Fix Maven-based AOT generation on Windows

Closes gh-30525

Author: wilkinsona

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

@@ -30,6 +30,7 @@
  * Integration tests for the Maven plugin's AOT support.
  *
  * @author Stephane Nicoll
+ * @author Andy Wilkinson
  */
 @ExtendWith(MavenBuildExtension.class)
 public class AotGenerateTests {
@@ -38,39 +39,42 @@ public class AotGenerateTests {
 	void whenAotRunsSourcesAreGenerated(MavenBuild mavenBuild) {
 		mavenBuild.project("aot").goals("package").execute((project) -> {
 			Path aotDirectory = project.toPath().resolve("target/spring-aot/main");
-			assertThat(collectRelativeFileNames(aotDirectory.resolve("sources")))
-					.contains("org/test/SampleApplication__ApplicationContextInitializer.java");
-			assertThat(collectRelativeFileNames(aotDirectory.resolve("resources"))).containsOnly(
-					"META-INF/native-image/org.springframework.boot.maven.it/aot/reflect-config.json",
-					"META-INF/native-image/org.springframework.boot.maven.it/aot/resource-config.json",
-					"META-INF/native-image/org.springframework.boot.maven.it/aot/native-image.properties");
+			assertThat(collectRelativePaths(aotDirectory.resolve("sources")))
+					.contains(Path.of("org", "test", "SampleApplication__ApplicationContextInitializer.java"));
+			assertThat(collectRelativePaths(aotDirectory.resolve("resources"))).containsOnly(
+					Path.of("META-INF", "native-image", "org.springframework.boot.maven.it", "aot",
+							"reflect-config.json"),
+					Path.of("META-INF", "native-image", "org.springframework.boot.maven.it", "aot",
+							"resource-config.json"),
+					Path.of("META-INF", "native-image", "org.springframework.boot.maven.it", "aot",
+							"native-image.properties"));
 		});
 	}
 
 	@TestTemplate
 	void whenAotRunsSourcesAreCompiled(MavenBuild mavenBuild) {
 		mavenBuild.project("aot").goals("package").execute((project) -> {
 			Path classesDirectory = project.toPath().resolve("target/classes");
-			assertThat(collectRelativeFileNames(classesDirectory))
-					.contains("org/test/SampleApplication__ApplicationContextInitializer.class");
+			assertThat(collectRelativePaths(classesDirectory))
+					.contains(Path.of("org", "test", "SampleApplication__ApplicationContextInitializer.class"));
 		});
 	}
 
 	@TestTemplate
 	void whenAotRunsResourcesAreCopiedToTargetClasses(MavenBuild mavenBuild) {
 		mavenBuild.project("aot").goals("package").execute((project) -> {
 			Path classesDirectory = project.toPath().resolve("target/classes/META-INF/native-image");
-			assertThat(collectRelativeFileNames(classesDirectory)).contains(
-					"org.springframework.boot.maven.it/aot/reflect-config.json",
-					"org.springframework.boot.maven.it/aot/resource-config.json",
-					"org.springframework.boot.maven.it/aot/native-image.properties");
+			assertThat(collectRelativePaths(classesDirectory)).contains(
+					Path.of("org.springframework.boot.maven.it", "aot", "reflect-config.json"),
+					Path.of("org.springframework.boot.maven.it", "aot", "resource-config.json"),
+					Path.of("org.springframework.boot.maven.it", "aot", "native-image.properties"));
 		});
 	}
 
-	Stream<String> collectRelativeFileNames(Path sourceDirectory) {
+	Stream<Path> collectRelativePaths(Path sourceDirectory) {
 		try {
 			return Files.walk(sourceDirectory).filter(Files::isRegularFile)
-					.map((path) -> path.subpath(sourceDirectory.getNameCount(), path.getNameCount()).toString());
+					.map((path) -> path.subpath(sourceDirectory.getNameCount(), path.getNameCount()));
 		}
 		catch (IOException ex) {
 			throw new IllegalStateException(ex);

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/AotGenerateMojo.java

@@ -23,11 +23,9 @@
 import java.nio.file.Path;
 import java.nio.file.StandardCopyOption;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
-import java.util.stream.Collectors;
 
 import javax.tools.Diagnostic;
 import javax.tools.DiagnosticListener;
@@ -83,7 +81,7 @@ protected void run(File workingDirectory, String startClassName, Map<String, Str
 			throws MojoExecutionException, MojoFailureException {
 		try {
 			generateAotAssets(workingDirectory, startClassName, environmentVariables);
-			compileSourceFiles(getClassPathUrls());
+			compileSourceFiles();
 			copyNativeConfiguration(this.generatedResources.toPath());
 		}
 		catch (Exception ex) {
@@ -139,16 +137,17 @@ protected URL[] getClassPathUrls() throws MojoExecutionException {
 		}
 	}
 
-	private void compileSourceFiles(URL[] classpathUrls) throws IOException {
+	private void compileSourceFiles() throws IOException, MojoExecutionException {
 		List<Path> sourceFiles = Files.walk(this.generatedSources.toPath()).filter(Files::isRegularFile).toList();
 		if (sourceFiles.isEmpty()) {
 			return;
 		}
 		JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
 		try (StandardJavaFileManager fm = compiler.getStandardFileManager(null, null, null)) {
-			List<String> options = List.of("-cp",
-					Arrays.stream(classpathUrls).map(URL::toString).collect(Collectors.joining(File.pathSeparator)),
-					"-d", this.classesDirectory.toPath().toAbsolutePath().toString());
+			List<String> options = new ArrayList<>();
+			addClasspath(options);
+			options.add("-d");
+			options.add(this.classesDirectory.toPath().toAbsolutePath().toString());
 			Iterable<? extends JavaFileObject> compilationUnits = fm.getJavaFileObjectsFromPaths(sourceFiles);
 			Errors errors = new Errors();
 			CompilationTask task = compiler.getTask(null, fm, errors, options, null, compilationUnits);