More accurate checks for presence of MediaType.ALL

Typically a straight up equals as well as Collections#contains
checks for MediaType.ALL is susceptible to the presence of
media type parameters.

This commits adds equalsTypeAndSubtype as well as an
isPresentIn(Collection<MimeType>) methods to MimeType to faciliate
with checks for MediaType.ALL.

Issue: SPR-17550

spring-core/src/main/java/org/springframework/util/MimeType.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.
@@ -19,6 +19,7 @@ package org.springframework.util;
 import java.io.Serializable;
 import java.nio.charset.Charset;
 import java.util.BitSet;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.Iterator;
@@ -383,6 +384,37 @@ public class MimeType implements Comparable<MimeType>, Serializable {
 		return false;
 	}
 
+	/**
+	 * Similar to {@link #equals(Object)} but based on the type and subtype
+	 * only, i.e. ignoring parameters.
+	 * @param other the other mime type to compare to
+	 * @return whether the two mime types have the same type and subtype
+	 * @since 5.1.4
+	 */
+	public boolean equalsTypeAndSubtype(@Nullable MimeType other) {
+		if (other == null) {
+			return false;
+		}
+		return this.type.equalsIgnoreCase(other.type) && this.subtype.equalsIgnoreCase(other.subtype);
+	}
+
+	/**
+	 * Unlike {@link Collection#contains(Object)} which relies on
+	 * {@link MimeType#equals(Object)}, this method only checks the type and the
+	 * subtype, but otherwise ignores parameters.
+	 * @param mimeTypes the list of mime types to perform the check against
+	 * @return whether the list contains the given mime type
+	 * @since 5.1.4
+	 */
+	public boolean isPresentIn(Collection<? extends MimeType> mimeTypes) {
+		for (MimeType mimeType : mimeTypes) {
+			if (mimeType.equalsTypeAndSubtype(this)) {
+				return true;
+			}
+		}
+		return false;
+	}
+
 
 	@Override
 	public boolean equals(Object other) {