Add support for webjars-locator-lite

This is a follow-up to spring-projects/spring-framework#27619
This commit adds support for "org.webjars:webjars-locator-lite" for
enabling the statis resources chain.

As of this commit, support for "org.webjars:webjars-locator-core" is
deprecated for obvious performance reasons.

Closes gh-40146

Author: bclozel

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/ConditionalOnEnabledResourceChain.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2022 the original author or authors.
+ * Copyright 2012-2024 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 +27,10 @@
 /**
  * {@link Conditional @Conditional} that checks whether the Spring resource handling chain
  * is enabled. Matches if {@link WebProperties.Resources.Chain#getEnabled()} is
- * {@code true} or if {@code webjars-locator-core} is on the classpath.
+ * {@code true} or if one of {@code "org.webjars:webjars-locator-core"},
+ * {@code "org.webjars:webjars-locator-lite"} is on the classpath.
+ * <p>
+ * Note that support for {@code "org.webjars:webjars-locator-core"} is deprecated.
  *
  * @author Stephane Nicoll
  * @since 1.3.0

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/OnEnabledResourceChainCondition.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2022 the original author or authors.
+ * Copyright 2012-2024 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.
@@ -32,12 +32,15 @@
  * @author Stephane Nicoll
  * @author Phillip Webb
  * @author Madhura Bhave
+ * @author Brian Clozel
  * @see ConditionalOnEnabledResourceChain
  */
 class OnEnabledResourceChainCondition extends SpringBootCondition {
 
 	private static final String WEBJAR_ASSET_LOCATOR = "org.webjars.WebJarAssetLocator";
 
+	private static final String WEBJAR_VERSION_LOCATOR = "org.webjars.WebJarVersionLocator";
+
 	@Override
 	public ConditionOutcome getMatchOutcome(ConditionContext context, AnnotatedTypeMetadata metadata) {
 		ConfigurableEnvironment environment = (ConfigurableEnvironment) context.getEnvironment();
@@ -47,10 +50,13 @@ public ConditionOutcome getMatchOutcome(ConditionContext context, AnnotatedTypeM
 		Boolean match = Chain.getEnabled(fixed, content, chain);
 		ConditionMessage.Builder message = ConditionMessage.forCondition(ConditionalOnEnabledResourceChain.class);
 		if (match == null) {
+			if (ClassUtils.isPresent(WEBJAR_VERSION_LOCATOR, getClass().getClassLoader())) {
+				return ConditionOutcome.match(message.found("class").items(WEBJAR_VERSION_LOCATOR));
+			}
 			if (ClassUtils.isPresent(WEBJAR_ASSET_LOCATOR, getClass().getClassLoader())) {
 				return ConditionOutcome.match(message.found("class").items(WEBJAR_ASSET_LOCATOR));
 			}
-			return ConditionOutcome.noMatch(message.didNotFind("class").items(WEBJAR_ASSET_LOCATOR));
+			return ConditionOutcome.noMatch(message.didNotFind("class").items(WEBJAR_VERSION_LOCATOR));
 		}
 		if (match) {
 			return ConditionOutcome.match(message.because("enabled"));

spring-boot-project/spring-boot-dependencies/build.gradle

@@ -2206,6 +2206,13 @@ bom {
 			]
 		}
 	}
+	library("WebJars Locator Lite", "1.0.0") {
+		group("org.webjars") {
+			modules = [
+				"webjars-locator-lite"
+			]
+		}
+	}
 	library("WebJars Locator Core", "0.59") {
 		group("org.webjars") {
 			modules = [

spring-boot-project/spring-boot-docs/src/docs/antora/modules/reference/pages/web/servlet.adoc

@@ -145,13 +145,10 @@ Although this directory is a common standard, it works *only* with war packaging
 
 Spring Boot also supports the advanced resource handling features provided by Spring MVC, allowing use cases such as cache-busting static resources or using version agnostic URLs for Webjars.
 
-To use version agnostic URLs for Webjars, add the `webjars-locator-core` dependency.
+To use version agnostic URLs for Webjars, add the `org.webjars:webjars-locator-lite` dependency.
 Then declare your Webjar.
 Using jQuery as an example, adding `"/webjars/jquery/jquery.min.js"` results in `"/webjars/jquery/x.y.z/jquery.min.js"` where `x.y.z` is the Webjar version.
 
-NOTE: If you use JBoss, you need to declare the `webjars-locator-jboss-vfs` dependency instead of the `webjars-locator-core`.
-Otherwise, all Webjars resolve as a `404`.
-
 To use cache busting, the following configuration configures a cache busting solution for all static resources, effectively adding a content hash, such as `<link href="/css/spring-2a2d595e6ed9a0b24f027f2b63b134d6.css"/>`, in URLs:
 
 [configprops,yaml]