Fixed issues with missing classes when running maven plugin

Signed-off-by: Marcin Grzejszczak <[email protected]>

Author: marcingrzejszczak

spring-cloud-contract-stub-runner/src/main/java/org/springframework/cloud/contract/stubrunner/AetherFactories.java

@@ -34,17 +34,29 @@
 import org.eclipse.aether.DefaultRepositorySystemSession;
 import org.eclipse.aether.RepositorySystem;
 import org.eclipse.aether.RepositorySystemSession;
-import org.eclipse.aether.connector.basic.BasicRepositoryConnectorFactory;
 import org.eclipse.aether.impl.DefaultServiceLocator;
 import org.eclipse.aether.repository.LocalRepository;
 import org.eclipse.aether.repository.RepositoryPolicy;
 import org.eclipse.aether.spi.connector.RepositoryConnectorFactory;
 import org.eclipse.aether.spi.connector.transport.TransporterFactory;
-import org.eclipse.aether.transport.file.FileTransporterFactory;
-import org.eclipse.aether.transport.http.HttpTransporterFactory;
 
+import org.springframework.lang.Nullable;
 import org.springframework.util.StringUtils;
 
+/**
+ * Utilities for creating/obtaining Aether (Maven Resolver) components.
+ *
+ * <p>
+ * <b>Key changes vs the old version:</b>
+ * <ul>
+ * <li>No hard reference to {@code BasicRepositoryConnectorFactory} or transporter
+ * implementations. We register them reflectively if present, otherwise we rely on Maven's
+ * injected components or whatever the runtime provides via ServiceLoader.</li>
+ * <li>Supports using Maven-injected {@link RepositorySystem} and
+ * {@link RepositorySystemSession} when called from a Mojo, avoiding classpath issues
+ * entirely.</li>
+ * </ul>
+ */
 final class AetherFactories {
 
 	private static final Log log = LogFactory.getLog(AetherFactories.class);
@@ -61,21 +73,126 @@ private AetherFactories() {
 		throw new IllegalStateException("Can't instantiate a utility class");
 	}
 
-	public static RepositorySystem newRepositorySystem() {
+	/**
+	 * Return the injected system if available, otherwise create a new one via a
+	 * {@link DefaultServiceLocator} without hard-linking to optional providers.
+	 */
+	static RepositorySystem repositorySystemOr(@Nullable RepositorySystem injectedOrNull) {
+		if (injectedOrNull != null) {
+			if (log.isDebugEnabled()) {
+				log.debug("Using Maven-injected RepositorySystem");
+			}
+			return injectedOrNull;
+		}
+		if (log.isDebugEnabled()) {
+			log.debug("No injected RepositorySystem provided; creating one via ServiceLocator");
+		}
+		return newRepositorySystemFallback();
+	}
+
+	/**
+	 * Return the injected session if available, otherwise create a new session for the
+	 * given system.
+	 */
+	static RepositorySystemSession sessionOr(RepositorySystem system, @Nullable RepositorySystemSession injectedOrNull,
+			boolean workOffline) {
+		if (injectedOrNull != null) {
+			if (log.isDebugEnabled()) {
+				log.debug("Using Maven-injected RepositorySystemSession (workOffline=" + injectedOrNull.isOffline()
+						+ ")");
+			}
+			return injectedOrNull;
+		}
+		return newSession(system, workOffline);
+	}
+
+	/**
+	 * Fallback creation using a ServiceLocator. This tries to register common providers
+	 * reflectively:
+	 * <ul>
+	 * <li>org.eclipse.aether.connector.basic.BasicRepositoryConnectorFactory</li>
+	 * <li>org.eclipse.aether.transport.file.FileTransporterFactory</li>
+	 * <li>org.eclipse.aether.transport.http.HttpTransporterFactory</li>
+	 * </ul>
+	 * If any of these are missing on the classpath, we simply don't register them and let
+	 * ServiceLoader discover whatever is available. This avoids
+	 * {@code NoClassDefFoundError} at class load time.
+	 */
+	private static RepositorySystem newRepositorySystemFallback() {
 		DefaultServiceLocator locator = MavenRepositorySystemUtils.newServiceLocator();
-		locator.addService(RepositoryConnectorFactory.class, BasicRepositoryConnectorFactory.class);
-		locator.addService(TransporterFactory.class, FileTransporterFactory.class);
-		locator.addService(TransporterFactory.class, HttpTransporterFactory.class);
-		return locator.getService(RepositorySystem.class);
+
+		// Helpful diagnostics
+		locator.setErrorHandler(new DefaultServiceLocator.ErrorHandler() {
+			@Override
+			public void serviceCreationFailed(Class<?> type, Class<?> impl, Throwable exception) {
+				if (log.isDebugEnabled()) {
+					log.debug("Failed to create service " + type.getName() + " via "
+							+ (impl != null ? impl.getName() : "<null>") + ": " + exception.toString());
+				}
+			}
+		});
+
+		// Try to register connector + transporters reflectively, but do not hard-link
+		// them.
+		registerIfPresent(locator, "org.eclipse.aether.connector.basic.BasicRepositoryConnectorFactory",
+				RepositoryConnectorFactory.class);
+
+		registerIfPresent(locator, "org.eclipse.aether.transport.file.FileTransporterFactory",
+				TransporterFactory.class);
+
+		registerIfPresent(locator, "org.eclipse.aether.transport.http.HttpTransporterFanewRepositorySystemctory",
+				TransporterFactory.class);
+
+		RepositorySystem system = locator.getService(RepositorySystem.class);
+
+		// If system still ended up null, give a helpful hint.
+		if (system == null) {
+			throw new IllegalStateException("Failed to obtain RepositorySystem. "
+					+ "Ensure Maven Resolver is on the classpath and, when running inside a Maven plugin, "
+					+ "prefer using the Maven-injected RepositorySystem/RepositorySystemSession.");
+		}
+		return system;
 	}
 
-	public static RepositorySystemSession newSession(RepositorySystem system, boolean workOffline) {
+	@SuppressWarnings({ "unchecked", "rawtypes" })
+	private static void registerIfPresent(DefaultServiceLocator locator, String implClassName, Class<?> serviceType) {
+		try {
+			ClassLoader cl = Thread.currentThread().getContextClassLoader();
+			if (cl == null) {
+				cl = AetherFactories.class.getClassLoader();
+			}
+			Class<?> impl = Class.forName(implClassName, false, cl);
+			if (!serviceType.isAssignableFrom(impl)) {
+				if (log.isDebugEnabled()) {
+					log.debug("Class " + implClassName + " is not assignable to " + serviceType.getName());
+				}
+				return;
+			}
+			locator.addService((Class) serviceType, (Class) impl);
+			if (log.isDebugEnabled()) {
+				log.debug("Registered " + implClassName + " as " + serviceType.getSimpleName());
+			}
+		}
+		catch (ClassNotFoundException ex) {
+			// Silently skip; not on classpath (e.g., plugin didn't ship connector-basic).
+			if (log.isDebugEnabled()) {
+				log.debug("Optional provider not found on classpath: " + implClassName);
+			}
+		}
+	}
+
+	/**
+	 * Create a new {@link RepositorySystemSession}, controlling offline/update/checksum
+	 * policies.
+	 */
+	static RepositorySystemSession newSession(RepositorySystem system, boolean workOffline) {
 		DefaultRepositorySystemSession session = MavenRepositorySystemUtils.newSession();
 		session.setOffline(workOffline);
 		if (!workOffline) {
 			session.setUpdatePolicy(RepositoryPolicy.UPDATE_POLICY_ALWAYS);
 		}
 		session.setChecksumPolicy(RepositoryPolicy.CHECKSUM_POLICY_WARN);
+
 		String localRepositoryDirectory = localRepositoryDirectory(workOffline);
 		if (log.isDebugEnabled()) {
 			log.debug("Local Repository Directory set to [" + localRepositoryDirectory + "]. Work offline: ["
@@ -86,7 +203,11 @@ public static RepositorySystemSession newSession(RepositorySystem system, boolea
 		return session;
 	}
 
-	protected static String localRepositoryDirectory(boolean workOffline) {
+	/**
+	 * Determine local repo directory: respect settings/system prop; use temp when online
+	 * to avoid pollution.
+	 */
+	static String localRepositoryDirectory(boolean workOffline) {
 		String localRepoLocationFromSettings = settings().getLocalRepository();
 		String currentLocalRepo = readPropertyFromSystemProps(localRepoLocationFromSettings);
 		if (workOffline) {
@@ -101,17 +222,17 @@ private static String temporaryDirectory() {
 		}
 		catch (IOException e) {
 			if (log.isDebugEnabled()) {
-				log.debug("Failed to create a new temporary directory, will generate a new one under temp dir");
+				log.debug("Failed to create a new temporary directory, will generate a new one under temp dir", e);
 			}
 			return System.getProperty("java.io.tmpdir") + File.separator + RANDOM.nextInt();
 		}
 	}
 
-	private static String readPropertyFromSystemProps(String localRepoLocationFromSettings) {
+	private static String readPropertyFromSystemProps(@Nullable String localRepoLocationFromSettings) {
 		String mavenLocalRepo = fromSystemPropOrEnv(MAVEN_LOCAL_REPOSITORY_LOCATION);
 		return StringUtils.hasText(mavenLocalRepo) ? mavenLocalRepo
-				: localRepoLocationFromSettings != null ? localRepoLocationFromSettings
-						: System.getProperty("user.home") + File.separator + ".m2" + File.separator + "repository";
+				: (localRepoLocationFromSettings != null ? localRepoLocationFromSettings
+						: System.getProperty("user.home") + File.separator + ".m2" + File.separator + "repository");
 	}
 
 	// system prop takes precedence over env var
@@ -139,22 +260,21 @@ private static File userSettings() {
 		return new File(user);
 	}
 
-	protected static Settings settings() {
+	static Settings settings() {
 		SettingsBuilder builder = new DefaultSettingsBuilderFactory().newInstance();
 		SettingsBuildingRequest request = new DefaultSettingsBuildingRequest();
 		request.setUserSettingsFile(userSettings());
 		String global = fromSystemPropOrEnv(MAVEN_GLOBAL_SETTINGS_LOCATION);
 		if (global != null) {
 			request.setGlobalSettingsFile(new File(global));
 		}
-		SettingsBuildingResult result;
 		try {
-			result = builder.build(request);
+			SettingsBuildingResult result = builder.build(request);
+			return result.getEffectiveSettings();
 		}
 		catch (SettingsBuildingException ex) {
 			throw new IllegalStateException(ex);
 		}
-		return result.getEffectiveSettings();
 	}
 
 }

spring-cloud-contract-stub-runner/src/main/java/org/springframework/cloud/contract/stubrunner/AetherStubDownloader.java

@@ -47,7 +47,6 @@
 import org.springframework.cloud.contract.stubrunner.spring.StubRunnerProperties;
 import org.springframework.util.StringUtils;
 
-import static org.springframework.cloud.contract.stubrunner.AetherFactories.newRepositorySystem;
 import static org.springframework.cloud.contract.stubrunner.AetherFactories.newSession;
 import static org.springframework.cloud.contract.stubrunner.AetherFactories.settings;
 import static org.springframework.cloud.contract.stubrunner.util.ZipCategory.unzipTo;
@@ -106,7 +105,7 @@ public AetherStubDownloader(StubRunnerOptions stubRunnerOptions) {
 				throw new UnsupportedOperationException(
 						"You can't use Aether downloader when you use classpath to find stubs");
 		}
-		this.repositorySystem = newRepositorySystem();
+		this.repositorySystem = AetherFactories.repositorySystemOr(null);
 		this.workOffline = stubRunnerOptions.stubsMode == StubRunnerProperties.StubsMode.LOCAL;
 		this.session = newSession(this.repositorySystem, this.workOffline);
 		registerShutdownHook();

spring-cloud-contract-stub-runner/src/test/groovy/org/springframework/cloud/contract/stubrunner/AetherStubDownloaderSpec.groovy

@@ -80,7 +80,7 @@ class AetherStubDownloaderSpec extends Specification {
 					ResourceUtils.getFile(ResourceUtils.CLASSPATH_URL_PREFIX + m2repoFolder).getAbsolutePath() + '</localRepository></settings>'
 			System.setProperty("org.apache.maven.user-settings", tempSettings.getAbsolutePath())
 			RepositorySystemSession repositorySystemSession =
-					AetherFactories.newSession(AetherFactories.newRepositorySystem(), true)
+					AetherFactories.newSession(AetherFactories.repositorySystemOr(null), true)
 
 		and:
 			StubRunnerOptions stubRunnerOptions = new StubRunnerOptionsBuilder()

spring-cloud-contract-tools/spring-cloud-contract-maven-plugin/pom.xml

@@ -12,7 +12,7 @@
 	</parent>
 
 	<prerequisites>
-		<maven>3.6</maven>
+		<maven>3.9</maven>
 	</prerequisites>
 
 	<artifactId>spring-cloud-contract-maven-plugin</artifactId>
@@ -41,6 +41,7 @@
 		<maven-plugin-testing-harness.version>4.0.0-beta-4</maven-plugin-testing-harness.version>
 		<maven-shared-incremental.version>1.1</maven-shared-incremental.version>
 		<slf4j-api.version>2.0.7</slf4j-api.version>
+		<plexus-utils.version>3.6.0</plexus-utils.version> <!-- If not set the provided version is 3.0.x and MethodMissing is thrown -->
 	</properties>
 
 	<inceptionYear>2016</inceptionYear>
@@ -293,27 +294,22 @@
 		<dependency>
 			<groupId>org.apache.maven.resolver</groupId>
 			<artifactId>maven-resolver-api</artifactId>
-			<scope>provided</scope>
 		</dependency>
 		<dependency>
 			<groupId>org.apache.maven.resolver</groupId>
 			<artifactId>maven-resolver-impl</artifactId>
-			<scope>provided</scope>
 		</dependency>
 		<dependency>
 			<groupId>org.apache.maven.resolver</groupId>
 			<artifactId>maven-resolver-transport-file</artifactId>
-			<scope>provided</scope>
 		</dependency>
 		<dependency>
 			<groupId>org.apache.maven.resolver</groupId>
 			<artifactId>maven-resolver-transport-http</artifactId>
-			<scope>provided</scope>
 		</dependency>
 		<dependency>
 			<groupId>org.apache.maven.resolver</groupId>
 			<artifactId>maven-resolver-connector-basic</artifactId>
-			<scope>provided</scope>
 		</dependency>
 		<dependency>
 			<groupId>org.apache.maven</groupId>
@@ -333,26 +329,18 @@
 		<dependency>
 			<groupId>org.codehaus.plexus</groupId>
 			<artifactId>plexus-utils</artifactId>
-			<version>4.0.2</version>
+			<version>${plexus-utils.version}</version>
 		</dependency>
-
 		<dependency>
 			<groupId>ch.qos.logback</groupId>
 			<artifactId>logback-core</artifactId>
 		</dependency>
-		<dependency>
-			<groupId>org.slf4j</groupId>
-			<artifactId>slf4j-simple</artifactId>
-			<scope>test</scope>
-		</dependency>
-
 		<dependency>
 			<groupId>org.apache.maven</groupId>
 			<artifactId>maven-core</artifactId>
 			<version>${maven.version}</version>
 			<scope>provided</scope>
 		</dependency>
-
 		<dependency>
 			<groupId>org.apache.maven</groupId>
 			<artifactId>maven-plugin-api</artifactId>
@@ -377,13 +365,12 @@
 			<groupId>org.apache.maven.plugin-tools</groupId>
 			<artifactId>maven-plugin-annotations</artifactId>
 			<version>${maven-plugin-annotations.version}</version>
-			<scope>provided</scope>
 		</dependency>
-
 		<dependency>
 			<groupId>org.apache.maven</groupId>
 			<artifactId>maven-archiver</artifactId>
 			<version>${maven-archiver.version}</version>
+			<scope>provided</scope>
 		</dependency>
 		<dependency>
 			<groupId>org.codehaus.plexus</groupId>
@@ -396,12 +383,18 @@
 			<version>${maven-shared-incremental.version}</version>
 		</dependency>
 
+		<dependency>
+			<groupId>org.slf4j</groupId>
+			<artifactId>slf4j-simple</artifactId>
+			<scope>test</scope>
+		</dependency>
 		<dependency>
 			<groupId>org.apache.maven</groupId>
 			<artifactId>maven-compat</artifactId>
 			<version>${maven.version}</version>
 			<scope>test</scope>
 		</dependency>
+		<!-- TODO: Migrate to junit5 for maven tests -->
 		<dependency>
 			<groupId>junit</groupId>
 			<artifactId>junit</artifactId>