Polish adapt to and from Mono conversion

See gh-10112

spring-boot/src/main/java/org/springframework/boot/endpoint/web/jersey/JerseyEndpointResourceFactory.java

@@ -106,12 +106,13 @@ public class JerseyEndpointResourceFactory {
 		private static final List<Function<Object, Object>> bodyConverters;
 
 		static {
-			bodyConverters = new ArrayList<>();
+			List<Function<Object, Object>> converters = new ArrayList<>();
-			bodyConverters.add(new ResourceBodyConverter());
+			converters.add(new ResourceBodyConverter());
 			if (ClassUtils.isPresent("reactor.core.publisher.Mono",
 					EndpointInvokingInflector.class.getClassLoader())) {
-				bodyConverters.add(new MonoBodyConverter());
+				converters.add(new MonoBodyConverter());
 			}
+			bodyConverters = Collections.unmodifiableList(converters);
 		}
 
 		private final OperationInvoker operationInvoker;
@@ -193,11 +194,8 @@ public class JerseyEndpointResourceFactory {
 		}
 
 		private Object convertIfNecessary(Object body) throws IOException {
-			if (body instanceof org.springframework.core.io.Resource) {
+			for (Function<Object, Object> converter : bodyConverters) {
-				return ((org.springframework.core.io.Resource) body).getInputStream();
+				body = converter.apply(body);
-			}
-			if (body instanceof Mono) {
-				return ((Mono<?>) body).block();
 			}
 			return body;
 		}

spring-boot/src/main/java/org/springframework/boot/endpoint/web/reactive/WebEndpointReactiveHandlerMapping.java

@@ -24,6 +24,7 @@ import java.util.Map;
 
 import org.reactivestreams.Publisher;
 import reactor.core.publisher.Mono;
+import reactor.core.publisher.MonoSink;
 import reactor.core.scheduler.Schedulers;
 
 import org.springframework.beans.factory.InitializingBean;
@@ -212,9 +213,8 @@ public class WebEndpointReactiveHandlerMapping extends RequestMappingInfoHandler
 			return Mono.from(result).map(this::toResponseEntity)
 					.onErrorReturn(ParameterMappingException.class,
 							new ResponseEntity<>(HttpStatus.BAD_REQUEST))
-					.defaultIfEmpty(
+					.defaultIfEmpty(new ResponseEntity<>(httpMethod == HttpMethod.GET
-							new ResponseEntity<>(httpMethod == HttpMethod.GET
+							? HttpStatus.NOT_FOUND : HttpStatus.NO_CONTENT));
-									? HttpStatus.NOT_FOUND : HttpStatus.NO_CONTENT));
 		}
 
 		private ResponseEntity<Object> toResponseEntity(Object response) {
@@ -277,18 +277,20 @@ public class WebEndpointReactiveHandlerMapping extends RequestMappingInfoHandler
 		@Override
 		public Object invoke(Map<String, Object> arguments) {
 			return Mono.create((sink) -> {
-				Schedulers.elastic().schedule(() -> {
+				Schedulers.elastic().schedule(() -> invoke(arguments, sink));
-					try {
-						Object result = this.delegate.invoke(arguments);
-						sink.success(result);
-					}
-					catch (Exception ex) {
-						sink.error(ex);
-					}
-				});
 			});
 		}
 
+		private void invoke(Map<String, Object> arguments, MonoSink<Object> sink) {
+			try {
+				Object result = this.delegate.invoke(arguments);
+				sink.success(result);
+			}
+			catch (Exception ex) {
+				sink.error(ex);
+			}
+		}
+
 	}
 
 }