From 3f0fd7a004fe1d88f8a4348b05bb17e6eae12901 Mon Sep 17 00:00:00 2001
From: Marcin Grzejszczak <mgrzejszczak@vmware.com>
Date: Mon, 21 Nov 2022 18:32:32 +0100
Subject: [PATCH] Fixes java contract runtime compilation; fixes gh-1849

---
 docs/pom.xml                                  |  2 +-
 samples/standalone/dsl/http-server/pom.xml    | 43 ++++++++++++++++
 .../util/ContractVerifierDslConverter.java    | 51 ++++++++++++++++---
 3 files changed, 88 insertions(+), 8 deletions(-)

diff --git a/docs/pom.xml b/docs/pom.xml
index cacfde52de..969d2b0d46 100644
--- a/docs/pom.xml
+++ b/docs/pom.xml
@@ -21,7 +21,7 @@
 		<configprops.inclusionPattern>stubrunner.*|wiremock.*|</configprops.inclusionPattern>
 		<upload-docs-zip.phase>deploy</upload-docs-zip.phase>
 		<!-- Aligned with Groovy in SC-Build -->
-		<groovy.version>4.0.0</groovy.version>
+		<groovy.version>4.0.6</groovy.version>
 	</properties>
 	<build>
 		<plugins>
diff --git a/samples/standalone/dsl/http-server/pom.xml b/samples/standalone/dsl/http-server/pom.xml
index 2f9d221416..d07b9d3d8c 100644
--- a/samples/standalone/dsl/http-server/pom.xml
+++ b/samples/standalone/dsl/http-server/pom.xml
@@ -138,6 +138,49 @@
 					<failIfNoTests>true</failIfNoTests>
 				</configuration>
 			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-antrun-plugin</artifactId>
+				<version>3.1.0</version>
+				<executions>
+					<execution>
+						<phase>process-test-resources</phase>
+						<configuration>
+							<target>
+								<taskdef resource="net/sf/antcontrib/antcontrib.properties" />
+								<fail message="Generated test files are missing.">
+									<condition>
+										<not>
+											<resourcecount count="6">
+												<fileset id="fs" dir="${project.build.directory}/generated-test-sources/contracts/com/example/fraud/" includes="BinaryTest.java,FraudnameTest.java,FraudTest.java,MessagingTest.java,MultipartTest.java,TestTest.java"/>
+											</resourcecount>
+										</not>
+									</condition>
+								</fail>
+								<fail message="Generated test files are missing.">
+									<condition>
+										<not>
+											<resourcecount count="2">
+												<fileset id="fs" dir="${project.build.directory}/generated-test-sources/contracts/com/example/fraud/yml" includes="FraudnameTest.java,FraudTest.java"/>
+											</resourcecount>
+										</not>
+									</condition>
+								</fail>
+							</target>
+						</configuration>
+						<goals>
+							<goal>run</goal>
+						</goals>
+					</execution>
+				</executions>
+				<dependencies>
+					<dependency>
+						<groupId>ant-contrib</groupId>
+						<artifactId>ant-contrib</artifactId>
+						<version>20020829</version>
+					</dependency>
+				</dependencies>
+			</plugin>
 		</plugins>
 		<pluginManagement>
 			<plugins>
diff --git a/spring-cloud-contract-verifier/src/main/java/org/springframework/cloud/contract/verifier/util/ContractVerifierDslConverter.java b/spring-cloud-contract-verifier/src/main/java/org/springframework/cloud/contract/verifier/util/ContractVerifierDslConverter.java
index f3a5db19b6..856f03b931 100644
--- a/spring-cloud-contract-verifier/src/main/java/org/springframework/cloud/contract/verifier/util/ContractVerifierDslConverter.java
+++ b/spring-cloud-contract-verifier/src/main/java/org/springframework/cloud/contract/verifier/util/ContractVerifierDslConverter.java
@@ -26,10 +26,13 @@ import java.net.URLClassLoader;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
+import java.util.Set;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Supplier;
 import java.util.regex.Matcher;
@@ -52,6 +55,7 @@ import org.springframework.cloud.contract.spec.Contract;
 import org.springframework.cloud.contract.spec.ContractConverter;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.ObjectUtils;
+import org.springframework.util.StringUtils;
 
 /**
  * Converts a String or a Groovy or Java file into a {@link Contract}.
@@ -140,7 +144,7 @@ public class ContractVerifierDslConverter implements ContractConverter<Collectio
 	private static Object toObject(ClassLoader cl, File rootFolder, File dsl) throws IOException {
 		if (isJava(dsl)) {
 			try {
-				return parseJavaFile(dsl);
+				return parseJavaFile(rootFolder, dsl);
 			}
 			catch (Exception ex) {
 				if (LOG.isWarnEnabled()) {
@@ -153,9 +157,9 @@ public class ContractVerifierDslConverter implements ContractConverter<Collectio
 		return groovyShell(cl, rootFolder).evaluate(dsl);
 	}
 
-	private static Object parseJavaFile(File dsl) throws IllegalAccessException, InvocationTargetException,
-			InstantiationException, IOException, NoSuchMethodException {
-		Constructor<?> constructor = classConstructor(dsl);
+	private static Object parseJavaFile(File rootFolder, File dsl) throws IllegalAccessException,
+			InvocationTargetException, InstantiationException, IOException, NoSuchMethodException {
+		Constructor<?> constructor = classConstructor(rootFolder, dsl);
 		Object newInstance = constructor.newInstance();
 		if (!(newInstance instanceof Supplier)) {
 			if (LOG.isDebugEnabled()) {
@@ -167,7 +171,7 @@ public class ContractVerifierDslConverter implements ContractConverter<Collectio
 		return supplier.get();
 	}
 
-	private static Constructor<?> classConstructor(File dsl)
+	private static Constructor<?> classConstructor(File rootFolder, File dsl)
 			throws IllegalAccessException, IOException, NoSuchMethodException {
 		try (StandardJavaFileManager fileManager = COMPILER.getStandardFileManager(null, null, null)) {
 			try (Stream<String> lines = Files.lines(Paths.get(dsl.getAbsolutePath()))) {
@@ -175,6 +179,15 @@ public class ContractVerifierDslConverter implements ContractConverter<Collectio
 				String fqn = fqn(classText);
 				Path directory = Files.createTempDirectory(fqn);
 				fileManager.setLocation(StandardLocation.CLASS_OUTPUT, List.of(directory.toFile()));
+				// set compiler's classpath to be same as the runtime's
+				Set<File> classpathLocations = new HashSet<>();
+				classpathLocations.add(rootFolder);
+				appendUrlsFromAllClassLoaders(classpathLocations);
+				String classPath = System.getProperty("java.class.path", "");
+				if (StringUtils.hasText(classPath)) {
+					classpathLocations.addAll(Arrays.stream(classPath.split(":")).map(File::new).toList());
+				}
+				fileManager.setLocation(StandardLocation.CLASS_PATH, classpathLocations);
 				// Compile the file
 				DiagnosticCollector<Object> diagnostics = new DiagnosticCollector<>();
 				JavaCompiler.CompilationTask task = COMPILER.getTask(null, fileManager, diagnostics, null, null,
@@ -183,12 +196,16 @@ public class ContractVerifierDslConverter implements ContractConverter<Collectio
 				if (!success) {
 					throw new IllegalStateException("Exceptions occurred while trying to compile the file \n"
 							+ diagnostics.getDiagnostics().stream()
-									.map(d -> "Error " + d.getMessage(Locale.getDefault()) + "on line "
+									.map(d -> "Error " + d.getMessage(Locale.getDefault()) + " on line "
 											+ d.getLineNumber() + " in " + d.getSource())
 									.collect(Collectors.joining("\n")));
 				}
 				try {
-					Class<?> clazz = ClassUtils.forName(fqn, null);
+					// Add the folder with compiled classes to the class loader
+					URLClassLoader urlClassLoader = new URLClassLoader("contract-classloader",
+							new URL[] { new URL("file://" + directory.toAbsolutePath() + "/") },
+							Thread.currentThread().getContextClassLoader());
+					Class<?> clazz = ClassUtils.forName(fqn, urlClassLoader);
 					Constructor<?> constructor = clazz.getDeclaredConstructor();
 					constructor.setAccessible(true);
 					return constructor;
@@ -200,6 +217,26 @@ public class ContractVerifierDslConverter implements ContractConverter<Collectio
 		}
 	}
 
+	private static void appendUrlsFromAllClassLoaders(Set<File> files) {
+		ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
+		if (classLoader != null) {
+			appendUrlsFromClasspath(files, classLoader);
+			while (classLoader.getParent() != null) {
+				classLoader = classLoader.getParent();
+				appendUrlsFromClasspath(files, classLoader);
+			}
+		}
+	}
+
+	private static void appendUrlsFromClasspath(Set<File> files, ClassLoader classLoader) {
+		if (classLoader instanceof URLClassLoader urlClassLoader) {
+			URL[] urLs = urlClassLoader.getURLs();
+			if (urLs.length > 0) {
+				Arrays.stream(urLs).forEach(url -> files.add(new File(url.getFile())));
+			}
+		}
+	}
+
 	private static boolean isJava(File dsl) {
 		return dsl.getName().endsWith(".java");
 	}