Add classpath index support for exploded war archives

Update the Maven and Gradle packaging for war files so that a
`classpath.idx` file is written into the archive that provides the
original order of the classpath, as was previously done for jar files.
The `WarLauncher` class will use this file when running as an exploded
archive to ensure that the classpath order is the same as when running
from the far war.

Fixes gh-19875

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/bundling/BootWar.java

@@ -41,6 +41,7 @@ import org.gradle.api.tasks.bundling.War;
  *
  * @author Andy Wilkinson
  * @author Phillip Webb
+ * @author Scott Frederick
  * @since 2.0.0
  */
 public class BootWar extends War implements BootArchive {
@@ -55,6 +56,8 @@ public class BootWar extends War implements BootArchive {
 
 	private static final String LAYERS_INDEX = "WEB-INF/layers.idx";
 
+	private static final String CLASSPATH_INDEX = "WEB-INF/classpath.idx";
+
 	private final BootArchiveSupport support;
 
 	private final Property<String> mainClass;
@@ -91,8 +94,8 @@ public class BootWar extends War implements BootArchive {
 
 	@Override
 	public void copy() {
-		this.support.configureManifest(getManifest(), getMainClass().get(), CLASSES_DIRECTORY, LIB_DIRECTORY, null,
+		this.support.configureManifest(getManifest(), getMainClass().get(), CLASSES_DIRECTORY, LIB_DIRECTORY,
-				(isLayeredDisabled()) ? null : LAYERS_INDEX);
+				CLASSPATH_INDEX, (isLayeredDisabled()) ? null : LAYERS_INDEX);
 		super.copy();
 	}
 

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/bundling/AbstractBootArchiveTests.java

@@ -500,9 +500,7 @@ abstract class AbstractBootArchiveTests<T extends Jar & BootArchive> {
 			expected.add("- \"application\":");
 			Set<String> applicationContents = new TreeSet<>();
 			applicationContents.add("  - \"" + this.classesPath + "\"");
-			if (archiveHasClasspathIndex()) {
 			applicationContents.add("  - \"" + this.indexPath + "classpath.idx\"");
-			}
 			applicationContents.add("  - \"" + this.indexPath + "layers.idx\"");
 			applicationContents.add("  - \"META-INF/\"");
 			expected.addAll(applicationContents);
@@ -551,9 +549,7 @@ abstract class AbstractBootArchiveTests<T extends Jar & BootArchive> {
 			Set<String> applicationContents = new TreeSet<>();
 			applicationContents.add("  - \"" + this.classesPath + "application.properties\"");
 			applicationContents.add("  - \"" + this.classesPath + "com/\"");
-			if (archiveHasClasspathIndex()) {
 			applicationContents.add("  - \"" + this.indexPath + "classpath.idx\"");
-			}
 			applicationContents.add("  - \"" + this.indexPath + "layers.idx\"");
 			applicationContents.add("  - \"META-INF/\"");
 			applicationContents.add("  - \"org/\"");
@@ -634,12 +630,14 @@ abstract class AbstractBootArchiveTests<T extends Jar & BootArchive> {
 		return getTask().getArchiveFile().get().getAsFile();
 	}
 
-	abstract void applyLayered(Action<LayeredSpec> action);
+	File createPopulatedJar() throws IOException {
-
+		addContent();
-	boolean archiveHasClasspathIndex() {
+		executeTask();
-		return true;
+		return getTask().getArchiveFile().get().getAsFile();
 	}
 
+	abstract void applyLayered(Action<LayeredSpec> action);
+
 	@SuppressWarnings("unchecked")
 	void addContent() throws IOException {
 		this.task.getMainClass().set("com.example.Main");

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/bundling/BootJarTests.java

@@ -103,12 +103,6 @@ class BootJarTests extends AbstractBootArchiveTests<BootJar> {
 		}
 	}
 
-	private File createPopulatedJar() throws IOException {
-		addContent();
-		executeTask();
-		return getTask().getArchiveFile().get().getAsFile();
-	}
-
 	@Override
 	void applyLayered(Action<LayeredSpec> action) {
 		getTask().layered(action);

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/bundling/BootWarIntegrationTests.java

@@ -26,6 +26,7 @@ import org.springframework.boot.gradle.junit.GradleCompatibility;
  * Integration tests for {@link BootWar}.
  *
  * @author Andy Wilkinson
+ * @author Scott Frederick
  */
 @GradleCompatibility(configurationCache = true)
 class BootWarIntegrationTests extends AbstractBootArchiveIntegrationTests {
@@ -37,7 +38,7 @@ class BootWarIntegrationTests extends AbstractBootArchiveIntegrationTests {
 	@Override
 	String[] getExpectedApplicationLayerContents(String... additionalFiles) {
 		Set<String> contents = new TreeSet<>(Arrays.asList(additionalFiles));
-		contents.addAll(Arrays.asList("WEB-INF/layers.idx", "META-INF/"));
+		contents.addAll(Arrays.asList("WEB-INF/classpath.idx", "WEB-INF/layers.idx", "META-INF/"));
 		return contents.toArray(new String[0]);
 	}
 

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/bundling/BootWarTests.java

@@ -30,6 +30,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  * Tests for {@link BootWar}.
  *
  * @author Andy Wilkinson
+ * @author Scott Frederick
  */
 class BootWarTests extends AbstractBootArchiveTests<BootWar> {
 
@@ -109,6 +110,28 @@ class BootWarTests extends AbstractBootArchiveTests<BootWar> {
 				.containsSubsequence("WEB-INF/lib/library.jar", "WEB-INF/lib-provided/provided-library.jar");
 	}
 
+	@Test
+	void whenWarIsLayeredClasspathIndexPointsToLayeredLibs() throws IOException {
+		try (JarFile jarFile = new JarFile(createLayeredJar())) {
+			assertThat(entryLines(jarFile, "WEB-INF/classpath.idx")).containsExactly(
+					"- \"WEB-INF/lib/first-library.jar\"", "- \"WEB-INF/lib/second-library.jar\"",
+					"- \"WEB-INF/lib/third-library-SNAPSHOT.jar\"", "- \"WEB-INF/lib/first-project-library.jar\"",
+					"- \"WEB-INF/lib/second-project-library-SNAPSHOT.jar\"");
+		}
+	}
+
+	@Test
+	void classpathIndexPointsToWebInfLibs() throws IOException {
+		try (JarFile jarFile = new JarFile(createPopulatedJar())) {
+			assertThat(jarFile.getManifest().getMainAttributes().getValue("Spring-Boot-Classpath-Index"))
+					.isEqualTo("WEB-INF/classpath.idx");
+			assertThat(entryLines(jarFile, "WEB-INF/classpath.idx")).containsExactly(
+					"- \"WEB-INF/lib/first-library.jar\"", "- \"WEB-INF/lib/second-library.jar\"",
+					"- \"WEB-INF/lib/third-library-SNAPSHOT.jar\"", "- \"WEB-INF/lib/first-project-library.jar\"",
+					"- \"WEB-INF/lib/second-project-library-SNAPSHOT.jar\"");
+		}
+	}
+
 	@Override
 	protected void executeTask() {
 		getTask().copy();
@@ -124,9 +147,4 @@ class BootWarTests extends AbstractBootArchiveTests<BootWar> {
 		getTask().layered(action);
 	}
 
-	@Override
-	boolean archiveHasClasspathIndex() {
-		return false;
-	}
-
 }

spring-boot-project/spring-boot-tools/spring-boot-loader-tools/src/main/java/org/springframework/boot/loader/tools/Layouts.java

@@ -161,6 +161,11 @@ public final class Layouts {
 			return "WEB-INF/classes/";
 		}
 
+		@Override
+		public String getClasspathIndexFileLocation() {
+			return "WEB-INF/classpath.idx";
+		}
+
 		@Override
 		public String getLayersIndexFileLocation() {
 			return "WEB-INF/layers.idx";

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/ExecutableArchiveLauncher.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -21,9 +21,11 @@ import java.net.URL;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.jar.Attributes;
 import java.util.jar.Manifest;
 
 import org.springframework.boot.loader.archive.Archive;
+import org.springframework.boot.loader.archive.ExplodedArchive;
 
 /**
  * Base class for executable archive {@link Launcher}s.
@@ -31,6 +33,7 @@ import org.springframework.boot.loader.archive.Archive;
  * @author Phillip Webb
  * @author Andy Wilkinson
  * @author Madhura Bhave
+ * @author Scott Frederick
  * @since 1.0.0
  */
 public abstract class ExecutableArchiveLauncher extends Launcher {
@@ -39,6 +42,8 @@ public abstract class ExecutableArchiveLauncher extends Launcher {
 
 	protected static final String BOOT_CLASSPATH_INDEX_ATTRIBUTE = "Spring-Boot-Classpath-Index";
 
+	protected static final String DEFAULT_CLASSPATH_INDEX_FILE_NAME = "classpath.idx";
+
 	private final Archive archive;
 
 	private final ClassPathIndexFile classPathIndex;
@@ -64,9 +69,21 @@ public abstract class ExecutableArchiveLauncher extends Launcher {
 	}
 
 	protected ClassPathIndexFile getClassPathIndex(Archive archive) throws IOException {
+		// Only needed for exploded archives, regular ones already have a defined order
+		if (archive instanceof ExplodedArchive) {
+			String location = getClassPathIndexFileLocation(archive);
+			return ClassPathIndexFile.loadIfPossible(archive.getUrl(), location);
+		}
 		return null;
 	}
 
+	private String getClassPathIndexFileLocation(Archive archive) throws IOException {
+		Manifest manifest = archive.getManifest();
+		Attributes attributes = (manifest != null) ? manifest.getMainAttributes() : null;
+		String location = (attributes != null) ? attributes.getValue(BOOT_CLASSPATH_INDEX_ATTRIBUTE) : null;
+		return (location != null) ? location : getArchiveEntryPathPrefix() + DEFAULT_CLASSPATH_INDEX_FILE_NAME;
+	}
+
 	@Override
 	protected String getMainClass() throws Exception {
 		Manifest manifest = this.archive.getManifest();
@@ -133,8 +150,11 @@ public abstract class ExecutableArchiveLauncher extends Launcher {
 	 * @since 2.3.0
 	 */
 	protected boolean isSearchCandidate(Archive.Entry entry) {
+		if (getArchiveEntryPathPrefix() == null) {
 			return true;
 		}
+		return entry.getName().startsWith(getArchiveEntryPathPrefix());
+	}
 
 	/**
 	 * Determine if the specified entry is a nested item that should be added to the
@@ -166,6 +186,14 @@ public abstract class ExecutableArchiveLauncher extends Launcher {
 	protected void postProcessClassPathArchives(List<Archive> archives) throws Exception {
 	}
 
+	/**
+	 * Return the path prefix for entries in the archive.
+	 * @return the path prefix
+	 */
+	protected String getArchiveEntryPathPrefix() {
+		return null;
+	}
+
 	@Override
 	protected boolean isExploded() {
 		return this.archive.isExploded();

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/JarLauncher.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -16,13 +16,8 @@
 
 package org.springframework.boot.loader;
 
-import java.io.IOException;
-import java.util.jar.Attributes;
-import java.util.jar.Manifest;
-
 import org.springframework.boot.loader.archive.Archive;
 import org.springframework.boot.loader.archive.Archive.EntryFilter;
-import org.springframework.boot.loader.archive.ExplodedArchive;
 
 /**
  * {@link Launcher} for JAR based archives. This launcher assumes that dependency jars are
@@ -32,12 +27,11 @@ import org.springframework.boot.loader.archive.ExplodedArchive;
  * @author Phillip Webb
  * @author Andy Wilkinson
  * @author Madhura Bhave
+ * @author Scott Frederick
  * @since 1.0.0
  */
 public class JarLauncher extends ExecutableArchiveLauncher {
 
-	private static final String DEFAULT_CLASSPATH_INDEX_LOCATION = "BOOT-INF/classpath.idx";
-
 	static final EntryFilter NESTED_ARCHIVE_ENTRY_FILTER = (entry) -> {
 		if (entry.isDirectory()) {
 			return entry.getName().equals("BOOT-INF/classes/");
@@ -52,36 +46,19 @@ public class JarLauncher extends ExecutableArchiveLauncher {
 		super(archive);
 	}
 
-	@Override
-	protected ClassPathIndexFile getClassPathIndex(Archive archive) throws IOException {
-		// Only needed for exploded archives, regular ones already have a defined order
-		if (archive instanceof ExplodedArchive) {
-			String location = getClassPathIndexFileLocation(archive);
-			return ClassPathIndexFile.loadIfPossible(archive.getUrl(), location);
-		}
-		return super.getClassPathIndex(archive);
-	}
-
-	private String getClassPathIndexFileLocation(Archive archive) throws IOException {
-		Manifest manifest = archive.getManifest();
-		Attributes attributes = (manifest != null) ? manifest.getMainAttributes() : null;
-		String location = (attributes != null) ? attributes.getValue(BOOT_CLASSPATH_INDEX_ATTRIBUTE) : null;
-		return (location != null) ? location : DEFAULT_CLASSPATH_INDEX_LOCATION;
-	}
-
 	@Override
 	protected boolean isPostProcessingClassPathArchives() {
 		return false;
 	}
 
 	@Override
-	protected boolean isSearchCandidate(Archive.Entry entry) {
+	protected boolean isNestedArchive(Archive.Entry entry) {
-		return entry.getName().startsWith("BOOT-INF/");
+		return NESTED_ARCHIVE_ENTRY_FILTER.matches(entry);
 	}
 
 	@Override
-	protected boolean isNestedArchive(Archive.Entry entry) {
+	protected String getArchiveEntryPathPrefix() {
-		return NESTED_ARCHIVE_ENTRY_FILTER.matches(entry);
+		return "BOOT-INF/";
 	}
 
 	public static void main(String[] args) throws Exception {

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/WarLauncher.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2021 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 +17,6 @@
 package org.springframework.boot.loader;
 
 import org.springframework.boot.loader.archive.Archive;
-import org.springframework.boot.loader.archive.Archive.Entry;
 
 /**
  * {@link Launcher} for WAR based archives. This launcher for standard WAR archives.
@@ -26,6 +25,7 @@ import org.springframework.boot.loader.archive.Archive.Entry;
  *
  * @author Phillip Webb
  * @author Andy Wilkinson
+ * @author Scott Frederick
  * @since 1.0.0
  */
 public class WarLauncher extends ExecutableArchiveLauncher {
@@ -42,11 +42,6 @@ public class WarLauncher extends ExecutableArchiveLauncher {
 		return false;
 	}
 
-	@Override
-	protected boolean isSearchCandidate(Entry entry) {
-		return entry.getName().startsWith("WEB-INF/");
-	}
-
 	@Override
 	public boolean isNestedArchive(Archive.Entry entry) {
 		if (entry.isDirectory()) {
@@ -55,6 +50,11 @@ public class WarLauncher extends ExecutableArchiveLauncher {
 		return entry.getName().startsWith("WEB-INF/lib/") || entry.getName().startsWith("WEB-INF/lib-provided/");
 	}
 
+	@Override
+	protected String getArchiveEntryPathPrefix() {
+		return "WEB-INF/";
+	}
+
 	public static void main(String[] args) throws Exception {
 		new WarLauncher().launch(args);
 	}

spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/AbstractExecutableArchiveLauncherTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -47,6 +47,7 @@ import org.springframework.util.FileCopyUtils;
  *
  * @author Andy Wilkinson
  * @author Madhura Bhave
+ * @author Scott Frederick
  */
 public abstract class AbstractExecutableArchiveLauncherTests {
 
@@ -80,9 +81,9 @@ public abstract class AbstractExecutableArchiveLauncherTests {
 		if (indexed) {
 			jarOutputStream.putNextEntry(new JarEntry(entryPrefix + "/classpath.idx"));
 			Writer writer = new OutputStreamWriter(jarOutputStream, StandardCharsets.UTF_8);
-			writer.write("- \"BOOT-INF/lib/foo.jar\"\n");
+			writer.write("- \"" + entryPrefix + "/lib/foo.jar\"\n");
-			writer.write("- \"BOOT-INF/lib/bar.jar\"\n");
+			writer.write("- \"" + entryPrefix + "/lib/bar.jar\"\n");
-			writer.write("- \"BOOT-INF/lib/baz.jar\"\n");
+			writer.write("- \"" + entryPrefix + "/lib/baz.jar\"\n");
 			writer.flush();
 			jarOutputStream.closeEntry();
 		}

spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/WarLauncherTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -18,7 +18,11 @@ package org.springframework.boot.loader;
 
 import java.io.File;
 import java.net.URL;
+import java.net.URLClassLoader;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Iterator;
 import java.util.List;
 
 import org.junit.jupiter.api.Test;
@@ -33,6 +37,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  * Tests for {@link WarLauncher}.
  *
  * @author Andy Wilkinson
+ * @author Scott Frederick
  */
 class WarLauncherTests extends AbstractExecutableArchiveLauncherTests {
 
@@ -66,6 +71,29 @@ class WarLauncherTests extends AbstractExecutableArchiveLauncherTests {
 		}
 	}
 
+	@Test
+	void explodedWarShouldPreserveClasspathOrderWhenIndexPresent() throws Exception {
+		File explodedRoot = explode(createJarArchive("archive.war", "WEB-INF", true, Collections.emptyList()));
+		WarLauncher launcher = new WarLauncher(new ExplodedArchive(explodedRoot, true));
+		Iterator<Archive> archives = launcher.getClassPathArchivesIterator();
+		URLClassLoader classLoader = (URLClassLoader) launcher.createClassLoader(archives);
+		URL[] urls = classLoader.getURLs();
+		assertThat(urls).containsExactly(getExpectedFileUrls(explodedRoot));
+	}
+
+	@Test
+	void warFilesPresentInWebInfLibsAndNotInClasspathIndexShouldBeAddedAfterWebInfClasses() throws Exception {
+		ArrayList<String> extraLibs = new ArrayList<>(Arrays.asList("extra-1.jar", "extra-2.jar"));
+		File explodedRoot = explode(createJarArchive("archive.war", "WEB-INF", true, extraLibs));
+		WarLauncher launcher = new WarLauncher(new ExplodedArchive(explodedRoot, true));
+		Iterator<Archive> archives = launcher.getClassPathArchivesIterator();
+		URLClassLoader classLoader = (URLClassLoader) launcher.createClassLoader(archives);
+		URL[] urls = classLoader.getURLs();
+		List<File> expectedFiles = getExpectedFilesWithExtraLibs(explodedRoot);
+		URL[] expectedFileUrls = expectedFiles.stream().map(this::toUrl).toArray(URL[]::new);
+		assertThat(urls).containsExactly(expectedFileUrls);
+	}
+
 	protected final URL[] getExpectedFileUrls(File explodedRoot) {
 		return getExpectedFiles(explodedRoot).stream().map(this::toUrl).toArray(URL[]::new);
 	}
@@ -79,4 +107,15 @@ class WarLauncherTests extends AbstractExecutableArchiveLauncherTests {
 		return expected;
 	}
 
+	protected final List<File> getExpectedFilesWithExtraLibs(File parent) {
+		List<File> expected = new ArrayList<>();
+		expected.add(new File(parent, "WEB-INF/classes"));
+		expected.add(new File(parent, "WEB-INF/lib/extra-1.jar"));
+		expected.add(new File(parent, "WEB-INF/lib/extra-2.jar"));
+		expected.add(new File(parent, "WEB-INF/lib/foo.jar"));
+		expected.add(new File(parent, "WEB-INF/lib/bar.jar"));
+		expected.add(new File(parent, "WEB-INF/lib/baz.jar"));
+		return expected;
+	}
+
 }

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/java/org/springframework/boot/maven/AbstractArchiveIntegrationTests.java

@@ -75,17 +75,20 @@ abstract class AbstractArchiveIntegrationTests {
 			return Collections.emptyMap();
 		}
 		Map<String, List<String>> index = new LinkedHashMap<>();
+		String layerPrefix = "- ";
+		String entryPrefix = "  - ";
 		ZipEntry indexEntry = jarFile.getEntry(getLayersIndexLocation());
 		try (BufferedReader reader = new BufferedReader(new InputStreamReader(jarFile.getInputStream(indexEntry)))) {
 			String line = reader.readLine();
 			String layer = null;
 			while (line != null) {
-				if (line.startsWith("- ")) {
+				if (line.startsWith(layerPrefix)) {
-					layer = line.substring(3, line.length() - 2);
+					layer = line.substring(layerPrefix.length() + 1, line.length() - 2);
 					index.put(layer, new ArrayList<>());
 				}
-				else if (line.startsWith("  - ")) {
+				else if (line.startsWith(entryPrefix)) {
-					index.computeIfAbsent(layer, (key) -> new ArrayList<>()).add(line.substring(5, line.length() - 1));
+					index.computeIfAbsent(layer, (key) -> new ArrayList<>())
+							.add(line.substring(entryPrefix.length() + 1, line.length() - 1));
 				}
 				line = reader.readLine();
 			}
@@ -97,6 +100,22 @@ abstract class AbstractArchiveIntegrationTests {
 		return null;
 	}
 
+	protected List<String> readClasspathIndex(JarFile jarFile, String location) throws IOException {
+		List<String> index = new ArrayList<>();
+		String entryPrefix = "- ";
+		ZipEntry indexEntry = jarFile.getEntry(location);
+		try (BufferedReader reader = new BufferedReader(new InputStreamReader(jarFile.getInputStream(indexEntry)))) {
+			String line = reader.readLine();
+			while (line != null) {
+				if (line.startsWith(entryPrefix)) {
+					index.add(line.substring(entryPrefix.length() + 1, line.length() - 1));
+				}
+				line = reader.readLine();
+			}
+		}
+		return index;
+	}
+
 	static final class JarAssert extends AbstractAssert<JarAssert, File> {
 
 		private JarAssert(File actual) {

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/java/org/springframework/boot/maven/JarIntegrationTests.java

@@ -372,6 +372,10 @@ class JarIntegrationTests extends AbstractArchiveIntegrationTests {
 			assertThat(jar(repackaged)).manifest(
 					(manifest) -> manifest.hasAttribute("Spring-Boot-Classpath-Index", "BOOT-INF/classpath.idx"));
 			assertThat(jar(repackaged)).hasEntryWithName("BOOT-INF/classpath.idx");
+			try (JarFile jarFile = new JarFile(repackaged)) {
+				List<String> index = readClasspathIndex(jarFile, "BOOT-INF/classpath.idx");
+				assertThat(index).allMatch((entry) -> entry.startsWith("BOOT-INF/lib/"));
+			}
 		});
 	}
 

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/java/org/springframework/boot/maven/WarIntegrationTests.java

@@ -211,12 +211,17 @@ class WarIntegrationTests extends AbstractArchiveIntegrationTests {
 	}
 
 	@TestTemplate
-	void repackagedWarDoesNotContainClasspathIndex(MavenBuild mavenBuild) {
+	void repackagedWarContainsClasspathIndex(MavenBuild mavenBuild) {
 		mavenBuild.project("war").execute((project) -> {
 			File repackaged = new File(project, "target/war-0.0.1.BUILD-SNAPSHOT.war");
-			assertThat(jar(repackaged))
+			assertThat(jar(repackaged)).manifest(
-					.manifest((manifest) -> manifest.doesNotHaveAttribute("Spring-Boot-Classpath-Index"));
+					(manifest) -> manifest.hasAttribute("Spring-Boot-Classpath-Index", "WEB-INF/classpath.idx"));
-			assertThat(jar(repackaged)).doesNotHaveEntryWithName("BOOT-INF/classpath.idx");
+			assertThat(jar(repackaged)).hasEntryWithName("WEB-INF/classpath.idx");
+			try (JarFile jarFile = new JarFile(repackaged)) {
+				List<String> index = readClasspathIndex(jarFile, "WEB-INF/classpath.idx");
+				assertThat(index).allMatch(
+						(entry) -> entry.startsWith("WEB-INF/lib/") || entry.startsWith("WEB-INF/lib-provided/"));
+			}
 		});
 	}