Fix classpath index so entries match those expected by the launcher

This reverts commit ad164269e9 and adds
some additional tests.

Fixes gh-24192

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/com/example/bootjar/classpath/BootJarClasspathApplication.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2012-2019 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example.bootjar.classpath;
+
+import java.net.URL;
+import java.net.URLClassLoader;
+
+/**
+ * Application used for testing classpath handling with BootJar.
+ *
+ * @author Andy Wilkinson
+ */
+public class BootJarClasspathApplication {
+
+	protected BootJarClasspathApplication() {
+
+	}
+
+	public static void main(String[] args) {
+		int i = 1;
+		ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
+		for (URL url : ((URLClassLoader) classLoader).getURLs()) {
+			System.out.println(i++ + ". " + url.getFile());
+		}
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/com/example/bootrun/classpath/BootRunClasspathApplication.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.example.classpath;
+package com.example.bootrun.classpath;
 
 import java.io.File;
 import java.lang.management.ManagementFactory;

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/com/example/bootrun/jvmargs/BootRunJvmArgsApplication.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.example.jvmargs;
+package com.example.bootrun.jvmargs;
 
 import java.lang.management.ManagementFactory;
 

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

@@ -44,6 +44,7 @@ import org.gradle.testkit.runner.UnexpectedBuildFailure;
 import org.junit.jupiter.api.TestTemplate;
 
 import org.springframework.boot.loader.tools.JarModeLibrary;
+import org.springframework.util.FileSystemUtils;
 import org.springframework.util.StringUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -240,6 +241,28 @@ class BootJarIntegrationTests extends AbstractBootArchiveIntegrationTests {
 		assertExtractedLayers(layerNames, indexedLayers);
 	}
 
+	@TestTemplate
+	void packagedApplicationClasspath() throws IOException {
+		copyClasspathApplication();
+		BuildResult result = this.gradleBuild.build("launch");
+		String output = result.getOutput();
+		assertThat(output).containsPattern("1\\. .*classes");
+		assertThat(output).containsPattern("2\\. .*library-1.0-SNAPSHOT.jar");
+		assertThat(output).containsPattern("3\\. .*commons-lang3-3.9.jar");
+		assertThat(output).doesNotContain("4. ");
+	}
+
+	@TestTemplate
+	void explodedApplicationClasspath() throws IOException {
+		copyClasspathApplication();
+		BuildResult result = this.gradleBuild.build("launch");
+		String output = result.getOutput();
+		assertThat(output).containsPattern("1\\. .*classes");
+		assertThat(output).containsPattern("2\\. .*library-1.0-SNAPSHOT.jar");
+		assertThat(output).containsPattern("3\\. .*commons-lang3-3.9.jar");
+		assertThat(output).doesNotContain("4. ");
+	}
+
 	private void assertExtractedLayers(List<String> layerNames, Map<String, List<String>> indexedLayers)
 			throws IOException {
 		Map<String, List<String>> extractedLayers = readExtractedLayers(this.gradleBuild.getProjectDir(), layerNames);
@@ -339,4 +362,14 @@ class BootJarIntegrationTests extends AbstractBootArchiveIntegrationTests {
 		return extractedLayers;
 	}
 
+	private void copyClasspathApplication() throws IOException {
+		copyApplication("classpath");
+	}
+
+	private void copyApplication(String name) throws IOException {
+		File output = new File(this.gradleBuild.getProjectDir(), "src/main/java/com/example/bootjar/" + name);
+		output.mkdirs();
+		FileSystemUtils.copyRecursively(new File("src/test/java/com/example/bootjar/" + name), output);
+	}
+
 }

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/bundling/BootJarTests.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.
@@ -200,9 +200,10 @@ class BootJarTests extends AbstractBootArchiveTests<TestBootJar> {
 	@Test
 	void whenJarIsLayeredClasspathIndexPointsToLayeredLibs() throws IOException {
 		try (JarFile jarFile = new JarFile(createLayeredJar())) {
-			assertThat(entryLines(jarFile, "BOOT-INF/classpath.idx")).containsExactly("- \"first-library.jar\"",
-					"- \"second-library.jar\"", "- \"third-library-SNAPSHOT.jar\"", "- \"first-project-library.jar\"",
-					"- \"second-project-library-SNAPSHOT.jar\"");
+			assertThat(entryLines(jarFile, "BOOT-INF/classpath.idx")).containsExactly(
+					"- \"BOOT-INF/lib/first-library.jar\"", "- \"BOOT-INF/lib/second-library.jar\"",
+					"- \"BOOT-INF/lib/third-library-SNAPSHOT.jar\"", "- \"BOOT-INF/lib/first-project-library.jar\"",
+					"- \"BOOT-INF/lib/second-project-library-SNAPSHOT.jar\"");
 		}
 	}
 
@@ -224,9 +225,10 @@ class BootJarTests extends AbstractBootArchiveTests<TestBootJar> {
 		try (JarFile jarFile = new JarFile(createPopulatedJar())) {
 			assertThat(jarFile.getManifest().getMainAttributes().getValue("Spring-Boot-Classpath-Index"))
 					.isEqualTo("BOOT-INF/classpath.idx");
-			assertThat(entryLines(jarFile, "BOOT-INF/classpath.idx")).containsExactly("- \"first-library.jar\"",
-					"- \"second-library.jar\"", "- \"third-library-SNAPSHOT.jar\"", "- \"first-project-library.jar\"",
-					"- \"second-project-library-SNAPSHOT.jar\"");
+			assertThat(entryLines(jarFile, "BOOT-INF/classpath.idx")).containsExactly(
+					"- \"BOOT-INF/lib/first-library.jar\"", "- \"BOOT-INF/lib/second-library.jar\"",
+					"- \"BOOT-INF/lib/third-library-SNAPSHOT.jar\"", "- \"BOOT-INF/lib/first-project-library.jar\"",
+					"- \"BOOT-INF/lib/second-project-library-SNAPSHOT.jar\"");
 		}
 	}
 

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/run/BootRunIntegrationTests.java

@@ -81,7 +81,8 @@ class BootRunIntegrationTests {
 		copyClasspathApplication();
 		BuildResult result = this.gradleBuild.build("echoMainClassName");
 		assertThat(result.task(":echoMainClassName").getOutcome()).isEqualTo(TaskOutcome.SUCCESS);
-		assertThat(result.getOutput()).contains("Main class name = com.example.classpath.BootRunClasspathApplication");
+		assertThat(result.getOutput())
+				.contains("Main class name = com.example.bootrun.classpath.BootRunClasspathApplication");
 	}
 
 	@TestTemplate
@@ -129,9 +130,9 @@ class BootRunIntegrationTests {
 	}
 
 	private void copyApplication(String name) throws IOException {
-		File output = new File(this.gradleBuild.getProjectDir(), "src/main/java/com/example/" + name);
+		File output = new File(this.gradleBuild.getProjectDir(), "src/main/java/com/example/bootrun/" + name);
 		output.mkdirs();
-		FileSystemUtils.copyRecursively(new File("src/test/java/com/example/" + name), output);
+		FileSystemUtils.copyRecursively(new File("src/test/java/com/example/bootrun/" + name), output);
 	}
 
 	private String canonicalPathOf(String path) throws IOException {