diff --git a/spring-web/src/main/java/org/springframework/web/cors/reactive/UrlBasedCorsConfigurationSource.java b/spring-web/src/main/java/org/springframework/web/cors/reactive/UrlBasedCorsConfigurationSource.java
index 2b97a1c7a8..6a454c64dd 100644
--- a/spring-web/src/main/java/org/springframework/web/cors/reactive/UrlBasedCorsConfigurationSource.java
+++ b/spring-web/src/main/java/org/springframework/web/cors/reactive/UrlBasedCorsConfigurationSource.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.
@@ -50,7 +50,7 @@ public class UrlBasedCorsConfigurationSource implements CorsConfigurationSource
 	 * @since 5.0.6
 	 */
 	public UrlBasedCorsConfigurationSource() {
-		this(new PathPatternParser());
+		this(PathPatternParser.defaultInstance);
 	}
 
 	/**
diff --git a/spring-web/src/main/java/org/springframework/web/util/pattern/PathPatternParser.java b/spring-web/src/main/java/org/springframework/web/util/pattern/PathPatternParser.java
index d083514f09..f7122a5318 100644
--- a/spring-web/src/main/java/org/springframework/web/util/pattern/PathPatternParser.java
+++ b/spring-web/src/main/java/org/springframework/web/util/pattern/PathPatternParser.java
@@ -122,4 +122,35 @@ public class PathPatternParser {
 		return new InternalPathPatternParser(this).parse(pathPattern);
 	}
 
+
+	/**
+	 * Shared, read-only instance of {@code PathPatternParser}. Uses default settings:
+	 * <ul>
+	 * <li>{@code matchOptionalTrailingSeparator=true}
+	 * <li>{@code caseSensitivetrue}
+	 * <li>{@code pathOptions=PathContainer.Options.HTTP_PATH}
+	 * </ul>
+	 */
+	public final static PathPatternParser defaultInstance = new PathPatternParser() {
+
+		@Override
+		public void setMatchOptionalTrailingSeparator(boolean matchOptionalTrailingSeparator) {
+			raiseError();
+		}
+
+		@Override
+		public void setCaseSensitive(boolean caseSensitive) {
+			raiseError();
+		}
+
+		@Override
+		public void setPathOptions(PathContainer.Options pathOptions) {
+			raiseError();
+		}
+
+		private void raiseError() {
+			throw new UnsupportedOperationException(
+					"This is a read-only, shared instance that cannot be modified");
+		}
+	};
 }
diff --git a/spring-webflux/src/main/java/org/springframework/web/reactive/function/server/PathResourceLookupFunction.java b/spring-webflux/src/main/java/org/springframework/web/reactive/function/server/PathResourceLookupFunction.java
index 0e2b719cc1..eb4109c223 100644
--- a/spring-webflux/src/main/java/org/springframework/web/reactive/function/server/PathResourceLookupFunction.java
+++ b/spring-webflux/src/main/java/org/springframework/web/reactive/function/server/PathResourceLookupFunction.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.
@@ -41,8 +41,6 @@ import org.springframework.web.util.pattern.PathPatternParser;
  */
 class PathResourceLookupFunction implements Function<ServerRequest, Mono<Resource>> {
 
-	private static final PathPatternParser PATTERN_PARSER = new PathPatternParser();
-
 	private final PathPattern pattern;
 
 	private final Resource location;
@@ -51,7 +49,7 @@ class PathResourceLookupFunction implements Function<ServerRequest, Mono<Resourc
 	public PathResourceLookupFunction(String pattern, Resource location) {
 		Assert.hasLength(pattern, "'pattern' must not be empty");
 		Assert.notNull(location, "'location' must not be null");
-		this.pattern = PATTERN_PARSER.parse(pattern);
+		this.pattern = PathPatternParser.defaultInstance.parse(pattern);
 		this.location = location;
 	}
 
diff --git a/spring-webflux/src/main/java/org/springframework/web/reactive/function/server/RequestPredicates.java b/spring-webflux/src/main/java/org/springframework/web/reactive/function/server/RequestPredicates.java
index 99386f7c8a..006c8fea46 100644
--- a/spring-webflux/src/main/java/org/springframework/web/reactive/function/server/RequestPredicates.java
+++ b/spring-webflux/src/main/java/org/springframework/web/reactive/function/server/RequestPredicates.java
@@ -72,9 +72,6 @@ public abstract class RequestPredicates {
 
 	private static final Log logger = LogFactory.getLog(RequestPredicates.class);
 
-	private static final PathPatternParser DEFAULT_PATTERN_PARSER = new PathPatternParser();
-
-
 	/**
 	 * Return a {@code RequestPredicate} that always matches.
 	 * @return a predicate that always matches
@@ -115,7 +112,7 @@ public abstract class RequestPredicates {
 		if (!pattern.isEmpty() && !pattern.startsWith("/")) {
 			pattern = "/" + pattern;
 		}
-		return pathPredicates(DEFAULT_PATTERN_PARSER).apply(pattern);
+		return pathPredicates(PathPatternParser.defaultInstance).apply(pattern);
 	}
 
 	/**
diff --git a/spring-webflux/src/main/java/org/springframework/web/reactive/resource/ResourceUrlProvider.java b/spring-webflux/src/main/java/org/springframework/web/reactive/resource/ResourceUrlProvider.java
index 1494f3870e..8bfcb0ccd7 100644
--- a/spring-webflux/src/main/java/org/springframework/web/reactive/resource/ResourceUrlProvider.java
+++ b/spring-webflux/src/main/java/org/springframework/web/reactive/resource/ResourceUrlProvider.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.
@@ -54,8 +54,6 @@ public class ResourceUrlProvider implements ApplicationListener<ContextRefreshed
 	private static final Log logger = LogFactory.getLog(ResourceUrlProvider.class);
 
 
-	private final PathPatternParser patternParser = new PathPatternParser();
-
 	private final Map<PathPattern, ResourceWebHandler> handlerMap = new LinkedHashMap<>();
 
 
@@ -78,7 +76,7 @@ public class ResourceUrlProvider implements ApplicationListener<ContextRefreshed
 		this.handlerMap.clear();
 		handlerMap.forEach((rawPattern, resourceWebHandler) -> {
 			rawPattern = prependLeadingSlash(rawPattern);
-			PathPattern pattern = this.patternParser.parse(rawPattern);
+			PathPattern pattern = PathPatternParser.defaultInstance.parse(rawPattern);
 			this.handlerMap.put(pattern, resourceWebHandler);
 		});
 	}
diff --git a/spring-webflux/src/main/java/org/springframework/web/reactive/result/condition/PatternsRequestCondition.java b/spring-webflux/src/main/java/org/springframework/web/reactive/result/condition/PatternsRequestCondition.java
index e0035a7248..0fe4803e66 100644
--- a/spring-webflux/src/main/java/org/springframework/web/reactive/result/condition/PatternsRequestCondition.java
+++ b/spring-webflux/src/main/java/org/springframework/web/reactive/result/condition/PatternsRequestCondition.java
@@ -43,7 +43,7 @@ import org.springframework.web.util.pattern.PathPatternParser;
 public final class PatternsRequestCondition extends AbstractRequestCondition<PatternsRequestCondition> {
 
 	private static final SortedSet<PathPattern> EMPTY_PATH_PATTERN =
-			new TreeSet<>(Collections.singleton(new PathPatternParser().parse("")));
+			new TreeSet<>(Collections.singleton(PathPatternParser.defaultInstance.parse("")));
 
 
 	private final SortedSet<PathPattern> patterns;
diff --git a/spring-webflux/src/main/java/org/springframework/web/reactive/result/method/RequestMappingInfo.java b/spring-webflux/src/main/java/org/springframework/web/reactive/result/method/RequestMappingInfo.java
index 344df2f3af..f6f2de2ad4 100644
--- a/spring-webflux/src/main/java/org/springframework/web/reactive/result/method/RequestMappingInfo.java
+++ b/spring-webflux/src/main/java/org/springframework/web/reactive/result/method/RequestMappingInfo.java
@@ -527,7 +527,7 @@ public final class RequestMappingInfo implements RequestCondition<RequestMapping
 		public RequestMappingInfo build() {
 
 			PathPatternParser parser = (this.options.getPatternParser() != null ?
-					this.options.getPatternParser() : new PathPatternParser());
+					this.options.getPatternParser() : PathPatternParser.defaultInstance);
 
 			RequestedContentTypeResolver contentTypeResolver = this.options.getContentTypeResolver();
 
diff --git a/spring-webmvc/src/main/java/org/springframework/web/servlet/function/PathResourceLookupFunction.java b/spring-webmvc/src/main/java/org/springframework/web/servlet/function/PathResourceLookupFunction.java
index 868bab7ae8..0dfb73d0ea 100644
--- a/spring-webmvc/src/main/java/org/springframework/web/servlet/function/PathResourceLookupFunction.java
+++ b/spring-webmvc/src/main/java/org/springframework/web/servlet/function/PathResourceLookupFunction.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 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.
@@ -40,8 +40,6 @@ import org.springframework.web.util.pattern.PathPatternParser;
  */
 class PathResourceLookupFunction implements Function<ServerRequest, Optional<Resource>> {
 
-	private static final PathPatternParser PATTERN_PARSER = new PathPatternParser();
-
 	private final PathPattern pattern;
 
 	private final Resource location;
@@ -50,7 +48,7 @@ class PathResourceLookupFunction implements Function<ServerRequest, Optional<Res
 	public PathResourceLookupFunction(String pattern, Resource location) {
 		Assert.hasLength(pattern, "'pattern' must not be empty");
 		Assert.notNull(location, "'location' must not be null");
-		this.pattern = PATTERN_PARSER.parse(pattern);
+		this.pattern = PathPatternParser.defaultInstance.parse(pattern);
 		this.location = location;
 	}
 
diff --git a/spring-webmvc/src/main/java/org/springframework/web/servlet/function/RequestPredicates.java b/spring-webmvc/src/main/java/org/springframework/web/servlet/function/RequestPredicates.java
index efc3fd9789..342074a816 100644
--- a/spring-webmvc/src/main/java/org/springframework/web/servlet/function/RequestPredicates.java
+++ b/spring-webmvc/src/main/java/org/springframework/web/servlet/function/RequestPredicates.java
@@ -71,9 +71,6 @@ public abstract class RequestPredicates {
 
 	private static final Log logger = LogFactory.getLog(RequestPredicates.class);
 
-	private static final PathPatternParser DEFAULT_PATTERN_PARSER = new PathPatternParser();
-
-
 	/**
 	 * Return a {@code RequestPredicate} that always matches.
 	 * @return a predicate that always matches
@@ -113,7 +110,7 @@ public abstract class RequestPredicates {
 		if (!pattern.isEmpty() && !pattern.startsWith("/")) {
 			pattern = "/" + pattern;
 		}
-		return pathPredicates(DEFAULT_PATTERN_PARSER).apply(pattern);
+		return pathPredicates(PathPatternParser.defaultInstance).apply(pattern);
 	}
 
 	/**