ -68,6 +77,10 @@ class FunctionRSocketMessageHandler extends RSocketMessageHandler {
 
 	private final FunctionCatalog functionCatalog;
 
+	private final FunctionProperties functionProperties;
+
+	private final Field headersField;
+
 	private static final Method FUNCTION_APPLY_METHOD =
 		ReflectionUtils.findMethod(Function.class, "apply", (Class<?>[]) null);
 
@@ -78,9 +91,12 @@ class FunctionRSocketMessageHandler extends RSocketMessageHandler {
 			FrameType.REQUEST_STREAM,
 			FrameType.REQUEST_CHANNEL);
 
-	FunctionRSocketMessageHandler(FunctionCatalog functionCatalog) {
+	FunctionRSocketMessageHandler(FunctionCatalog functionCatalog, FunctionProperties functionProperties) {
 		setHandlerPredicate((clazz) -> false);
 		this.functionCatalog = functionCatalog;
+		this.functionProperties = functionProperties;
+		this.headersField = ReflectionUtils.findField(MessageHeaders.class, "headers");
+		this.headersField.setAccessible(true);
 	}
 
 
@@ -100,11 +116,21 @@ class FunctionRSocketMessageHandler extends RSocketMessageHandler {
 	 * Will check if there is a function handler registered for destination before proceeding.
 	 * This typically happens when user avoids using 'spring.cloud.function.definition' property.
 	 */
+	@SuppressWarnings("unchecked")
 	@Override
 	public Mono<Void> handleMessage(Message<?> message) throws MessagingException {
 
 		if (!FrameType.SETUP.equals(message.getHeaders().get("rsocketFrameType"))) {
 			String destination = this.getDestination(message).value();
+			if (!StringUtils.hasText(destination)) {
+				destination = this.functionProperties.getDefinition();
+				Map<String, Object> headersMap = (Map<String, Object>) ReflectionUtils
+						.getField(this.headersField, message.getHeaders());
+
+				PathPatternRouteMatcher matcher = new PathPatternRouteMatcher();
+
+				headersMap.put(DestinationPatternsMessageCondition.LOOKUP_DESTINATION_HEADER, matcher.parseRoute(destination));
+			}
 			Set<String> mappings = this.getDestinationLookup().keySet();
 			if (!mappings.contains(destination)) {
 				FunctionInvocationWrapper function = FunctionRSocketUtils

spring-cloud-function-rsocket/src/main/java/org/springframework/cloud/function/rsocket/RSocketAutoConfiguration.java

@@ -61,7 +61,7 @@ class RSocketAutoConfiguration implements ApplicationContextAware {
 		ObjectProvider<RSocketMessageHandlerCustomizer> customizers, FunctionCatalog functionCatalog,
 		FunctionProperties functionProperties) {
 
-		FunctionRSocketMessageHandler rsocketMessageHandler = new FunctionRSocketMessageHandler(functionCatalog);
+		FunctionRSocketMessageHandler rsocketMessageHandler = new FunctionRSocketMessageHandler(functionCatalog, functionProperties);
 		rsocketMessageHandler.setRSocketStrategies(rSocketStrategies);
 		customizers.orderedStream().forEach((customizer) -> customizer.customize(rsocketMessageHandler));
 		registerFunctionsWithRSocketHandler(rsocketMessageHandler, functionCatalog, functionProperties);
@@ -75,7 +75,6 @@ class RSocketAutoConfiguration implements ApplicationContextAware {
 			FunctionInvocationWrapper function = FunctionRSocketUtils
 					.registerFunctionForDestination(definition, functionCatalog, this.applicationContext);
 			rsocketMessageHandler.registerFunctionHandler(new RSocketListenerFunction(function), definition);
-			rsocketMessageHandler.registerFunctionHandler(new RSocketListenerFunction(function), "");
 		}
 	}