diff --git a/spring-core/src/main/java/org/springframework/core/ReactiveAdapterRegistry.java b/spring-core/src/main/java/org/springframework/core/ReactiveAdapterRegistry.java
index 4afa633d3a..48213cd343 100644
--- a/spring-core/src/main/java/org/springframework/core/ReactiveAdapterRegistry.java
+++ b/spring-core/src/main/java/org/springframework/core/ReactiveAdapterRegistry.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -141,15 +141,17 @@ public class ReactiveAdapterRegistry {
 		if (clazz == null) {
 			return null;
 		}
-
-		return this.adapters.stream()
-				.filter(adapter -> adapter.getReactiveType() == clazz)
-				.findFirst()
-				.orElseGet(() ->
-						this.adapters.stream()
-								.filter(adapter -> adapter.getReactiveType().isAssignableFrom(clazz))
-								.findFirst()
-								.orElse(null));
+		for(ReactiveAdapter adapter : this.adapters) {
+			if (adapter.getReactiveType() == clazz) {
+				return adapter;
+			}
+		}
+		for(ReactiveAdapter adapter : this.adapters) {
+			if (adapter.getReactiveType().isAssignableFrom(clazz)) {
+				return adapter;
+			}
+		}
+		return null;
 	}
 
 
diff --git a/spring-core/src/main/java/org/springframework/core/codec/AbstractEncoder.java b/spring-core/src/main/java/org/springframework/core/codec/AbstractEncoder.java
index b1d220616f..242a7bccc3 100644
--- a/spring-core/src/main/java/org/springframework/core/codec/AbstractEncoder.java
+++ b/spring-core/src/main/java/org/springframework/core/codec/AbstractEncoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -74,7 +74,12 @@ public abstract class AbstractEncoder<T> implements Encoder<T> {
 		if (mimeType == null) {
 			return true;
 		}
-		return this.encodableMimeTypes.stream().anyMatch(candidate -> candidate.isCompatibleWith(mimeType));
+		for(MimeType candidate : this.encodableMimeTypes) {
+			if (candidate.isCompatibleWith(mimeType)) {
+				return true;
+			}
+		}
+		return false;
 	}
 
 }
diff --git a/spring-core/src/main/java/org/springframework/core/log/CompositeLog.java b/spring-core/src/main/java/org/springframework/core/log/CompositeLog.java
index 9d46d28a95..cbdfcf9d6c 100644
--- a/spring-core/src/main/java/org/springframework/core/log/CompositeLog.java
+++ b/spring-core/src/main/java/org/springframework/core/log/CompositeLog.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -63,7 +63,12 @@ final class CompositeLog implements Log {
 	}
 
 	private static Log initLogger(List<Log> loggers, Predicate<Log> predicate) {
-		return loggers.stream().filter(predicate).findFirst().orElse(NO_OP_LOG);
+		for (Log logger : loggers) {
+			if (predicate.test(logger)) {
+				return logger;
+			}
+		}
+		return NO_OP_LOG;
 	}
 
 
diff --git a/spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/AbstractMessageWriterResultHandler.java b/spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/AbstractMessageWriterResultHandler.java
index 188cb838e9..ff0b26f0d1 100644
--- a/spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/AbstractMessageWriterResultHandler.java
+++ b/spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/AbstractMessageWriterResultHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -16,8 +16,8 @@
 
 package org.springframework.web.reactive.result.method.annotation;
 
+import java.util.ArrayList;
 import java.util.List;
-import java.util.stream.Collectors;
 
 import org.reactivestreams.Publisher;
 import reactor.core.publisher.Mono;
@@ -137,7 +137,8 @@ public abstract class AbstractMessageWriterResultHandler extends HandlerResultHa
 
 		ServerHttpRequest request = exchange.getRequest();
 		ServerHttpResponse response = exchange.getResponse();
-		MediaType bestMediaType = selectMediaType(exchange, () -> getMediaTypesFor(elementType));
+		List<MediaType> writableMediaTypes = getMediaTypesFor(elementType);
+		MediaType bestMediaType = selectMediaType(exchange, () -> writableMediaTypes);
 		if (bestMediaType != null) {
 			String logPrefix = exchange.getLogPrefix();
 			if (logger.isDebugEnabled()) {
@@ -152,12 +153,12 @@ public abstract class AbstractMessageWriterResultHandler extends HandlerResultHa
 			}
 		}
 		else {
-			if (getMediaTypesFor(elementType).isEmpty()) {
+			if (writableMediaTypes.isEmpty()) {
 				return Mono.error(new IllegalStateException("No writer for : " + elementType));
 			}
 		}
 
-		return Mono.error(new NotAcceptableStatusException(getMediaTypesFor(elementType)));
+		return Mono.error(new NotAcceptableStatusException(writableMediaTypes));
 	}
 
 	private ResolvableType getElementType(ReactiveAdapter adapter, ResolvableType genericType) {
@@ -173,10 +174,13 @@ public abstract class AbstractMessageWriterResultHandler extends HandlerResultHa
 	}
 
 	private List<MediaType> getMediaTypesFor(ResolvableType elementType) {
-		return getMessageWriters().stream()
-				.filter(converter -> converter.canWrite(elementType, null))
-				.flatMap(converter -> converter.getWritableMediaTypes().stream())
-				.collect(Collectors.toList());
+		List<MediaType> writableMediaTypes = new ArrayList<>();
+		for (HttpMessageWriter<?> converter : getMessageWriters()) {
+			if (converter.canWrite(elementType, null)) {
+				writableMediaTypes.addAll(converter.getWritableMediaTypes());
+			}
+		}
+		return writableMediaTypes;
 	}
 
 }