diff --git a/spring-core/src/main/java/org/springframework/core/OrderComparator.java b/spring-core/src/main/java/org/springframework/core/OrderComparator.java
index f38f392367..a478d6e085 100644
--- a/spring-core/src/main/java/org/springframework/core/OrderComparator.java
+++ b/spring-core/src/main/java/org/springframework/core/OrderComparator.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -27,6 +27,10 @@ import org.springframework.util.ObjectUtils;
  * {@link Comparator} implementation for {@link Ordered} objects, sorting
  * by order value ascending, respectively by priority descending.
  *
+ * <h3>{@code PriorityOrdered} Objects</h3>
+ * <p>{@link PriorityOrdered} objects will be sorted with higher priority than
+ * <em>plain</em> {@code Ordered} objects.
+ *
  * <h3>Same Order Objects</h3>
  * <p>Objects that have the same order value will be sorted with arbitrary
  * ordering with respect to other objects with the same order value.
@@ -41,6 +45,7 @@ import org.springframework.util.ObjectUtils;
  * @author Sam Brannen
  * @since 07.04.2003
  * @see Ordered
+ * @see PriorityOrdered
  * @see org.springframework.core.annotation.AnnotationAwareOrderComparator
  * @see java.util.List#sort(java.util.Comparator)
  * @see java.util.Arrays#sort(Object[], java.util.Comparator)
@@ -96,8 +101,7 @@ public class OrderComparator implements Comparator<Object> {
 			Object orderSource = sourceProvider.getOrderSource(obj);
 			if (orderSource != null) {
 				if (orderSource.getClass().isArray()) {
-					Object[] sources = ObjectUtils.toObjectArray(orderSource);
-					for (Object source : sources) {
+					for (Object source : ObjectUtils.toObjectArray(orderSource)) {
 						order = findOrder(source);
 						if (order != null) {
 							break;
diff --git a/spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/support/AbstractNamedValueMethodArgumentResolver.java b/spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/support/AbstractNamedValueMethodArgumentResolver.java
index 486148260a..b86164a136 100644
--- a/spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/support/AbstractNamedValueMethodArgumentResolver.java
+++ b/spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/support/AbstractNamedValueMethodArgumentResolver.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -149,8 +149,9 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 		if (info.name.isEmpty()) {
 			name = parameter.getParameterName();
 			if (name == null) {
-				throw new IllegalArgumentException("Name for argument type [" + parameter.getParameterType().getName() +
-						"] not available, and parameter name information not found in class file either.");
+				throw new IllegalArgumentException(
+						"Name for argument of type [" + parameter.getNestedParameterType().getName() +
+						"] not specified, and parameter name information not found in class file either.");
 			}
 		}
 		String defaultValue = (ValueConstants.DEFAULT_NONE.equals(info.defaultValue) ? null : info.defaultValue);
diff --git a/spring-messaging/src/main/java/org/springframework/messaging/simp/stomp/DefaultStompSession.java b/spring-messaging/src/main/java/org/springframework/messaging/simp/stomp/DefaultStompSession.java
index 7b782d6a0e..487b24f42b 100644
--- a/spring-messaging/src/main/java/org/springframework/messaging/simp/stomp/DefaultStompSession.java
+++ b/spring-messaging/src/main/java/org/springframework/messaging/simp/stomp/DefaultStompSession.java
@@ -111,7 +111,7 @@ public class DefaultStompSession implements ConnectionHandlingStompSession {
 	private final Map<String, ReceiptHandler> receiptHandlers = new ConcurrentHashMap<>(4);
 
 	/* Whether the client is willfully closing the connection */
-	private volatile boolean closing = false;
+	private volatile boolean closing;
 
 
 	/**
@@ -256,7 +256,7 @@ public class DefaultStompSession implements ConnectionHandlingStompSession {
 	private Message<byte[]> createMessage(StompHeaderAccessor accessor, @Nullable Object payload) {
 		accessor.updateSimpMessageHeadersFromStompHeaders();
 		Message<byte[]> message;
-		if (isEmpty(payload)) {
+		if (StringUtils.isEmpty(payload) || (payload instanceof byte[] && ((byte[]) payload).length == 0)) {
 			message = MessageBuilder.createMessage(EMPTY_PAYLOAD, accessor.getMessageHeaders());
 		}
 		else {
@@ -271,10 +271,6 @@ public class DefaultStompSession implements ConnectionHandlingStompSession {
 		return message;
 	}
 
-	private boolean isEmpty(@Nullable Object payload) {
-		return (StringUtils.isEmpty(payload) || (payload instanceof byte[] && ((byte[]) payload).length == 0));
-	}
-
 	private void execute(Message<byte[]> message) {
 		if (logger.isTraceEnabled()) {
 			StompHeaderAccessor accessor = MessageHeaderAccessor.getAccessor(message, StompHeaderAccessor.class);
diff --git a/spring-web/src/main/java/org/springframework/web/method/annotation/AbstractNamedValueMethodArgumentResolver.java b/spring-web/src/main/java/org/springframework/web/method/annotation/AbstractNamedValueMethodArgumentResolver.java
index cc247ef510..55ea38da9e 100644
--- a/spring-web/src/main/java/org/springframework/web/method/annotation/AbstractNamedValueMethodArgumentResolver.java
+++ b/spring-web/src/main/java/org/springframework/web/method/annotation/AbstractNamedValueMethodArgumentResolver.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -131,7 +131,6 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 			catch (TypeMismatchException ex) {
 				throw new MethodArgumentTypeMismatchException(arg, ex.getRequiredType(),
 						namedValueInfo.name, parameter, ex.getCause());
-
 			}
 		}
 
@@ -170,8 +169,8 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 			name = parameter.getParameterName();
 			if (name == null) {
 				throw new IllegalArgumentException(
-						"Name for argument type [" + parameter.getNestedParameterType().getName() +
-						"] not available, and parameter name information not found in class file either.");
+						"Name for argument of type [" + parameter.getNestedParameterType().getName() +
+						"] not specified, and parameter name information not found in class file either.");
 			}
 		}
 		String defaultValue = (ValueConstants.DEFAULT_NONE.equals(info.defaultValue) ? null : info.defaultValue);
@@ -184,12 +183,12 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 	 */
 	@Nullable
 	private Object resolveStringValue(String value) {
-		if (this.configurableBeanFactory == null) {
+		if (this.configurableBeanFactory == null || this.expressionContext == null) {
 			return value;
 		}
 		String placeholdersResolved = this.configurableBeanFactory.resolveEmbeddedValue(value);
 		BeanExpressionResolver exprResolver = this.configurableBeanFactory.getBeanExpressionResolver();
-		if (exprResolver == null || this.expressionContext == null) {
+		if (exprResolver == null) {
 			return value;
 		}
 		return exprResolver.evaluate(placeholdersResolved, this.expressionContext);
diff --git a/spring-web/src/main/java/org/springframework/web/multipart/support/MissingServletRequestPartException.java b/spring-web/src/main/java/org/springframework/web/multipart/support/MissingServletRequestPartException.java
index 62e1f1dee6..414405d803 100644
--- a/spring-web/src/main/java/org/springframework/web/multipart/support/MissingServletRequestPartException.java
+++ b/spring-web/src/main/java/org/springframework/web/multipart/support/MissingServletRequestPartException.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -26,7 +26,7 @@ import org.springframework.web.multipart.MultipartResolver;
  *
  * <p>This may be because the request is not a multipart/form-data request,
  * because the part is not present in the request, or because the web
- * application is not configured correctly for processing  multipart requests,
+ * application is not configured correctly for processing multipart requests,
  * e.g. no {@link MultipartResolver}.
  *
  * @author Rossen Stoyanchev
@@ -35,17 +35,24 @@ import org.springframework.web.multipart.MultipartResolver;
 @SuppressWarnings("serial")
 public class MissingServletRequestPartException extends ServletException {
 
-	private final String partName;
+	private final String requestPartName;
 
 
-	public MissingServletRequestPartException(String partName) {
-		super("Required request part '" + partName + "' is not present");
-		this.partName = partName;
+	/**
+	 * Constructor for MissingServletRequestPartException.
+	 * @param requestPartName the name of the missing part of the multipart request
+	 */
+	public MissingServletRequestPartException(String requestPartName) {
+		super("Required request part '" + requestPartName + "' is not present");
+		this.requestPartName = requestPartName;
 	}
 
 
+	/**
+	 * Return the name of the offending part of the multipart request.
+	 */
 	public String getRequestPartName() {
-		return this.partName;
+		return this.requestPartName;
 	}
 
 }
diff --git a/spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/AbstractNamedValueArgumentResolver.java b/spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/AbstractNamedValueArgumentResolver.java
index c7cd8e3af8..9c0fb6021e 100644
--- a/spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/AbstractNamedValueArgumentResolver.java
+++ b/spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/AbstractNamedValueArgumentResolver.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -144,9 +144,9 @@ public abstract class AbstractNamedValueArgumentResolver extends HandlerMethodAr
 		if (info.name.isEmpty()) {
 			name = parameter.getParameterName();
 			if (name == null) {
-				String type = parameter.getNestedParameterType().getName();
-				throw new IllegalArgumentException("Name for argument type [" + type + "] not " +
-						"available, and parameter name information not found in class file either.");
+				throw new IllegalArgumentException(
+						"Name for argument of type [" + parameter.getNestedParameterType().getName() +
+						"] not specified, and parameter name information not found in class file either.");
 			}
 		}
 		String defaultValue = (ValueConstants.DEFAULT_NONE.equals(info.defaultValue) ? null : info.defaultValue);