Add option for the resolver and module-launcher to operate in offline mode

spring-cloud-stream-module-launcher/src/main/java/org/springframework/cloud/stream/module/launcher/ModuleLauncherConfiguration.java

@@ -53,7 +53,9 @@ public class ModuleLauncherConfiguration {
 		for (String repository: properties.getRemoteRepositories()) {
 			repositoriesMap.put("repository " + i++, repository);
 		}
-		return new AetherModuleResolver(properties.getLocalRepository(), repositoriesMap);
+		AetherModuleResolver aetherModuleResolver = new AetherModuleResolver(properties.getLocalRepository(), repositoriesMap);
+		aetherModuleResolver.setOffline(properties.isOffline());
+		return aetherModuleResolver;
 	}
 
 	@Bean

spring-cloud-stream-module-launcher/src/main/java/org/springframework/cloud/stream/module/resolver/AetherModuleResolver.java

@@ -68,6 +68,8 @@ public class AetherModuleResolver implements ModuleResolver {
 
 	private final RepositorySystem repositorySystem;
 
+	private volatile boolean offline = false;
+
 	/**
 	 * Create an instance specifying the locations of the local and remote repositories.
 	 * @param localRepository the root path of the local maven repository
@@ -99,6 +101,10 @@ public class AetherModuleResolver implements ModuleResolver {
 		repositorySystem = newRepositorySystem();
 	}
 
+	public void setOffline(boolean offline) {
+		this.offline = offline;
+	}
+
 	/**
 	 * Resolve an artifact and return its location in the local repository. Aether performs the normal
 	 * Maven resolution process ensuring that the latest update is cached to the local repository.
@@ -107,8 +113,8 @@ public class AetherModuleResolver implements ModuleResolver {
 	 * @param extension the file extension
 	 * @param classifier classifier can be null if none
 	 * @param version the version
-	 * @return a {@ link FileSystemResource} representing the resolved artifact in the local repository
-	 * @throws a RuntimeException if the artifact does not exist or the resolution fails
+	 * @return a {@link FileSystemResource} representing the resolved artifact in the local repository
+	 * @throws RuntimeException if the artifact does not exist or the resolution fails
 	 */
 	@Override
 	public Resource resolve(String groupId, String artifactId, String extension, String classifier, String version) {
@@ -141,6 +147,7 @@ public class AetherModuleResolver implements ModuleResolver {
 		DefaultRepositorySystemSession session = MavenRepositorySystemUtils.newSession();
 		LocalRepository localRepo = new LocalRepository(localRepoPath);
 		session.setLocalRepositoryManager(system.newLocalRepositoryManager(session, localRepo));
+		session.setOffline(this.offline);
 		return session;
 	}
 

spring-cloud-stream-module-launcher/src/main/java/org/springframework/cloud/stream/module/resolver/ModuleResolverProperties.java

@@ -39,6 +39,11 @@ public class ModuleResolverProperties {
 	 */
 	private String[] remoteRepositories = new String[] {"https://repo.spring.io/libs-snapshot"};
 
+	/**
+	 * Whether the resolver should operate in offline mode.
+	 */
+	private boolean offline = false;
+
 	public void setRemoteRepositories(String[] remoteRepositories) {
 		this.remoteRepositories = remoteRepositories;
 	}
@@ -54,4 +59,11 @@ public class ModuleResolverProperties {
 		return localRepository;
 	}
 
+	public boolean isOffline() {
+		return offline;
+	}
+
+	public void setOffline(boolean offline) {
+		this.offline = offline;
+	}
 }

spring-cloud-stream-module-launcher/src/test/java/org/springframework/cloud/stream/module/resolver/AetherModuleResolverTests.java

@@ -20,23 +20,31 @@ import static com.github.tomakehurst.wiremock.client.WireMock.aResponse;
 import static com.github.tomakehurst.wiremock.client.WireMock.get;
 import static com.github.tomakehurst.wiremock.client.WireMock.stubFor;
 import static com.github.tomakehurst.wiremock.client.WireMock.urlEqualTo;
+import static org.hamcrest.Matchers.instanceOf;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.file.Files;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.UUID;
 
+import org.eclipse.aether.resolution.ArtifactResolutionException;
+import org.hamcrest.Matchers;
 import org.junit.Ignore;
 import org.junit.Rule;
 import org.junit.Test;
 
 import org.springframework.core.io.ClassPathResource;
+import org.springframework.core.io.FileSystemResource;
 import org.springframework.core.io.Resource;
 import org.springframework.util.SocketUtils;
 
 import com.github.tomakehurst.wiremock.junit.WireMockRule;
+import wiremock.org.mortbay.resource.FileResource;
 
 /**
  * @author David Turanski
@@ -69,8 +77,8 @@ public class AetherModuleResolverTests {
 	@Test
 	@Ignore
 	public void testResolveRemote() throws IOException {
-		ClassPathResource cpr = new ClassPathResource("local-repo");
-		File localRepository = cpr.getFile();
+		File localRepository = Files.createTempDirectory(UUID.randomUUID().toString()).toFile();
+		localRepository.deleteOnExit();
 		Map<String, String> remoteRepos = new HashMap<>();
 		remoteRepos.put("modules", "http://repo.spring.io/libs-snapshot");
 		AetherModuleResolver defaultModuleResolver = new AetherModuleResolver(localRepository, remoteRepos);
@@ -82,8 +90,8 @@ public class AetherModuleResolverTests {
 
 	@Test
 	public void testResolveMockRemote() throws IOException {
-		ClassPathResource cpr = new ClassPathResource("local-repo");
-		File localRepository = cpr.getFile();
+		File localRepository = Files.createTempDirectory(UUID.randomUUID().toString()).toFile();
+		localRepository.deleteOnExit();
 		ClassPathResource stubJarResource = new ClassPathResource("__files/foo.jar");
 		String stubFileName = stubJarResource.getFile().getName();
 		Map<String, String> remoteRepos = new HashMap<>();
@@ -98,4 +106,27 @@ public class AetherModuleResolverTests {
 		assertTrue(resource.exists());
 		assertEquals(resource.getFile().getName(), "foo-1.0.0.jar");
 	}
+
+	@Test
+	public void testResolveOfflineWithMockRemote() throws IOException {
+		try {
+			File localRepository = Files.createTempDirectory(UUID.randomUUID().toString()).toFile();
+			localRepository.deleteOnExit();
+			ClassPathResource stubJarResource = new ClassPathResource("__files/foo.jar");
+			String stubFileName = stubJarResource.getFile().getName();
+			Map<String, String> remoteRepos = new HashMap<>();
+			remoteRepos.put("repo0", "http://localhost:" + port + "/repo0");
+			remoteRepos.put("repo1", "http://localhost:" + port + "/repo1");
+			stubFor(get(urlEqualTo("/repo1/org/bar/foo/1.0.0/foo-1.0.0.jar"))
+					.willReturn(aResponse()
+							.withStatus(200)
+							.withBodyFile(stubFileName)));
+			AetherModuleResolver defaultModuleResolver = new AetherModuleResolver(localRepository, remoteRepos);
+			defaultModuleResolver.setOffline(true);
+			defaultModuleResolver.resolve("org.bar", "foo", "jar", "", "1.0.0");
+		} catch (RuntimeException e) {
+			// remote resolution fails because the resolver is operating offline
+			assertThat(e.getCause(), instanceOf(ArtifactResolutionException.class));
+		}
+	}
 }