Simplify WebJars support

Author: vpavic

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/ResourceChainRegistration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -27,7 +27,6 @@
 import org.springframework.web.servlet.resource.CachingResourceResolver;
 import org.springframework.web.servlet.resource.CachingResourceTransformer;
 import org.springframework.web.servlet.resource.CssLinkResourceTransformer;
-import org.springframework.web.servlet.resource.LiteWebJarsResourceResolver;
 import org.springframework.web.servlet.resource.PathResourceResolver;
 import org.springframework.web.servlet.resource.ResourceResolver;
 import org.springframework.web.servlet.resource.ResourceTransformer;
@@ -83,7 +82,6 @@ public ResourceChainRegistration(boolean cacheResources, @Nullable Cache cache)
 	 * @param resolver the resolver to add
 	 * @return the current instance for chained method invocation
 	 */
-	@SuppressWarnings("removal")
 	public ResourceChainRegistration addResolver(ResourceResolver resolver) {
 		Assert.notNull(resolver, "The provided ResourceResolver should not be null");
 		this.resolvers.add(resolver);
@@ -93,7 +91,7 @@ public ResourceChainRegistration addResolver(ResourceResolver resolver) {
 		else if (resolver instanceof PathResourceResolver) {
 			this.hasPathResolver = true;
 		}
-		else if (resolver instanceof WebJarsResourceResolver || resolver instanceof LiteWebJarsResourceResolver) {
+		else if (resolver instanceof WebJarsResourceResolver) {
 			this.hasWebjarsResolver = true;
 		}
 		return this;
@@ -118,10 +116,10 @@ protected List<ResourceResolver> getResourceResolvers() {
 		if (!this.hasPathResolver) {
 			List<ResourceResolver> result = new ArrayList<>(this.resolvers);
 			if (isWebJarVersionLocatorPresent && !this.hasWebjarsResolver) {
-				result.add(new LiteWebJarsResourceResolver());
+				result.add(new WebJarsResourceResolver());
 			}
 			else if (isWebJarAssetLocatorPresent && !this.hasWebjarsResolver) {
-				result.add(new WebJarsResourceResolver());
+				result.add(new WebJarsResourceResolver(new org.webjars.WebJarAssetLocator()));
 			}
 			result.add(new PathResourceResolver());
 			return result;

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/LiteWebJarsResourceResolver.java

@@ -17,9 +17,11 @@
 package org.springframework.web.servlet.resource;
 
 import java.util.List;
+import java.util.function.BiFunction;
 
 import jakarta.servlet.http.HttpServletRequest;
 import org.webjars.WebJarAssetLocator;
+import org.webjars.WebJarVersionLocator;
 
 import org.springframework.core.io.Resource;
 import org.springframework.lang.Nullable;
@@ -46,34 +48,38 @@
  * @since 4.2
  * @see org.springframework.web.servlet.config.annotation.ResourceChainRegistration
  * @see <a href="https://www.webjars.org">webjars.org</a>
- * @see LiteWebJarsResourceResolver
- * @deprecated as of Spring Framework 6.2 in favor of {@link LiteWebJarsResourceResolver}
  */
-@Deprecated(forRemoval = true)
 public class WebJarsResourceResolver extends AbstractResourceResolver {
 
-	private static final String WEBJARS_LOCATION = "META-INF/resources/webjars/";
+	private static final int WEBJARS_LOCATION_LENGTH = "META-INF/resources/webjars/".length();
 
-	private static final int WEBJARS_LOCATION_LENGTH = WEBJARS_LOCATION.length();
-
-
-	private final WebJarAssetLocator webJarAssetLocator;
+	private final BiFunction<String, String, String> webJarVersionLocator;
 
 
 	/**
-	 * Create a {@code WebJarsResourceResolver} with a default {@code WebJarAssetLocator} instance.
+	 * Create a {@code WebJarsResourceResolver} with a default {@code WebJarVersionLocator} instance.
 	 */
 	public WebJarsResourceResolver() {
-		this(new WebJarAssetLocator());
+		this(new WebJarVersionLocator());
+	}
+
+	/**
+	 * Create a {@code WebJarsResourceResolver} with a custom {@code WebJarVersionLocator} instance,
+	 * e.g. with a custom cache implementation.
+	 */
+	public WebJarsResourceResolver(WebJarVersionLocator webJarVersionLocator) {
+		this.webJarVersionLocator = webJarVersionLocator::fullPath;
 	}
 
 	/**
 	 * Create a {@code WebJarsResourceResolver} with a custom {@code WebJarAssetLocator} instance,
 	 * e.g. with a custom index.
 	 * @since 4.3
+	 * @deprecated as of Spring Framework 6.2
 	 */
+	@Deprecated(forRemoval = true)
 	public WebJarsResourceResolver(WebJarAssetLocator webJarAssetLocator) {
-		this.webJarAssetLocator = webJarAssetLocator;
+		this.webJarVersionLocator = webJarAssetLocator::getFullPathExact;
 	}
 
 
@@ -109,12 +115,12 @@ protected String resolveUrlPathInternal(String resourceUrlPath,
 
 	@Nullable
 	protected String findWebJarResourcePath(String path) {
-		int startOffset = (path.startsWith("/") ? 1 : 0);
 		int endOffset = path.indexOf('/', 1);
 		if (endOffset != -1) {
+			int startOffset = (path.startsWith("/") ? 1 : 0);
 			String webjar = path.substring(startOffset, endOffset);
 			String partialPath = path.substring(endOffset + 1);
-			String webJarPath = this.webJarAssetLocator.getFullPathExact(webjar, partialPath);
+			String webJarPath = this.webJarVersionLocator.apply(webjar, partialPath);
 			if (webJarPath != null) {
 				return webJarPath.substring(WEBJARS_LOCATION_LENGTH);
 			}

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/WebJarsResourceResolver.java

@@ -31,12 +31,12 @@
 import org.springframework.web.servlet.resource.CachingResourceResolver;
 import org.springframework.web.servlet.resource.CachingResourceTransformer;
 import org.springframework.web.servlet.resource.CssLinkResourceTransformer;
-import org.springframework.web.servlet.resource.LiteWebJarsResourceResolver;
 import org.springframework.web.servlet.resource.PathResourceResolver;
 import org.springframework.web.servlet.resource.ResourceHttpRequestHandler;
 import org.springframework.web.servlet.resource.ResourceResolver;
 import org.springframework.web.servlet.resource.ResourceTransformer;
 import org.springframework.web.servlet.resource.VersionResourceResolver;
+import org.springframework.web.servlet.resource.WebJarsResourceResolver;
 import org.springframework.web.testfixture.servlet.MockHttpServletRequest;
 import org.springframework.web.testfixture.servlet.MockHttpServletResponse;
 import org.springframework.web.testfixture.servlet.MockServletContext;
@@ -140,7 +140,7 @@ void resourceChain() {
 				zero -> assertThat(zero).isInstanceOfSatisfying(CachingResourceResolver.class,
 						cachingResolver -> assertThat(cachingResolver.getCache()).isInstanceOf(ConcurrentMapCache.class)),
 				one -> assertThat(one).isEqualTo(mockResolver),
-				two -> assertThat(two).isInstanceOf(LiteWebJarsResourceResolver.class),
+				two -> assertThat(two).isInstanceOf(WebJarsResourceResolver.class),
 				three -> assertThat(three).isInstanceOf(PathResourceResolver.class));
 		assertThat(handler.getResourceTransformers()).satisfiesExactly(
 				zero -> assertThat(zero).isInstanceOf(CachingResourceTransformer.class),
@@ -153,7 +153,7 @@ void resourceChainWithoutCaching() {
 
 		ResourceHttpRequestHandler handler = getHandler("/resources/**");
 		assertThat(handler.getResourceResolvers()).hasExactlyElementsOfTypes(
-				LiteWebJarsResourceResolver.class, PathResourceResolver.class);
+				WebJarsResourceResolver.class, PathResourceResolver.class);
 		assertThat(handler.getResourceTransformers()).isEmpty();
 	}
 
@@ -169,7 +169,7 @@ void resourceChainWithVersionResolver() {
 		assertThat(handler.getResourceResolvers()).satisfiesExactly(
 				zero -> assertThat(zero).isInstanceOf(CachingResourceResolver.class),
 				one -> assertThat(one).isSameAs(versionResolver),
-				two -> assertThat(two).isInstanceOf(LiteWebJarsResourceResolver.class),
+				two -> assertThat(two).isInstanceOf(WebJarsResourceResolver.class),
 				three -> assertThat(three).isInstanceOf(PathResourceResolver.class));
 		assertThat(handler.getResourceTransformers()).hasExactlyElementsOfTypes(
 				CachingResourceTransformer.class, CssLinkResourceTransformer.class);
@@ -179,7 +179,7 @@ void resourceChainWithVersionResolver() {
 	void resourceChainWithOverrides() {
 		CachingResourceResolver cachingResolver = mock();
 		VersionResourceResolver versionResolver = mock();
-		LiteWebJarsResourceResolver webjarsResolver = mock();
+		WebJarsResourceResolver webjarsResolver = mock();
 		PathResourceResolver pathResourceResolver = new PathResourceResolver();
 		CachingResourceTransformer cachingTransformer = mock();
 		CssLinkResourceTransformer cssLinkTransformer = new CssLinkResourceTransformer();