Merge branch '5.2.x'

spring-test/src/main/java/org/springframework/mock/http/server/reactive/MockServerHttpRequest.java

@@ -232,6 +232,8 @@ public final class MockServerHttpRequest extends AbstractServerHttpRequest {
 	 * @return the created builder
 	 */
 	public static BodyBuilder method(HttpMethod method, String urlTemplate, Object... vars) {
+		Assert.notNull(method, "HttpMethod is required. If testing a custom HTTP method, " +
+				"please use the variant that accepts a String based HTTP method.");
 		URI url = UriComponentsBuilder.fromUriString(urlTemplate).buildAndExpand(vars).encode().toUri();
 		return new DefaultBodyBuilder(method, url);
 	}

spring-web/src/main/java/org/springframework/http/server/reactive/WriteResultPublisher.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.
@@ -182,6 +182,9 @@ class WriteResultPublisher implements Publisher<Void> {
 			@Override
 			void publishError(WriteResultPublisher publisher, Throwable ex) {
 				publisher.errorBeforeSubscribed = ex;
+				if(State.SUBSCRIBED.equals(publisher.state.get())) {
+					publisher.state.get().publishError(publisher, ex);
+				}
 			}
 		},
 
@@ -200,6 +203,9 @@ class WriteResultPublisher implements Publisher<Void> {
 			@Override
 			void publishError(WriteResultPublisher publisher, Throwable ex) {
 				publisher.errorBeforeSubscribed = ex;
+				if(State.SUBSCRIBED.equals(publisher.state.get())) {
+					publisher.state.get().publishError(publisher, ex);
+				}
 			}
 		},
 

spring-web/src/testFixtures/java/org/springframework/web/testfixture/http/server/reactive/MockServerHttpRequest.java

@@ -232,6 +232,8 @@ public final class MockServerHttpRequest extends AbstractServerHttpRequest {
 	 * @return the created builder
 	 */
 	public static BodyBuilder method(HttpMethod method, String urlTemplate, Object... vars) {
+		Assert.notNull(method, "HttpMethod is required. If testing a custom HTTP method, " +
+				"please use the variant that accepts a String based HTTP method.");
 		URI url = UriComponentsBuilder.fromUriString(urlTemplate).buildAndExpand(vars).encode().toUri();
 		return new DefaultBodyBuilder(method, url);
 	}

spring-webflux/src/main/java/org/springframework/web/reactive/result/condition/ConsumesRequestCondition.java

@@ -29,6 +29,7 @@ import org.springframework.http.MediaType;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.lang.Nullable;
 import org.springframework.util.CollectionUtils;
+import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.cors.reactive.CorsUtils;
@@ -75,39 +76,39 @@ public final class ConsumesRequestCondition extends AbstractRequestCondition<Con
 	 * @param headers as described in {@link RequestMapping#headers()}
 	 */
 	public ConsumesRequestCondition(String[] consumes, String[] headers) {
-		this.expressions = new ArrayList<>(parseExpressions(consumes, headers));
+		this.expressions = parseExpressions(consumes, headers);
 		if (this.expressions.size() > 1) {
 			Collections.sort(this.expressions);
 		}
 	}
 
-	/**
+	private static List<ConsumeMediaTypeExpression> parseExpressions(String[] consumes, String[] headers) {
-	 * Private constructor for internal when creating matching conditions.
+		Set<ConsumeMediaTypeExpression> result = null;
-	 * Note the expressions List is neither sorted nor deep copied.
+		if (!ObjectUtils.isEmpty(headers)) {
-	 */
-	private ConsumesRequestCondition(List<ConsumeMediaTypeExpression> expressions) {
-		this.expressions = expressions;
-	}
-
-
-	private static Set<ConsumeMediaTypeExpression> parseExpressions(String[] consumes, String[] headers) {
-		Set<ConsumeMediaTypeExpression> result = new LinkedHashSet<>();
-		if (headers != null) {
 			for (String header : headers) {
 				HeadersRequestCondition.HeaderExpression expr = new HeadersRequestCondition.HeaderExpression(header);
 				if ("Content-Type".equalsIgnoreCase(expr.name)) {
+					result = (result != null ? result : new LinkedHashSet<>());
 					for (MediaType mediaType : MediaType.parseMediaTypes(expr.value)) {
 						result.add(new ConsumeMediaTypeExpression(mediaType, expr.isNegated));
 					}
 				}
 			}
 		}
-		if (consumes != null) {
+		if (!ObjectUtils.isEmpty(consumes)) {
+			result = (result != null ? result : new LinkedHashSet<>());
 			for (String consume : consumes) {
 				result.add(new ConsumeMediaTypeExpression(consume));
 			}
 		}
-		return result;
+		return (result != null ? new ArrayList<>(result) : Collections.emptyList());
+	}
+
+	/**
+	 * Private constructor for internal when creating matching conditions.
+	 */
+	private ConsumesRequestCondition(List<ConsumeMediaTypeExpression> expressions) {
+		this.expressions = expressions;
 	}
 
 

spring-webflux/src/main/java/org/springframework/web/reactive/result/condition/HeadersRequestCondition.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.
@@ -17,10 +17,12 @@
 package org.springframework.web.reactive.result.condition;
 
 import java.util.Collection;
+import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.Set;
 
 import org.springframework.lang.Nullable;
+import org.springframework.util.ObjectUtils;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.cors.reactive.CorsUtils;
 import org.springframework.web.server.ServerWebExchange;
@@ -52,28 +54,29 @@ public final class HeadersRequestCondition extends AbstractRequestCondition<Head
 	 * if 0, the condition will match to every request
 	 */
 	public HeadersRequestCondition(String... headers) {
-		this(parseExpressions(headers));
+		this.expressions = parseExpressions(headers);
 	}
 
-	private HeadersRequestCondition(Set<HeaderExpression> conditions) {
-		this.expressions = conditions;
-	}
-
-
 	private static Set<HeaderExpression> parseExpressions(String... headers) {
-		Set<HeaderExpression> expressions = new LinkedHashSet<>();
+		Set<HeaderExpression> result = null;
-		if (headers != null) {
+		if (!ObjectUtils.isEmpty(headers)) {
 			for (String header : headers) {
 				HeaderExpression expr = new HeaderExpression(header);
 				if ("Accept".equalsIgnoreCase(expr.name) || "Content-Type".equalsIgnoreCase(expr.name)) {
 					continue;
 				}
-				expressions.add(expr);
+				result = (result != null ? result : new LinkedHashSet<>(headers.length));
+				result.add(expr);
 			}
 		}
-		return expressions;
+		return (result != null ? result : Collections.emptySet());
 	}
 
+	private HeadersRequestCondition(Set<HeaderExpression> conditions) {
+		this.expressions = conditions;
+	}
+
+
 	/**
 	 * Return the contained request header expressions.
 	 */
@@ -97,6 +100,15 @@ public final class HeadersRequestCondition extends AbstractRequestCondition<Head
 	 */
 	@Override
 	public HeadersRequestCondition combine(HeadersRequestCondition other) {
+		if (isEmpty() && other.isEmpty()) {
+			return this;
+		}
+		else if (other.isEmpty()) {
+			return this;
+		}
+		else if (isEmpty()) {
+			return other;
+		}
 		Set<HeaderExpression> set = new LinkedHashSet<>(this.expressions);
 		set.addAll(other.expressions);
 		return new HeadersRequestCondition(set);

spring-webflux/src/main/java/org/springframework/web/reactive/result/condition/ParamsRequestCondition.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.
@@ -21,6 +21,7 @@ import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.Set;
 
+import org.springframework.util.ObjectUtils;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.server.ServerWebExchange;
 
@@ -42,22 +43,22 @@ public final class ParamsRequestCondition extends AbstractRequestCondition<Param
 	 * 	if 0, the condition will match to every request.
 	 */
 	public ParamsRequestCondition(String... params) {
-		this(parseExpressions(params));
+		this.expressions = parseExpressions(params);
 	}
 
-	private ParamsRequestCondition(Collection<ParamExpression> conditions) {
+	private static Set<ParamExpression> parseExpressions(String... params) {
-		this.expressions = Collections.unmodifiableSet(new LinkedHashSet<>(conditions));
+		if (ObjectUtils.isEmpty(params)) {
+			return Collections.emptySet();
+		}
+		Set<ParamExpression> result = new LinkedHashSet<>(params.length);
+		for (String param : params) {
+			result.add(new ParamExpression(param));
+		}
+		return result;
 	}
 
-
+	private ParamsRequestCondition(Set<ParamExpression> conditions) {
-	private static Collection<ParamExpression> parseExpressions(String... params) {
+		this.expressions = conditions;
-		Set<ParamExpression> expressions = new LinkedHashSet<>();
-		if (params != null) {
-			for (String param : params) {
-				expressions.add(new ParamExpression(param));
-			}
-		}
-		return expressions;
 	}
 
 
@@ -84,6 +85,15 @@ public final class ParamsRequestCondition extends AbstractRequestCondition<Param
 	 */
 	@Override
 	public ParamsRequestCondition combine(ParamsRequestCondition other) {
+		if (isEmpty() && other.isEmpty()) {
+			return this;
+		}
+		else if (other.isEmpty()) {
+			return this;
+		}
+		else if (isEmpty()) {
+			return other;
+		}
 		Set<ParamExpression> set = new LinkedHashSet<>(this.expressions);
 		set.addAll(other.expressions);
 		return new ParamsRequestCondition(set);

spring-webflux/src/main/java/org/springframework/web/reactive/result/condition/PatternsRequestCondition.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.
@@ -27,6 +27,7 @@ import java.util.TreeSet;
 
 import org.springframework.http.server.PathContainer;
 import org.springframework.lang.Nullable;
+import org.springframework.util.ObjectUtils;
 import org.springframework.web.server.ServerWebExchange;
 import org.springframework.web.util.pattern.PathPattern;
 import org.springframework.web.util.pattern.PathPatternParser;
@@ -41,7 +42,7 @@ import org.springframework.web.util.pattern.PathPatternParser;
  */
 public final class PatternsRequestCondition extends AbstractRequestCondition<PatternsRequestCondition> {
 
-	private static final SortedSet<PathPattern> EMPTY_PATTERNS =
+	private static final SortedSet<PathPattern> EMPTY_PATH_PATTERN =
 			new TreeSet<>(Collections.singleton(new PathPatternParser().parse("")));
 
 
@@ -53,21 +54,21 @@ public final class PatternsRequestCondition extends AbstractRequestCondition<Pat
 	 * @param patterns 0 or more URL patterns; if 0 the condition will match to every request.
 	 */
 	public PatternsRequestCondition(PathPattern... patterns) {
-		this(Arrays.asList(patterns));
+		this(ObjectUtils.isEmpty(patterns) ? Collections.emptyList() : Arrays.asList(patterns));
 	}
 
 	/**
 	 * Creates a new instance with the given URL patterns.
 	 */
 	public PatternsRequestCondition(List<PathPattern> patterns) {
-		this(patterns.isEmpty() ? EMPTY_PATTERNS : new TreeSet<>(patterns));
+		this.patterns = (patterns.isEmpty() ? EMPTY_PATH_PATTERN : new TreeSet<>(patterns));
 	}
 
-
 	private PatternsRequestCondition(SortedSet<PathPattern> patterns) {
 		this.patterns = patterns;
 	}
 
+
 	public Set<PathPattern> getPatterns() {
 		return this.patterns;
 	}
@@ -94,25 +95,28 @@ public final class PatternsRequestCondition extends AbstractRequestCondition<Pat
 	 */
 	@Override
 	public PatternsRequestCondition combine(PatternsRequestCondition other) {
-		SortedSet<PathPattern> combined;
+		if (isEmptyPathPattern() && other.isEmptyPathPattern()) {
-		if (!this.patterns.isEmpty() && !other.patterns.isEmpty()) {
+			return this;
-			combined = new TreeSet<>();
+		}
+		else if (other.isEmptyPathPattern()) {
+			return this;
+		}
+		else if (isEmptyPathPattern()) {
+			return other;
+		}
+		else {
+			SortedSet<PathPattern> combined = new TreeSet<>();
 			for (PathPattern pattern1 : this.patterns) {
 				for (PathPattern pattern2 : other.patterns) {
 					combined.add(pattern1.combine(pattern2));
 				}
 			}
+			return new PatternsRequestCondition(combined);
 		}
-		else if (!this.patterns.isEmpty()) {
+	}
-			combined = this.patterns;
+
-		}
+	private boolean isEmptyPathPattern() {
-		else if (!other.patterns.isEmpty()) {
+		return this.patterns == EMPTY_PATH_PATTERN;
-			combined = other.patterns;
-		}
-		else {
-			combined = EMPTY_PATTERNS;
-		}
-		return new PatternsRequestCondition(combined);
 	}
 
 	/**
@@ -126,31 +130,21 @@ public final class PatternsRequestCondition extends AbstractRequestCondition<Pat
 	@Override
 	@Nullable
 	public PatternsRequestCondition getMatchingCondition(ServerWebExchange exchange) {
-		if (this.patterns.isEmpty()) {
-			return this;
-		}
 		SortedSet<PathPattern> matches = getMatchingPatterns(exchange);
-		return (!matches.isEmpty() ? new PatternsRequestCondition(matches) : null);
+		return (matches != null ? new PatternsRequestCondition(matches) : null);
 	}
 
-	/**
+	@Nullable
-	 * Find the patterns matching the given lookup path. Invoking this method should
-	 * yield results equivalent to those of calling
-	 * {@link #getMatchingCondition(ServerWebExchange)}.
-	 * This method is provided as an alternative to be used if no request is available
-	 * (e.g. introspection, tooling, etc).
-	 * @param exchange the current exchange
-	 * @return a sorted set of matching patterns sorted with the closest match first
-	 */
 	private SortedSet<PathPattern> getMatchingPatterns(ServerWebExchange exchange) {
 		PathContainer lookupPath = exchange.getRequest().getPath().pathWithinApplication();
-		TreeSet<PathPattern> pathPatterns = new TreeSet<>();
+		TreeSet<PathPattern> result = null;
 		for (PathPattern pattern : this.patterns) {
 			if (pattern.matches(lookupPath)) {
-				pathPatterns.add(pattern);
+				result = (result != null ? result : new TreeSet<>());
+				result.add(pattern);
 			}
 		}
-		return pathPatterns;
+		return result;
 	}
 
 	/**

spring-webflux/src/main/java/org/springframework/web/reactive/result/condition/ProducesRequestCondition.java

@@ -25,6 +25,7 @@ import java.util.Set;
 import org.springframework.http.MediaType;
 import org.springframework.lang.Nullable;
 import org.springframework.util.CollectionUtils;
+import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 import org.springframework.web.accept.ContentNegotiationManager;
 import org.springframework.web.bind.annotation.RequestMapping;
@@ -92,43 +93,45 @@ public final class ProducesRequestCondition extends AbstractRequestCondition<Pro
 	 * @param resolver used to determine requested content type
 	 */
 	public ProducesRequestCondition(String[] produces, String[] headers, RequestedContentTypeResolver resolver) {
-		this.expressions = new ArrayList<>(parseExpressions(produces, headers));
+		this.expressions = parseExpressions(produces, headers);
 		if (this.expressions.size() > 1) {
 			Collections.sort(this.expressions);
 		}
 		this.contentTypeResolver = resolver != null ? resolver : DEFAULT_CONTENT_TYPE_RESOLVER;
 	}
 
-	/**
+	private List<ProduceMediaTypeExpression> parseExpressions(String[] produces, String[] headers) {
-	 * Private constructor for internal use to create matching conditions.
+		Set<ProduceMediaTypeExpression> result = null;
-	 * Note the expressions List is neither sorted, nor deep copied.
+		if (!ObjectUtils.isEmpty(headers)) {
-	 */
-	private ProducesRequestCondition(List<ProduceMediaTypeExpression> expressions, ProducesRequestCondition other) {
-		this.expressions = expressions;
-		this.contentTypeResolver = other.contentTypeResolver;
-	}
-
-
-	private Set<ProduceMediaTypeExpression> parseExpressions(String[] produces, String[] headers) {
-		Set<ProduceMediaTypeExpression> result = new LinkedHashSet<>();
-		if (headers != null) {
 			for (String header : headers) {
 				HeadersRequestCondition.HeaderExpression expr = new HeadersRequestCondition.HeaderExpression(header);
 				if ("Accept".equalsIgnoreCase(expr.name)) {
 					for (MediaType mediaType : MediaType.parseMediaTypes(expr.value)) {
+						result = (result != null ? result : new LinkedHashSet<>());
 						result.add(new ProduceMediaTypeExpression(mediaType, expr.isNegated));
 					}
 				}
 			}
 		}
-		if (produces != null) {
+		if (!ObjectUtils.isEmpty(produces)) {
 			for (String produce : produces) {
+				result = (result != null ? result : new LinkedHashSet<>());
 				result.add(new ProduceMediaTypeExpression(produce));
 			}
 		}
-		return result;
+		return (result != null ? new ArrayList<>(result) : Collections.emptyList());
 	}
 
+	/**
+	 * Private constructor for internal use to create matching conditions.
+	 * Note the expressions List is neither sorted, nor deep copied.
+	 */
+	private ProducesRequestCondition(List<ProduceMediaTypeExpression> expressions, ProducesRequestCondition other) {
+		this.expressions = expressions;
+		this.contentTypeResolver = other.contentTypeResolver;
+	}
+
+
 	/**
 	 * Return the contained "produces" expressions.
 	 */

spring-webflux/src/main/java/org/springframework/web/reactive/result/condition/RequestMethodsRequestCondition.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.
@@ -21,13 +21,13 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedHashSet;
-import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
 import org.springframework.http.HttpMethod;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.lang.Nullable;
+import org.springframework.util.ObjectUtils;
 import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.cors.reactive.CorsUtils;
 import org.springframework.web.server.ServerWebExchange;
@@ -62,16 +62,15 @@ public final class RequestMethodsRequestCondition extends AbstractRequestConditi
 	 * if, 0 the condition will match to every request
 	 */
 	public RequestMethodsRequestCondition(RequestMethod... requestMethods) {
-		this(asList(requestMethods));
+		this.methods = (ObjectUtils.isEmpty(requestMethods) ?
+				Collections.emptySet() : new LinkedHashSet<>(Arrays.asList(requestMethods)));
 	}
 
-	private RequestMethodsRequestCondition(Collection<RequestMethod> requestMethods) {
+	/**
-		this.methods = Collections.unmodifiableSet(new LinkedHashSet<>(requestMethods));
+	 * Private constructor for internal use when combining conditions.
-	}
+	 */
-
+	private RequestMethodsRequestCondition(Set<RequestMethod> requestMethods) {
-
+		this.methods = requestMethods;
-	private static List<RequestMethod> asList(RequestMethod... requestMethods) {
-		return (requestMethods != null ? Arrays.asList(requestMethods) : Collections.emptyList());
 	}
 
 
@@ -98,6 +97,15 @@ public final class RequestMethodsRequestCondition extends AbstractRequestConditi
 	 */
 	@Override
 	public RequestMethodsRequestCondition combine(RequestMethodsRequestCondition other) {
+		if (isEmpty() && other.isEmpty()) {
+			return this;
+		}
+		else if (other.isEmpty()) {
+			return this;
+		}
+		else if (isEmpty()) {
+			return other;
+		}
 		Set<RequestMethod> set = new LinkedHashSet<>(this.methods);
 		set.addAll(other.methods);
 		return new RequestMethodsRequestCondition(set);

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/RequestMappingInfo.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.
@@ -16,12 +16,13 @@
 
 package org.springframework.web.reactive.result.method;
 
-import java.util.Arrays;
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Set;
-import java.util.stream.Collectors;
 
 import org.springframework.lang.Nullable;
+import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.reactive.accept.RequestedContentTypeResolver;
@@ -54,6 +55,19 @@ import org.springframework.web.util.pattern.PathPatternParser;
  */
 public final class RequestMappingInfo implements RequestCondition<RequestMappingInfo> {
 
+	private static final PatternsRequestCondition EMPTY_PATTERNS = new PatternsRequestCondition();
+
+	private static final RequestMethodsRequestCondition EMPTY_REQUEST_METHODS = new RequestMethodsRequestCondition();
+
+	private static final ParamsRequestCondition EMPTY_PARAMS = new ParamsRequestCondition();
+
+	private static final HeadersRequestCondition EMPTY_HEADERS = new HeadersRequestCondition();
+
+	private static final ConsumesRequestCondition EMPTY_CONSUMES = new ConsumesRequestCondition();
+
+	private static final ProducesRequestCondition EMPTY_PRODUCES = new ProducesRequestCondition();
+
+
 	@Nullable
 	private final String name;
 
@@ -78,12 +92,12 @@ public final class RequestMappingInfo implements RequestCondition<RequestMapping
 			@Nullable ProducesRequestCondition produces, @Nullable RequestCondition<?> custom) {
 
 		this.name = (StringUtils.hasText(name) ? name : null);
-		this.patternsCondition = (patterns != null ? patterns : new PatternsRequestCondition());
+		this.patternsCondition = (patterns != null ? patterns : EMPTY_PATTERNS);
-		this.methodsCondition = (methods != null ? methods : new RequestMethodsRequestCondition());
+		this.methodsCondition = (methods != null ? methods : EMPTY_REQUEST_METHODS);
-		this.paramsCondition = (params != null ? params : new ParamsRequestCondition());
+		this.paramsCondition = (params != null ? params : EMPTY_PARAMS);
-		this.headersCondition = (headers != null ? headers : new HeadersRequestCondition());
+		this.headersCondition = (headers != null ? headers : EMPTY_HEADERS);
-		this.consumesCondition = (consumes != null ? consumes : new ConsumesRequestCondition());
+		this.consumesCondition = (consumes != null ? consumes : EMPTY_CONSUMES);
-		this.producesCondition = (produces != null ? produces : new ProducesRequestCondition());
+		this.producesCondition = (produces != null ? produces : EMPTY_PRODUCES);
 		this.customConditionHolder = new RequestConditionHolder(custom);
 	}
 
@@ -430,6 +444,10 @@ public final class RequestMappingInfo implements RequestCondition<RequestMapping
 		@Nullable
 		private String[] produces;
 
+		private boolean hasContentType;
+
+		private boolean hasAccept;
+
 		@Nullable
 		private String mappingName;
 
@@ -438,6 +456,7 @@ public final class RequestMappingInfo implements RequestCondition<RequestMapping
 
 		private BuilderConfiguration options = new BuilderConfiguration();
 
+
 		public DefaultBuilder(String... paths) {
 			this.paths = paths;
 		}
@@ -462,6 +481,12 @@ public final class RequestMappingInfo implements RequestCondition<RequestMapping
 
 		@Override
 		public DefaultBuilder headers(String... headers) {
+			for (String header : headers) {
+				this.hasContentType = this.hasContentType ||
+						header.contains("Content-Type") || header.contains("content-type");
+				this.hasAccept = this.hasAccept ||
+						header.contains("Accept") || header.contains("accept");
+			}
 			this.headers = headers;
 			return this;
 		}
@@ -498,31 +523,50 @@ public final class RequestMappingInfo implements RequestCondition<RequestMapping
 
 		@Override
 		public RequestMappingInfo build() {
-			RequestedContentTypeResolver contentTypeResolver = this.options.getContentTypeResolver();
 
 			PathPatternParser parser = (this.options.getPatternParser() != null ?
 					this.options.getPatternParser() : new PathPatternParser());
-			PatternsRequestCondition patternsCondition = new PatternsRequestCondition(parse(this.paths, parser));
+
-
+			RequestedContentTypeResolver contentTypeResolver = this.options.getContentTypeResolver();
-			return new RequestMappingInfo(this.mappingName, patternsCondition,
+
-					new RequestMethodsRequestCondition(this.methods),
+			return new RequestMappingInfo(this.mappingName,
-					new ParamsRequestCondition(this.params),
+					isEmpty(this.paths) ? null : new PatternsRequestCondition(parse(this.paths, parser)),
-					new HeadersRequestCondition(this.headers),
+					ObjectUtils.isEmpty(this.methods) ?
-					new ConsumesRequestCondition(this.consumes, this.headers),
+							null : new RequestMethodsRequestCondition(this.methods),
-					new ProducesRequestCondition(this.produces, this.headers, contentTypeResolver),
+					ObjectUtils.isEmpty(this.params) ?
+							null : new ParamsRequestCondition(this.params),
+					ObjectUtils.isEmpty(this.headers) ?
+							null : new HeadersRequestCondition(this.headers),
+					ObjectUtils.isEmpty(this.consumes) && !this.hasContentType ?
+							null : new ConsumesRequestCondition(this.consumes, this.headers),
+					ObjectUtils.isEmpty(this.produces) && !this.hasAccept ?
+							null : new ProducesRequestCondition(this.produces, this.headers, contentTypeResolver),
 					this.customCondition);
 		}
 
-		private static List<PathPattern> parse(String[] paths, PathPatternParser parser) {
+		private static List<PathPattern> parse(String[] patterns, PathPatternParser parser) {
-			return Arrays
+			if (isEmpty(patterns)) {
-					.stream(paths)
+				return Collections.emptyList();
-					.map(path -> {
+			}
-						if (StringUtils.hasText(path) && !path.startsWith("/")) {
+			List<PathPattern> result = new ArrayList<>(patterns.length);
-							path = "/" + path;
+			for (String path : patterns) {
-						}
+				if (StringUtils.hasText(path) && !path.startsWith("/")) {
-						return parser.parse(path);
+					path = "/" + path;
-					})
+				}
-					.collect(Collectors.toList());
+				result.add(parser.parse(path));
+			}
+			return result;
+		}
+
+		private static boolean isEmpty(String[] patterns) {
+			if (!ObjectUtils.isEmpty(patterns)) {
+				for (String pattern : patterns) {
+					if (StringUtils.hasText(pattern)) {
+						return false;
+					}
+				}
+			}
+			return true;
 		}
 	}
 

spring-webflux/src/test/java/org/springframework/web/reactive/result/condition/PatternsRequestConditionTests.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.
@@ -42,15 +42,19 @@ public class PatternsRequestConditionTests {
 	@Test
 	public void prependNonEmptyPatternsOnly() {
 		PatternsRequestCondition c = createPatternsCondition("");
-		assertThat(c.getPatterns().iterator().next().getPatternString()).as("Do not prepend empty patterns (SPR-8255)").isEqualTo("");
+		assertThat(c.getPatterns().iterator().next().getPatternString())
+				.as("Do not prepend empty patterns (SPR-8255)")
+				.isEqualTo("");
 	}
 
 	@Test
 	public void combineEmptySets() {
 		PatternsRequestCondition c1 = new PatternsRequestCondition();
 		PatternsRequestCondition c2 = new PatternsRequestCondition();
+		PatternsRequestCondition c3 = c1.combine(c2);
 
-		assertThat(c1.combine(c2)).isEqualTo(createPatternsCondition());
+		assertThat(c3).isSameAs(c1);
+		assertThat(c1.getPatterns()).isSameAs(c2.getPatterns()).containsExactly(this.parser.parse(""));
 	}
 
 	@Test
@@ -75,7 +79,7 @@ public class PatternsRequestConditionTests {
 	}
 
 	@Test
-	public void matchDirectPath() throws Exception {
+	public void matchDirectPath() {
 		PatternsRequestCondition condition = createPatternsCondition("/foo");
 		MockServerWebExchange exchange = MockServerWebExchange.from(get("/foo"));
 		PatternsRequestCondition match = condition.getMatchingCondition(exchange);
@@ -84,7 +88,7 @@ public class PatternsRequestConditionTests {
 	}
 
 	@Test
-	public void matchPattern() throws Exception {
+	public void matchPattern() {
 		PatternsRequestCondition condition = createPatternsCondition("/foo/*");
 		MockServerWebExchange exchange = MockServerWebExchange.from(get("/foo/bar"));
 		PatternsRequestCondition match = condition.getMatchingCondition(exchange);
@@ -93,7 +97,7 @@ public class PatternsRequestConditionTests {
 	}
 
 	@Test
-	public void matchSortPatterns() throws Exception {
+	public void matchSortPatterns() {
 		PatternsRequestCondition condition = createPatternsCondition("/*/*", "/foo/bar", "/foo/*");
 		MockServerWebExchange exchange = MockServerWebExchange.from(get("/foo/bar"));
 		PatternsRequestCondition match = condition.getMatchingCondition(exchange);
@@ -103,20 +107,24 @@ public class PatternsRequestConditionTests {
 	}
 
 	@Test
-	public void matchTrailingSlash() throws Exception {
+	public void matchTrailingSlash() {
 		MockServerWebExchange exchange = MockServerWebExchange.from(get("/foo/"));
 
 		PatternsRequestCondition condition = createPatternsCondition("/foo");
 		PatternsRequestCondition match = condition.getMatchingCondition(exchange);
 
 		assertThat(match).isNotNull();
-		assertThat(match.getPatterns().iterator().next().getPatternString()).as("Should match by default").isEqualTo("/foo");
+		assertThat(match.getPatterns().iterator().next().getPatternString())
+				.as("Should match by default")
+				.isEqualTo("/foo");
 
 		condition = createPatternsCondition("/foo");
 		match = condition.getMatchingCondition(exchange);
 
 		assertThat(match).isNotNull();
-		assertThat(match.getPatterns().iterator().next().getPatternString()).as("Trailing slash should be insensitive to useSuffixPatternMatch settings (SPR-6164, SPR-5636)").isEqualTo("/foo");
+		assertThat(match.getPatterns().iterator().next().getPatternString())
+				.as("Trailing slash should be insensitive to useSuffixPatternMatch settings (SPR-6164, SPR-5636)")
+				.isEqualTo("/foo");
 
 		PathPatternParser parser = new PathPatternParser();
 		parser.setMatchOptionalTrailingSeparator(false);
@@ -127,7 +135,7 @@ public class PatternsRequestConditionTests {
 	}
 
 	@Test
-	public void matchPatternContainsExtension() throws Exception {
+	public void matchPatternContainsExtension() {
 		PatternsRequestCondition condition = createPatternsCondition("/foo.jpg");
 		MockServerWebExchange exchange = MockServerWebExchange.from(get("/foo.html"));
 		PatternsRequestCondition match = condition.getMatchingCondition(exchange);
@@ -138,18 +146,16 @@ public class PatternsRequestConditionTests {
 	@Test // gh-22543
 	public void matchWithEmptyPatterns() {
 		PatternsRequestCondition condition = new PatternsRequestCondition();
-		assertThat(condition).isEqualTo(new PatternsRequestCondition(this.parser.parse("")));
 		assertThat(condition.getMatchingCondition(MockServerWebExchange.from(get("")))).isNotNull();
 		assertThat(condition.getMatchingCondition(MockServerWebExchange.from(get("/anything")))).isNull();
 
 		condition = condition.combine(new PatternsRequestCondition());
-		assertThat(condition).isEqualTo(new PatternsRequestCondition(this.parser.parse("")));
 		assertThat(condition.getMatchingCondition(MockServerWebExchange.from(get("")))).isNotNull();
 		assertThat(condition.getMatchingCondition(MockServerWebExchange.from(get("/anything")))).isNull();
 	}
 
 	@Test
-	public void compareToConsistentWithEquals() throws Exception {
+	public void compareToConsistentWithEquals() {
 		PatternsRequestCondition c1 = createPatternsCondition("/foo*");
 		PatternsRequestCondition c2 = createPatternsCondition("/foo*");
 
@@ -157,7 +163,7 @@ public class PatternsRequestConditionTests {
 	}
 
 	@Test
-	public void equallyMatchingPatternsAreBothPresent() throws Exception {
+	public void equallyMatchingPatternsAreBothPresent() {
 		PatternsRequestCondition c = createPatternsCondition("/a", "/b");
 		assertThat(c.getPatterns().size()).isEqualTo(2);
 		Iterator<PathPattern> itr = c.getPatterns().iterator();
@@ -166,7 +172,7 @@ public class PatternsRequestConditionTests {
 	}
 
 	@Test
-	public void comparePatternSpecificity() throws Exception {
+	public void comparePatternSpecificity() {
 		ServerWebExchange exchange = MockServerWebExchange.from(get("/foo"));
 
 		PatternsRequestCondition c1 = createPatternsCondition("/fo*");
@@ -177,11 +183,13 @@ public class PatternsRequestConditionTests {
 		c1 = createPatternsCondition("/fo*");
 		c2 = createPatternsCondition("/*oo");
 
-		assertThat(c1.compareTo(c2, exchange)).as("Patterns are equally specific even if not the same").isEqualTo(0);
+		assertThat(c1.compareTo(c2, exchange))
+				.as("Patterns are equally specific even if not the same")
+				.isEqualTo(0);
 	}
 
 	@Test
-	public void compareNumberOfMatchingPatterns() throws Exception {
+	public void compareNumberOfMatchingPatterns() {
 		ServerWebExchange exchange = MockServerWebExchange.from(get("/foo.html"));
 
 		PatternsRequestCondition c1 = createPatternsCondition("/foo.*", "/foo.jpeg");
@@ -197,7 +205,7 @@ public class PatternsRequestConditionTests {
 	private PatternsRequestCondition createPatternsCondition(String... patterns) {
 		return new PatternsRequestCondition(Arrays
 				.stream(patterns)
-				.map(rawPattern -> this.parser.parse(rawPattern))
+				.map(this.parser::parse)
 				.collect(Collectors.toList()));
 	}
 

spring-webflux/src/test/java/org/springframework/web/reactive/result/condition/RequestMappingInfoTests.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.
@@ -49,7 +49,6 @@ public class RequestMappingInfoTests {
 
 	// TODO: CORS pre-flight (see @Disabled)
 
-
 	@Test
 	public void createEmpty() {
 		RequestMappingInfo info = paths().build();
@@ -62,6 +61,22 @@ public class RequestMappingInfoTests {
 		assertThat(info.getParamsCondition()).isNotNull();
 		assertThat(info.getHeadersCondition()).isNotNull();
 		assertThat(info.getCustomCondition()).isNull();
+
+		RequestMappingInfo anotherInfo = paths().build();
+		assertThat(info.getPatternsCondition()).isSameAs(anotherInfo.getPatternsCondition());
+		assertThat(info.getMethodsCondition()).isSameAs(anotherInfo.getMethodsCondition());
+		assertThat(info.getParamsCondition()).isSameAs(anotherInfo.getParamsCondition());
+		assertThat(info.getHeadersCondition()).isSameAs(anotherInfo.getHeadersCondition());
+		assertThat(info.getConsumesCondition()).isSameAs(anotherInfo.getConsumesCondition());
+		assertThat(info.getProducesCondition()).isSameAs(anotherInfo.getProducesCondition());
+
+		RequestMappingInfo result = info.combine(anotherInfo);
+		assertThat(info.getPatternsCondition()).isSameAs(result.getPatternsCondition());
+		assertThat(info.getMethodsCondition()).isSameAs(result.getMethodsCondition());
+		assertThat(info.getParamsCondition()).isSameAs(result.getParamsCondition());
+		assertThat(info.getHeadersCondition()).isSameAs(result.getHeadersCondition());
+		assertThat(info.getConsumesCondition()).isSameAs(result.getConsumesCondition());
+		assertThat(info.getProducesCondition()).isSameAs(result.getProducesCondition());
 	}
 
 	@Test

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/condition/ConsumesRequestCondition.java

@@ -30,6 +30,7 @@ import org.springframework.http.InvalidMediaTypeException;
 import org.springframework.http.MediaType;
 import org.springframework.lang.Nullable;
 import org.springframework.util.CollectionUtils;
+import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.cors.CorsUtils;
@@ -76,37 +77,40 @@ public final class ConsumesRequestCondition extends AbstractRequestCondition<Con
 	 * @param headers as described in {@link RequestMapping#headers()}
 	 */
 	public ConsumesRequestCondition(String[] consumes, @Nullable String[] headers) {
-		this.expressions = new ArrayList<>(parseExpressions(consumes, headers));
+		this.expressions = parseExpressions(consumes, headers);
 		if (this.expressions.size() > 1) {
 			Collections.sort(this.expressions);
 		}
 	}
 
-	/**
+	private static List<ConsumeMediaTypeExpression> parseExpressions(String[] consumes, @Nullable String[] headers) {
-	 * Private constructor for internal when creating matching conditions.
+		Set<ConsumeMediaTypeExpression> result = null;
-	 * Note the expressions List is neither sorted nor deep copied.
+		if (!ObjectUtils.isEmpty(headers)) {
-	 */
-	private ConsumesRequestCondition(List<ConsumeMediaTypeExpression> expressions) {
-		this.expressions = expressions;
-	}
-
-
-	private static Set<ConsumeMediaTypeExpression> parseExpressions(String[] consumes, @Nullable String[] headers) {
-		Set<ConsumeMediaTypeExpression> result = new LinkedHashSet<>();
-		if (headers != null) {
 			for (String header : headers) {
 				HeaderExpression expr = new HeaderExpression(header);
 				if ("Content-Type".equalsIgnoreCase(expr.name) && expr.value != null) {
+					result = (result != null ? result : new LinkedHashSet<>());
 					for (MediaType mediaType : MediaType.parseMediaTypes(expr.value)) {
 						result.add(new ConsumeMediaTypeExpression(mediaType, expr.isNegated));
 					}
 				}
 			}
 		}
-		for (String consume : consumes) {
+		if (!ObjectUtils.isEmpty(consumes)) {
-			result.add(new ConsumeMediaTypeExpression(consume));
+			result = (result != null ? result : new LinkedHashSet<>());
+			for (String consume : consumes) {
+				result.add(new ConsumeMediaTypeExpression(consume));
+			}
 		}
-		return result;
+		return (result != null ? new ArrayList<>(result) : Collections.emptyList());
+	}
+
+	/**
+	 * Private constructor for internal when creating matching conditions.
+	 * Note the expressions List is neither sorted nor deep copied.
+	 */
+	private ConsumesRequestCondition(List<ConsumeMediaTypeExpression> expressions) {
+		this.expressions = expressions;
 	}
 
 

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/condition/HeadersRequestCondition.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.
@@ -17,6 +17,7 @@
 package org.springframework.web.servlet.mvc.condition;
 
 import java.util.Collection;
+import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.Set;
 
@@ -55,26 +56,29 @@ public final class HeadersRequestCondition extends AbstractRequestCondition<Head
 	 * if 0, the condition will match to every request
 	 */
 	public HeadersRequestCondition(String... headers) {
-		this(parseExpressions(headers));
+		this.expressions = parseExpressions(headers);
 	}
 
-	private HeadersRequestCondition(Set<HeaderExpression> conditions) {
-		this.expressions = conditions;
-	}
-
-
 	private static Set<HeaderExpression> parseExpressions(String... headers) {
-		Set<HeaderExpression> expressions = new LinkedHashSet<>();
+		Set<HeaderExpression> result = null;
-		for (String header : headers) {
+		if (!ObjectUtils.isEmpty(headers)) {
-			HeaderExpression expr = new HeaderExpression(header);
+			for (String header : headers) {
-			if ("Accept".equalsIgnoreCase(expr.name) || "Content-Type".equalsIgnoreCase(expr.name)) {
+				HeaderExpression expr = new HeaderExpression(header);
-				continue;
+				if ("Accept".equalsIgnoreCase(expr.name) || "Content-Type".equalsIgnoreCase(expr.name)) {
+					continue;
+				}
+				result = (result != null ? result : new LinkedHashSet<>(headers.length));
+				result.add(expr);
 			}
-			expressions.add(expr);
 		}
-		return expressions;
+		return (result != null ? result : Collections.emptySet());
 	}
 
+	private HeadersRequestCondition(Set<HeaderExpression> conditions) {
+		this.expressions = conditions;
+	}
+
+
 	/**
 	 * Return the contained request header expressions.
 	 */
@@ -98,6 +102,15 @@ public final class HeadersRequestCondition extends AbstractRequestCondition<Head
 	 */
 	@Override
 	public HeadersRequestCondition combine(HeadersRequestCondition other) {
+		if (isEmpty() && other.isEmpty()) {
+			return this;
+		}
+		else if (other.isEmpty()) {
+			return this;
+		}
+		else if (isEmpty()) {
+			return other;
+		}
 		Set<HeaderExpression> set = new LinkedHashSet<>(this.expressions);
 		set.addAll(other.expressions);
 		return new HeadersRequestCondition(set);
@@ -157,7 +170,7 @@ public final class HeadersRequestCondition extends AbstractRequestCondition<Head
 	 */
 	static class HeaderExpression extends AbstractNameValueExpression<String> {
 
-		public HeaderExpression(String expression) {
+		HeaderExpression(String expression) {
 			super(expression);
 		}
 

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/condition/ParamsRequestCondition.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.
@@ -48,22 +48,24 @@ public final class ParamsRequestCondition extends AbstractRequestCondition<Param
 	 * 	if 0, the condition will match to every request.
 	 */
 	public ParamsRequestCondition(String... params) {
-		this(parseExpressions(params));
+		this.expressions = parseExpressions(params);
 	}
 
-	private ParamsRequestCondition(Collection<ParamExpression> conditions) {
+	private static Set<ParamExpression> parseExpressions(String... params) {
-		this.expressions = Collections.unmodifiableSet(new LinkedHashSet<>(conditions));
+		if (ObjectUtils.isEmpty(params)) {
-	}
+			return Collections.emptySet();
-
+		}
-
+		Set<ParamExpression> expressions = new LinkedHashSet<>(params.length);
-	private static Collection<ParamExpression> parseExpressions(String... params) {
-		Set<ParamExpression> expressions = new LinkedHashSet<>();
 		for (String param : params) {
 			expressions.add(new ParamExpression(param));
 		}
 		return expressions;
 	}
 
+	private ParamsRequestCondition(Set<ParamExpression> conditions) {
+		this.expressions = conditions;
+	}
+
 
 	/**
 	 * Return the contained request parameter expressions.
@@ -88,6 +90,15 @@ public final class ParamsRequestCondition extends AbstractRequestCondition<Param
 	 */
 	@Override
 	public ParamsRequestCondition combine(ParamsRequestCondition other) {
+		if (isEmpty() && other.isEmpty()) {
+			return this;
+		}
+		else if (other.isEmpty()) {
+			return this;
+		}
+		else if (isEmpty()) {
+			return other;
+		}
 		Set<ParamExpression> set = new LinkedHashSet<>(this.expressions);
 		set.addAll(other.expressions);
 		return new ParamsRequestCondition(set);

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/condition/PatternsRequestCondition.java

@@ -17,7 +17,6 @@
 package org.springframework.web.servlet.mvc.condition;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
@@ -30,6 +29,7 @@ import javax.servlet.http.HttpServletRequest;
 
 import org.springframework.lang.Nullable;
 import org.springframework.util.AntPathMatcher;
+import org.springframework.util.ObjectUtils;
 import org.springframework.util.PathMatcher;
 import org.springframework.util.StringUtils;
 import org.springframework.web.servlet.HandlerMapping;
@@ -42,7 +42,10 @@ import org.springframework.web.util.UrlPathHelper;
  * @author Rossen Stoyanchev
  * @since 3.1
  */
-public final class PatternsRequestCondition extends AbstractRequestCondition<PatternsRequestCondition> {
+public class PatternsRequestCondition extends AbstractRequestCondition<PatternsRequestCondition> {
+
+	private final static Set<String> EMPTY_PATH_PATTERN = Collections.singleton("");
+
 
 	private final Set<String> patterns;
 
@@ -64,7 +67,7 @@ public final class PatternsRequestCondition extends AbstractRequestCondition<Pat
 	 * every request.
 	 */
 	public PatternsRequestCondition(String... patterns) {
-		this(Arrays.asList(patterns), null, null, true, true, null);
+		this(patterns, null, null, true, true, null);
 	}
 
 	/**
@@ -79,7 +82,7 @@ public final class PatternsRequestCondition extends AbstractRequestCondition<Pat
 	public PatternsRequestCondition(String[] patterns, @Nullable UrlPathHelper urlPathHelper,
 			@Nullable PathMatcher pathMatcher, boolean useTrailingSlashMatch) {
 
-		this(Arrays.asList(patterns), urlPathHelper, pathMatcher, false, useTrailingSlashMatch, null);
+		this(patterns, urlPathHelper, pathMatcher, false, useTrailingSlashMatch, null);
 	}
 
 	/**
@@ -97,7 +100,7 @@ public final class PatternsRequestCondition extends AbstractRequestCondition<Pat
 	public PatternsRequestCondition(String[] patterns, @Nullable UrlPathHelper urlPathHelper,
 			@Nullable PathMatcher pathMatcher, boolean useSuffixPatternMatch, boolean useTrailingSlashMatch) {
 
-		this(Arrays.asList(patterns), urlPathHelper, pathMatcher, useSuffixPatternMatch, useTrailingSlashMatch, null);
+		this(patterns, urlPathHelper, pathMatcher, useSuffixPatternMatch, useTrailingSlashMatch, null);
 	}
 
 	/**
@@ -117,18 +120,7 @@ public final class PatternsRequestCondition extends AbstractRequestCondition<Pat
 			@Nullable PathMatcher pathMatcher, boolean useSuffixPatternMatch,
 			boolean useTrailingSlashMatch, @Nullable List<String> fileExtensions) {
 
-		this(Arrays.asList(patterns), urlPathHelper, pathMatcher, useSuffixPatternMatch,
+		this.patterns = initPatterns(patterns);
-				useTrailingSlashMatch, fileExtensions);
-	}
-
-	/**
-	 * Private constructor accepting a collection of patterns.
-	 */
-	private PatternsRequestCondition(Collection<String> patterns, @Nullable UrlPathHelper urlPathHelper,
-			@Nullable PathMatcher pathMatcher, boolean useSuffixPatternMatch,
-			boolean useTrailingSlashMatch, @Nullable List<String> fileExtensions) {
-
-		this.patterns = Collections.unmodifiableSet(prependLeadingSlash(patterns));
 		this.pathHelper = urlPathHelper != null ? urlPathHelper : UrlPathHelper.defaultInstance;
 		this.pathMatcher = pathMatcher != null ? pathMatcher : new AntPathMatcher();
 		this.useSuffixPatternMatch = useSuffixPatternMatch;
@@ -144,6 +136,31 @@ public final class PatternsRequestCondition extends AbstractRequestCondition<Pat
 		}
 	}
 
+	private static Set<String> initPatterns(String[] patterns) {
+		if (!hasPattern(patterns)) {
+			return EMPTY_PATH_PATTERN;
+		}
+		Set<String> result = new LinkedHashSet<>(patterns.length);
+		for (String pattern : patterns) {
+			if (StringUtils.hasLength(pattern) && !pattern.startsWith("/")) {
+				pattern = "/" + pattern;
+			}
+			result.add(pattern);
+		}
+		return result;
+	}
+
+	private static boolean hasPattern(String[] patterns) {
+		if (!ObjectUtils.isEmpty(patterns)) {
+			for (String pattern : patterns) {
+				if (StringUtils.hasText(pattern)) {
+					return true;
+				}
+			}
+		}
+		return false;
+	}
+
 	/**
 	 * Private constructor for use when combining and matching.
 	 */
@@ -157,20 +174,6 @@ public final class PatternsRequestCondition extends AbstractRequestCondition<Pat
 	}
 
 
-	private static Set<String> prependLeadingSlash(Collection<String> patterns) {
-		if (patterns.isEmpty()) {
-			return Collections.singleton("");
-		}
-		Set<String> result = new LinkedHashSet<>(patterns.size());
-		for (String pattern : patterns) {
-			if (StringUtils.hasLength(pattern) && !pattern.startsWith("/")) {
-				pattern = "/" + pattern;
-			}
-			result.add(pattern);
-		}
-		return result;
-	}
-
 	public Set<String> getPatterns() {
 		return this.patterns;
 	}
@@ -197,6 +200,15 @@ public final class PatternsRequestCondition extends AbstractRequestCondition<Pat
 	 */
 	@Override
 	public PatternsRequestCondition combine(PatternsRequestCondition other) {
+		if (isEmptyPathPattern() && other.isEmptyPathPattern()) {
+			return this;
+		}
+		else if (other.isEmptyPathPattern()) {
+			return this;
+		}
+		else if (isEmptyPathPattern()) {
+			return other;
+		}
 		Set<String> result = new LinkedHashSet<>();
 		if (!this.patterns.isEmpty() && !other.patterns.isEmpty()) {
 			for (String pattern1 : this.patterns) {
@@ -205,18 +217,13 @@ public final class PatternsRequestCondition extends AbstractRequestCondition<Pat
 				}
 			}
 		}
-		else if (!this.patterns.isEmpty()) {
-			result.addAll(this.patterns);
-		}
-		else if (!other.patterns.isEmpty()) {
-			result.addAll(other.patterns);
-		}
-		else {
-			result.add("");
-		}
 		return new PatternsRequestCondition(result, this);
 	}
 
+	private boolean isEmptyPathPattern() {
+		return this.patterns == EMPTY_PATH_PATTERN;
+	}
+
 	/**
 	 * Checks if any of the patterns match the given request and returns an instance
 	 * that is guaranteed to contain matching patterns, sorted via
@@ -236,9 +243,6 @@ public final class PatternsRequestCondition extends AbstractRequestCondition<Pat
 	@Override
 	@Nullable
 	public PatternsRequestCondition getMatchingCondition(HttpServletRequest request) {
-		if (this.patterns.isEmpty()) {
-			return this;
-		}
 		String lookupPath = this.pathHelper.getLookupPathForRequest(request, HandlerMapping.LOOKUP_PATH);
 		List<String> matches = getMatchingPatterns(lookupPath);
 		return !matches.isEmpty() ? new PatternsRequestCondition(new LinkedHashSet<>(matches), this) : null;
@@ -257,7 +261,7 @@ public final class PatternsRequestCondition extends AbstractRequestCondition<Pat
 		for (String pattern : this.patterns) {
 			String match = getMatchingPattern(pattern, lookupPath);
 			if (match != null) {
-				matches = matches != null ? matches : new ArrayList<>();
+				matches = (matches != null ? matches : new ArrayList<>());
 				matches.add(match);
 			}
 		}

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/condition/ProducesRequestCondition.java

@@ -27,6 +27,7 @@ import javax.servlet.http.HttpServletRequest;
 import org.springframework.http.MediaType;
 import org.springframework.lang.Nullable;
 import org.springframework.util.CollectionUtils;
+import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 import org.springframework.web.HttpMediaTypeException;
 import org.springframework.web.HttpMediaTypeNotAcceptableException;
@@ -96,41 +97,45 @@ public final class ProducesRequestCondition extends AbstractRequestCondition<Pro
 	public ProducesRequestCondition(String[] produces, @Nullable String[] headers,
 			@Nullable ContentNegotiationManager manager) {
 
-		this.expressions = new ArrayList<>(parseExpressions(produces, headers));
+		this.expressions = parseExpressions(produces, headers);
 		if (this.expressions.size() > 1) {
 			Collections.sort(this.expressions);
 		}
 		this.contentNegotiationManager = manager != null ? manager : DEFAULT_CONTENT_NEGOTIATION_MANAGER;
 	}
 
-	/**
+	private List<ProduceMediaTypeExpression> parseExpressions(String[] produces, @Nullable String[] headers) {
-	 * Private constructor for internal use to create matching conditions.
+		Set<ProduceMediaTypeExpression> result = null;
-	 * Note the expressions List is neither sorted nor deep copied.
+		if (!ObjectUtils.isEmpty(headers)) {
-	 */
-	private ProducesRequestCondition(List<ProduceMediaTypeExpression> expressions, ProducesRequestCondition other) {
-		this.expressions = expressions;
-		this.contentNegotiationManager = other.contentNegotiationManager;
-	}
-
-
-	private Set<ProduceMediaTypeExpression> parseExpressions(String[] produces, @Nullable String[] headers) {
-		Set<ProduceMediaTypeExpression> result = new LinkedHashSet<>();
-		if (headers != null) {
 			for (String header : headers) {
 				HeaderExpression expr = new HeaderExpression(header);
 				if ("Accept".equalsIgnoreCase(expr.name) && expr.value != null) {
 					for (MediaType mediaType : MediaType.parseMediaTypes(expr.value)) {
+						result = (result != null ? result : new LinkedHashSet<>());
 						result.add(new ProduceMediaTypeExpression(mediaType, expr.isNegated));
 					}
 				}
 			}
 		}
-		for (String produce : produces) {
+		if (!ObjectUtils.isEmpty(produces)) {
-			result.add(new ProduceMediaTypeExpression(produce));
+			for (String produce : produces) {
+				result = (result != null ? result : new LinkedHashSet<>());
+				result.add(new ProduceMediaTypeExpression(produce));
+			}
 		}
-		return result;
+		return (result != null ? new ArrayList<>(result) : Collections.emptyList());
 	}
 
+	/**
+	 * Private constructor for internal use to create matching conditions.
+	 * Note the expressions List is neither sorted nor deep copied.
+	 */
+	private ProducesRequestCondition(List<ProduceMediaTypeExpression> expressions, ProducesRequestCondition other) {
+		this.expressions = expressions;
+		this.contentNegotiationManager = other.contentNegotiationManager;
+	}
+
+
 	/**
 	 * Return the contained "produces" expressions.
 	 */

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/condition/RequestMethodsRequestCondition.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.
@@ -30,6 +30,7 @@ import javax.servlet.http.HttpServletRequest;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
 import org.springframework.lang.Nullable;
+import org.springframework.util.ObjectUtils;
 import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.cors.CorsUtils;
 
@@ -63,11 +64,15 @@ public final class RequestMethodsRequestCondition extends AbstractRequestConditi
 	 * if, 0 the condition will match to every request
 	 */
 	public RequestMethodsRequestCondition(RequestMethod... requestMethods) {
-		this(Arrays.asList(requestMethods));
+		this.methods = (ObjectUtils.isEmpty(requestMethods) ?
+				Collections.emptySet() : new LinkedHashSet<>(Arrays.asList(requestMethods)));
 	}
 
-	private RequestMethodsRequestCondition(Collection<RequestMethod> requestMethods) {
+	/**
-		this.methods = Collections.unmodifiableSet(new LinkedHashSet<>(requestMethods));
+	 * Private constructor for internal use when combining conditions.
+	 */
+	private RequestMethodsRequestCondition(Set<RequestMethod> methods) {
+		this.methods = methods;
 	}
 
 
@@ -94,6 +99,15 @@ public final class RequestMethodsRequestCondition extends AbstractRequestConditi
 	 */
 	@Override
 	public RequestMethodsRequestCondition combine(RequestMethodsRequestCondition other) {
+		if (isEmpty() && other.isEmpty()) {
+			return this;
+		}
+		else if (other.isEmpty()) {
+			return this;
+		}
+		else if (isEmpty()) {
+			return other;
+		}
 		Set<RequestMethod> set = new LinkedHashSet<>(this.methods);
 		set.addAll(other.methods);
 		return new RequestMethodsRequestCondition(set);

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/RequestMappingInfo.java

@@ -23,6 +23,7 @@ import javax.servlet.http.HttpServletRequest;
 
 import org.springframework.http.HttpMethod;
 import org.springframework.lang.Nullable;
+import org.springframework.util.ObjectUtils;
 import org.springframework.util.PathMatcher;
 import org.springframework.util.StringUtils;
 import org.springframework.web.accept.ContentNegotiationManager;
@@ -56,6 +57,19 @@ import org.springframework.web.util.UrlPathHelper;
  */
 public final class RequestMappingInfo implements RequestCondition<RequestMappingInfo> {
 
+	private static final PatternsRequestCondition EMPTY_PATTERNS = new PatternsRequestCondition();
+
+	private static final RequestMethodsRequestCondition EMPTY_REQUEST_METHODS = new RequestMethodsRequestCondition();
+
+	private static final ParamsRequestCondition EMPTY_PARAMS = new ParamsRequestCondition();
+
+	private static final HeadersRequestCondition EMPTY_HEADERS = new HeadersRequestCondition();
+
+	private static final ConsumesRequestCondition EMPTY_CONSUMES = new ConsumesRequestCondition();
+
+	private static final ProducesRequestCondition EMPTY_PRODUCES = new ProducesRequestCondition();
+
+
 	@Nullable
 	private final String name;
 
@@ -80,12 +94,12 @@ public final class RequestMappingInfo implements RequestCondition<RequestMapping
 			@Nullable ProducesRequestCondition produces, @Nullable RequestCondition<?> custom) {
 
 		this.name = (StringUtils.hasText(name) ? name : null);
-		this.patternsCondition = (patterns != null ? patterns : new PatternsRequestCondition());
+		this.patternsCondition = (patterns != null ? patterns : EMPTY_PATTERNS);
-		this.methodsCondition = (methods != null ? methods : new RequestMethodsRequestCondition());
+		this.methodsCondition = (methods != null ? methods : EMPTY_REQUEST_METHODS);
-		this.paramsCondition = (params != null ? params : new ParamsRequestCondition());
+		this.paramsCondition = (params != null ? params : EMPTY_PARAMS);
-		this.headersCondition = (headers != null ? headers : new HeadersRequestCondition());
+		this.headersCondition = (headers != null ? headers : EMPTY_HEADERS);
-		this.consumesCondition = (consumes != null ? consumes : new ConsumesRequestCondition());
+		this.consumesCondition = (consumes != null ? consumes : EMPTY_CONSUMES);
-		this.producesCondition = (produces != null ? produces : new ProducesRequestCondition());
+		this.producesCondition = (produces != null ? produces : EMPTY_PRODUCES);
 		this.customConditionHolder = new RequestConditionHolder(custom);
 	}
 
@@ -427,7 +441,7 @@ public final class RequestMappingInfo implements RequestCondition<RequestMapping
 
 	private static class DefaultBuilder implements Builder {
 
-		private String[] paths = new String[0];
+		private String[] paths;
 
 		private RequestMethod[] methods = new RequestMethod[0];
 
@@ -439,6 +453,10 @@ public final class RequestMappingInfo implements RequestCondition<RequestMapping
 
 		private String[] produces = new String[0];
 
+		private boolean hasContentType;
+
+		private boolean hasAccept;
+
 		@Nullable
 		private String mappingName;
 
@@ -471,6 +489,12 @@ public final class RequestMappingInfo implements RequestCondition<RequestMapping
 
 		@Override
 		public DefaultBuilder headers(String... headers) {
+			for (String header : headers) {
+				this.hasContentType = this.hasContentType ||
+						header.contains("Content-Type") || header.contains("content-type");
+				this.hasAccept = this.hasAccept ||
+						header.contains("Accept") || header.contains("accept");
+			}
 			this.headers = headers;
 			return this;
 		}
@@ -508,19 +532,26 @@ public final class RequestMappingInfo implements RequestCondition<RequestMapping
 		@Override
 		@SuppressWarnings("deprecation")
 		public RequestMappingInfo build() {
-			ContentNegotiationManager manager = this.options.getContentNegotiationManager();
 
-			PatternsRequestCondition patternsCondition = new PatternsRequestCondition(
+			PatternsRequestCondition patternsCondition = ObjectUtils.isEmpty(this.paths) ? null :
-					this.paths, this.options.getUrlPathHelper(), this.options.getPathMatcher(),
+					new PatternsRequestCondition(
-					this.options.useSuffixPatternMatch(), this.options.useTrailingSlashMatch(),
+							this.paths, this.options.getUrlPathHelper(), this.options.getPathMatcher(),
-					this.options.getFileExtensions());
+							this.options.useSuffixPatternMatch(), this.options.useTrailingSlashMatch(),
+							this.options.getFileExtensions());
+
+			ContentNegotiationManager manager = this.options.getContentNegotiationManager();
 
 			return new RequestMappingInfo(this.mappingName, patternsCondition,
-					new RequestMethodsRequestCondition(this.methods),
+					ObjectUtils.isEmpty(this.methods) ?
-					new ParamsRequestCondition(this.params),
+							null : new RequestMethodsRequestCondition(this.methods),
-					new HeadersRequestCondition(this.headers),
+					ObjectUtils.isEmpty(this.params) ?
-					new ConsumesRequestCondition(this.consumes, this.headers),
+							null : new ParamsRequestCondition(this.params),
-					new ProducesRequestCondition(this.produces, this.headers, manager),
+					ObjectUtils.isEmpty(this.headers) ?
+							null : new HeadersRequestCondition(this.headers),
+					ObjectUtils.isEmpty(this.consumes) && !this.hasContentType ?
+							null : new ConsumesRequestCondition(this.consumes, this.headers),
+					ObjectUtils.isEmpty(this.produces) && !this.hasAccept ?
+							null : new ProducesRequestCondition(this.produces, this.headers, manager),
 					this.customCondition);
 		}
 	}

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/condition/PatternsRequestConditionTests.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.
@@ -17,7 +17,7 @@
 package org.springframework.web.servlet.mvc.condition;
 
 import java.util.Arrays;
-import java.util.List;
+import java.util.Collections;
 
 import javax.servlet.http.HttpServletRequest;
 
@@ -48,8 +48,10 @@ public class PatternsRequestConditionTests {
 	public void combineEmptySets() {
 		PatternsRequestCondition c1 = new PatternsRequestCondition();
 		PatternsRequestCondition c2 = new PatternsRequestCondition();
+		PatternsRequestCondition c3 = c1.combine(c2);
 
-		assertThat(c1.combine(c2)).isEqualTo(new PatternsRequestCondition(""));
+		assertThat(c3).isSameAs(c1);
+		assertThat(c1.getPatterns()).isSameAs(c2.getPatterns()).containsExactly("");
 	}
 
 	@Test
@@ -118,9 +120,8 @@ public class PatternsRequestConditionTests {
 
 	@Test // SPR-8410
 	public void matchSuffixPatternUsingFileExtensions() {
-		String[] patterns = new String[] {"/jobs/{jobName}"};
+		PatternsRequestCondition condition = new PatternsRequestCondition(
-		List<String> extensions = Arrays.asList("json");
+				new String[] {"/jobs/{jobName}"}, null, null, true, false, Collections.singletonList("json"));
-		PatternsRequestCondition condition = new PatternsRequestCondition(patterns, null, null, true, false, extensions);
 
 		MockHttpServletRequest request = new MockHttpServletRequest("GET", "/jobs/my.job");
 		PatternsRequestCondition match = condition.getMatchingCondition(request);
@@ -165,9 +166,11 @@ public class PatternsRequestConditionTests {
 		match = condition.getMatchingCondition(request);
 
 		assertThat(match).isNotNull();
-		assertThat(match.getPatterns().iterator().next()).as("Trailing slash should be insensitive to useSuffixPatternMatch settings (SPR-6164, SPR-5636)").isEqualTo("/foo/");
+		assertThat(match.getPatterns().iterator().next())
+				.as("Trailing slash should be insensitive to useSuffixPatternMatch settings (SPR-6164, SPR-5636)")
+				.isEqualTo("/foo/");
 
-		condition = new PatternsRequestCondition(new String[] {"/foo"}, null, null, false, false);
+		condition = new PatternsRequestCondition(new String[] {"/foo"}, null, null, false);
 		match = condition.getMatchingCondition(request);
 
 		assertThat(match).isNull();
@@ -175,8 +178,8 @@ public class PatternsRequestConditionTests {
 
 	@Test
 	public void matchPatternContainsExtension() {
-		PatternsRequestCondition condition = new PatternsRequestCondition("/foo.jpg");
+		MockHttpServletRequest request = new MockHttpServletRequest("GET", "/foo.html");
-		PatternsRequestCondition match = condition.getMatchingCondition(new MockHttpServletRequest("GET", "/foo.html"));
+		PatternsRequestCondition match = new PatternsRequestCondition("/foo.jpg").getMatchingCondition(request);
 
 		assertThat(match).isNull();
 	}
@@ -184,12 +187,10 @@ public class PatternsRequestConditionTests {
 	@Test // gh-22543
 	public void matchWithEmptyPatterns() {
 		PatternsRequestCondition condition = new PatternsRequestCondition();
-		assertThat(condition).isEqualTo(new PatternsRequestCondition(""));
 		assertThat(condition.getMatchingCondition(new MockHttpServletRequest("GET", ""))).isNotNull();
 		assertThat(condition.getMatchingCondition(new MockHttpServletRequest("GET", "/anything"))).isNull();
 
 		condition = condition.combine(new PatternsRequestCondition());
-		assertThat(condition).isEqualTo(new PatternsRequestCondition(""));
 		assertThat(condition.getMatchingCondition(new MockHttpServletRequest("GET", ""))).isNotNull();
 		assertThat(condition.getMatchingCondition(new MockHttpServletRequest("GET", "/anything"))).isNull();
 	}
@@ -211,7 +212,7 @@ public class PatternsRequestConditionTests {
 	}
 
 	@Test
-	public void compareNumberOfMatchingPatterns() throws Exception {
+	public void compareNumberOfMatchingPatterns() {
 		HttpServletRequest request = new MockHttpServletRequest("GET", "/foo.html");
 
 		PatternsRequestCondition c1 = new PatternsRequestCondition("/foo", "*.jpeg");

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/RequestMappingInfoTests.java

@@ -44,16 +44,33 @@ public class RequestMappingInfoTests {
 
 	@Test
 	public void createEmpty() {
+
 		RequestMappingInfo info = paths().build();
 
 		// gh-22543
 		assertThat(info.getPatternsCondition().getPatterns()).isEqualTo(Collections.singleton(""));
 		assertThat(info.getMethodsCondition().getMethods().size()).isEqualTo(0);
-		assertThat(info.getConsumesCondition().isEmpty()).isEqualTo(true);
-		assertThat(info.getProducesCondition().isEmpty()).isEqualTo(true);
 		assertThat(info.getParamsCondition()).isNotNull();
 		assertThat(info.getHeadersCondition()).isNotNull();
+		assertThat(info.getConsumesCondition().isEmpty()).isEqualTo(true);
+		assertThat(info.getProducesCondition().isEmpty()).isEqualTo(true);
 		assertThat(info.getCustomCondition()).isNull();
+
+		RequestMappingInfo anotherInfo = paths().build();
+		assertThat(info.getPatternsCondition()).isSameAs(anotherInfo.getPatternsCondition());
+		assertThat(info.getMethodsCondition()).isSameAs(anotherInfo.getMethodsCondition());
+		assertThat(info.getParamsCondition()).isSameAs(anotherInfo.getParamsCondition());
+		assertThat(info.getHeadersCondition()).isSameAs(anotherInfo.getHeadersCondition());
+		assertThat(info.getConsumesCondition()).isSameAs(anotherInfo.getConsumesCondition());
+		assertThat(info.getProducesCondition()).isSameAs(anotherInfo.getProducesCondition());
+
+		RequestMappingInfo result = info.combine(anotherInfo);
+		assertThat(info.getPatternsCondition()).isSameAs(result.getPatternsCondition());
+		assertThat(info.getMethodsCondition()).isSameAs(result.getMethodsCondition());
+		assertThat(info.getParamsCondition()).isSameAs(result.getParamsCondition());
+		assertThat(info.getHeadersCondition()).isSameAs(result.getHeadersCondition());
+		assertThat(info.getConsumesCondition()).isSameAs(result.getConsumesCondition());
+		assertThat(info.getProducesCondition()).isSameAs(result.getProducesCondition());
 	}
 
 	@Test