feat(test): adds findAvailablePort for test server

mcp-spring/mcp-spring-webflux/src/test/java/io/modelcontextprotocol/TestUtil.java

@@ -0,0 +1,31 @@
+/*
+* Copyright 2025 - 2025 the original author or authors.
+*/
+package io.modelcontextprotocol;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.net.ServerSocket;
+
+public class TestUtil {
+
+	TestUtil() {
+		// Prevent instantiation
+	}
+
+	/**
+	 * Finds an available port on the local machine.
+	 * @return an available port number
+	 * @throws IllegalStateException if no available port can be found
+	 */
+	public static int findAvailablePort() {
+		try (final ServerSocket socket = new ServerSocket()) {
+			socket.bind(new InetSocketAddress(0));
+			return socket.getLocalPort();
+		}
+		catch (final IOException e) {
+			throw new IllegalStateException("Cannot bind to an available port!", e);
+		}
+	}
+
+}

mcp-spring/mcp-spring-webflux/src/test/java/io/modelcontextprotocol/WebFluxSseIntegrationTests.java

@@ -50,9 +50,9 @@
 import static org.awaitility.Awaitility.await;
 import static org.mockito.Mockito.mock;
 
-public class WebFluxSseIntegrationTests {
+class WebFluxSseIntegrationTests {
 
-	private static final int PORT = 8182;
+	private static final int PORT = TestUtil.findAvailablePort();
 
 	private static final String CUSTOM_SSE_ENDPOINT = "/somePath/sse";
 
@@ -133,7 +133,7 @@ void testCreateMessageWithoutSamplingCapabilities(String clientType) {
 
 	@ParameterizedTest(name = "{0} : {displayName} ")
 	@ValueSource(strings = { "httpclient", "webflux" })
-	void testCreateMessageSuccess(String clientType) throws InterruptedException {
+	void testCreateMessageSuccess(String clientType) {
 
 		var clientBuilder = clientBuilders.get(clientType);
 
@@ -189,8 +189,7 @@ void testCreateMessageSuccess(String clientType) throws InterruptedException {
 
 			CallToolResult response = mcpClient.callTool(new McpSchema.CallToolRequest("tool1", Map.of()));
 
-			assertThat(response).isNotNull();
-			assertThat(response).isEqualTo(callResponse);
+			assertThat(response).isNotNull().isEqualTo(callResponse);
 		}
 		mcpServer.close();
 	}
@@ -417,8 +416,7 @@ void testToolCallSuccess(String clientType) {
 
 			CallToolResult response = mcpClient.callTool(new McpSchema.CallToolRequest("tool1", Map.of()));
 
-			assertThat(response).isNotNull();
-			assertThat(response).isEqualTo(callResponse);
+			assertThat(response).isNotNull().isEqualTo(callResponse);
 		}
 
 		mcpServer.close();

mcp-spring/mcp-spring-webflux/src/test/java/io/modelcontextprotocol/server/WebFluxSseMcpAsyncServerTests.java

@@ -5,6 +5,8 @@
 package io.modelcontextprotocol.server;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+
+import io.modelcontextprotocol.TestUtil;
 import io.modelcontextprotocol.server.transport.WebFluxSseServerTransportProvider;
 import io.modelcontextprotocol.spec.McpServerTransportProvider;
 import org.junit.jupiter.api.Timeout;
@@ -23,7 +25,7 @@
 @Timeout(15) // Giving extra time beyond the client timeout
 class WebFluxSseMcpAsyncServerTests extends AbstractMcpAsyncServerTests {
 
-	private static final int PORT = 8181;
+	private static final int PORT = TestUtil.findAvailablePort();
 
 	private static final String MESSAGE_ENDPOINT = "/mcp/message";
 

mcp-spring/mcp-spring-webflux/src/test/java/io/modelcontextprotocol/server/WebFluxSseMcpSyncServerTests.java

@@ -5,6 +5,8 @@
 package io.modelcontextprotocol.server;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+
+import io.modelcontextprotocol.TestUtil;
 import io.modelcontextprotocol.server.transport.WebFluxSseServerTransportProvider;
 import io.modelcontextprotocol.spec.McpServerTransportProvider;
 import org.junit.jupiter.api.Timeout;
@@ -23,7 +25,7 @@
 @Timeout(15) // Giving extra time beyond the client timeout
 class WebFluxSseMcpSyncServerTests extends AbstractMcpSyncServerTests {
 
-	private static final int PORT = 8182;
+	private static final int PORT = TestUtil.findAvailablePort();
 
 	private static final String MESSAGE_ENDPOINT = "/mcp/message";
 

mcp-spring/mcp-spring-webmvc/src/test/java/io/modelcontextprotocol/server/TomcatTestUtil.java

@@ -3,6 +3,10 @@
 */
 package io.modelcontextprotocol.server;
 
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.net.ServerSocket;
+
 import org.apache.catalina.Context;
 import org.apache.catalina.startup.Tomcat;
 
@@ -14,10 +18,14 @@
  */
 public class TomcatTestUtil {
 
+	TomcatTestUtil() {
+		// Prevent instantiation
+	}
+
 	public record TomcatServer(Tomcat tomcat, AnnotationConfigWebApplicationContext appContext) {
 	}
 
-	public TomcatServer createTomcatServer(String contextPath, int port, Class<?> componentClass) {
+	public static TomcatServer createTomcatServer(String contextPath, int port, Class<?> componentClass) {
 
 		// Set up Tomcat first
 		var tomcat = new Tomcat();
@@ -57,4 +65,19 @@ public TomcatServer createTomcatServer(String contextPath, int port, Class<?> co
 		return new TomcatServer(tomcat, appContext);
 	}
 
+	/**
+	 * Finds an available port on the local machine.
+	 * @return an available port number
+	 * @throws IllegalStateException if no available port can be found
+	 */
+	public static int findAvailablePort() {
+		try (final ServerSocket socket = new ServerSocket()) {
+			socket.bind(new InetSocketAddress(0));
+			return socket.getLocalPort();
+		}
+		catch (final IOException e) {
+			throw new IllegalStateException("Cannot bind to an available port!", e);
+		}
+	}
+
 }

mcp-spring/mcp-spring-webmvc/src/test/java/io/modelcontextprotocol/server/WebMvcSseAsyncServerTransportTests.java

@@ -25,7 +25,7 @@ class WebMvcSseAsyncServerTransportTests extends AbstractMcpAsyncServerTests {
 
 	private static final String MESSAGE_ENDPOINT = "/mcp/message";
 
-	private static final int PORT = 8181;
+	private static final int PORT = TomcatTestUtil.findAvailablePort();
 
 	private Tomcat tomcat;
 
@@ -73,7 +73,6 @@ protected McpServerTransportProvider createMcpTransportProvider() {
 
 		// Create DispatcherServlet with our Spring context
 		DispatcherServlet dispatcherServlet = new DispatcherServlet(appContext);
-		// dispatcherServlet.setThrowExceptionIfNoHandlerFound(true);
 
 		// Add servlet to Tomcat and get the wrapper
 		var wrapper = Tomcat.addServlet(context, "dispatcherServlet", dispatcherServlet);

mcp-spring/mcp-spring-webmvc/src/test/java/io/modelcontextprotocol/server/WebMvcSseCustomContextPathTests.java

@@ -22,11 +22,11 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
-public class WebMvcSseCustomContextPathTests {
+class WebMvcSseCustomContextPathTests {
 
 	private static final String CUSTOM_CONTEXT_PATH = "/app/1";
 
-	private static final int PORT = 8183;
+	private static final int PORT = TomcatTestUtil.findAvailablePort();
 
 	private static final String MESSAGE_ENDPOINT = "/mcp/message";
 
@@ -39,11 +39,11 @@ public class WebMvcSseCustomContextPathTests {
 	@BeforeEach
 	public void before() {
 
-		tomcatServer = new TomcatTestUtil().createTomcatServer(CUSTOM_CONTEXT_PATH, PORT, TestConfig.class);
+		tomcatServer = TomcatTestUtil.createTomcatServer(CUSTOM_CONTEXT_PATH, PORT, TestConfig.class);
 
 		try {
 			tomcatServer.tomcat().start();
-			assertThat(tomcatServer.tomcat().getServer().getState() == LifecycleState.STARTED);
+			assertThat(tomcatServer.tomcat().getServer().getState()).isEqualTo(LifecycleState.STARTED);
 		}
 		catch (Exception e) {
 			throw new RuntimeException("Failed to start Tomcat", e);

mcp-spring/mcp-spring-webmvc/src/test/java/io/modelcontextprotocol/server/WebMvcSseIntegrationTests.java

@@ -46,7 +46,7 @@
 
 class WebMvcSseIntegrationTests {
 
-	private static final int PORT = 8183;
+	private static final int PORT = TomcatTestUtil.findAvailablePort();
 
 	private static final String MESSAGE_ENDPOINT = "/mcp/message";
 
@@ -75,7 +75,7 @@ public RouterFunction<ServerResponse> routerFunction(WebMvcSseServerTransportPro
 	@BeforeEach
 	public void before() {
 
-		tomcatServer = new TomcatTestUtil().createTomcatServer("", PORT, TestConfig.class);
+		tomcatServer = TomcatTestUtil.createTomcatServer("", PORT, TestConfig.class);
 
 		try {
 			tomcatServer.tomcat().start();
@@ -151,7 +151,7 @@ void testCreateMessageWithoutSamplingCapabilities() {
 	}
 
 	@Test
-	void testCreateMessageSuccess() throws InterruptedException {
+	void testCreateMessageSuccess() {
 
 		Function<CreateMessageRequest, CreateMessageResult> samplingHandler = request -> {
 			assertThat(request.messages()).hasSize(1);

mcp-spring/mcp-spring-webmvc/src/test/java/io/modelcontextprotocol/server/WebMvcSseSyncServerTransportTests.java

@@ -24,7 +24,7 @@ class WebMvcSseSyncServerTransportTests extends AbstractMcpSyncServerTests {
 
 	private static final String MESSAGE_ENDPOINT = "/mcp/message";
 
-	private static final int PORT = 8181;
+	private static final int PORT = TomcatTestUtil.findAvailablePort();
 
 	private Tomcat tomcat;
 
@@ -72,7 +72,6 @@ protected WebMvcSseServerTransportProvider createMcpTransportProvider() {
 
 		// Create DispatcherServlet with our Spring context
 		DispatcherServlet dispatcherServlet = new DispatcherServlet(appContext);
-		// dispatcherServlet.setThrowExceptionIfNoHandlerFound(true);
 
 		// Add servlet to Tomcat and get the wrapper
 		var wrapper = Tomcat.addServlet(context, "dispatcherServlet", dispatcherServlet);

mcp/src/test/java/io/modelcontextprotocol/server/transport/HttpServletSseServerCustomContextPathTests.java

@@ -4,6 +4,7 @@
 package io.modelcontextprotocol.server.transport;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+
 import io.modelcontextprotocol.client.McpClient;
 import io.modelcontextprotocol.client.transport.HttpClientSseClientTransport;
 import io.modelcontextprotocol.server.McpServer;
@@ -17,9 +18,9 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
-public class HttpServletSseServerCustomContextPathTests {
+class HttpServletSseServerCustomContextPathTests {
 
-	private static final int PORT = 8195;
+	private static final int PORT = TomcatTestUtil.findAvailablePort();
 
 	private static final String CUSTOM_CONTEXT_PATH = "/api/v1";
 
@@ -48,7 +49,7 @@ public void before() {
 
 		try {
 			tomcat.start();
-			assertThat(tomcat.getServer().getState() == LifecycleState.STARTED);
+			assertThat(tomcat.getServer().getState()).isEqualTo(LifecycleState.STARTED);
 		}
 		catch (Exception e) {
 			throw new RuntimeException("Failed to start Tomcat", e);

mcp/src/test/java/io/modelcontextprotocol/server/transport/HttpServletSseServerTransportProviderIntegrationTests.java

@@ -11,6 +11,7 @@
 import java.util.function.Function;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+
 import io.modelcontextprotocol.client.McpClient;
 import io.modelcontextprotocol.client.transport.HttpClientSseClientTransport;
 import io.modelcontextprotocol.server.McpServer;
@@ -43,9 +44,9 @@
 import static org.awaitility.Awaitility.await;
 import static org.mockito.Mockito.mock;
 
-public class HttpServletSseServerTransportProviderIntegrationTests {
+class HttpServletSseServerTransportProviderIntegrationTests {
 
-	private static final int PORT = 8189;
+	private static final int PORT = TomcatTestUtil.findAvailablePort();
 
 	private static final String CUSTOM_SSE_ENDPOINT = "/somePath/sse";
 
@@ -69,7 +70,7 @@ public void before() {
 		tomcat = TomcatTestUtil.createTomcatServer("", PORT, mcpServerTransportProvider);
 		try {
 			tomcat.start();
-			assertThat(tomcat.getServer().getState() == LifecycleState.STARTED);
+			assertThat(tomcat.getServer().getState()).isEqualTo(LifecycleState.STARTED);
 		}
 		catch (Exception e) {
 			throw new RuntimeException("Failed to start Tomcat", e);
@@ -132,7 +133,7 @@ void testCreateMessageWithoutSamplingCapabilities() {
 	}
 
 	@Test
-	void testCreateMessageSuccess() throws InterruptedException {
+	void testCreateMessageSuccess() {
 
 		Function<CreateMessageRequest, CreateMessageResult> samplingHandler = request -> {
 			assertThat(request.messages()).hasSize(1);
@@ -186,8 +187,7 @@ void testCreateMessageSuccess() throws InterruptedException {
 
 			CallToolResult response = mcpClient.callTool(new McpSchema.CallToolRequest("tool1", Map.of()));
 
-			assertThat(response).isNotNull();
-			assertThat(response).isEqualTo(callResponse);
+			assertThat(response).isNotNull().isEqualTo(callResponse);
 		}
 		mcpServer.close();
 	}
@@ -391,8 +391,7 @@ void testToolCallSuccess() {
 
 			CallToolResult response = mcpClient.callTool(new McpSchema.CallToolRequest("tool1", Map.of()));
 
-			assertThat(response).isNotNull();
-			assertThat(response).isEqualTo(callResponse);
+			assertThat(response).isNotNull().isEqualTo(callResponse);
 		}
 
 		mcpServer.close();

mcp/src/test/java/io/modelcontextprotocol/server/transport/TomcatTestUtil.java

@@ -3,19 +3,23 @@
 */
 package io.modelcontextprotocol.server.transport;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.net.ServerSocket;
+
 import jakarta.servlet.Servlet;
 import org.apache.catalina.Context;
-import org.apache.catalina.LifecycleState;
 import org.apache.catalina.startup.Tomcat;
 
-import static org.junit.Assert.assertThat;
-
 /**
  * @author Christian Tzolov
  */
 public class TomcatTestUtil {
 
+	TomcatTestUtil() {
+		// Prevent instantiation
+	}
+
 	public static Tomcat createTomcatServer(String contextPath, int port, Servlet servlet) {
 
 		var tomcat = new Tomcat();
@@ -24,7 +28,6 @@ public static Tomcat createTomcatServer(String contextPath, int port, Servlet se
 		String baseDir = System.getProperty("java.io.tmpdir");
 		tomcat.setBaseDir(baseDir);
 
-		// Context context = tomcat.addContext("", baseDir);
 		Context context = tomcat.addContext(contextPath, baseDir);
 
 		// Add transport servlet to Tomcat
@@ -42,4 +45,19 @@ public static Tomcat createTomcatServer(String contextPath, int port, Servlet se
 		return tomcat;
 	}
 
+	/**
+	 * Finds an available port on the local machine.
+	 * @return an available port number
+	 * @throws IllegalStateException if no available port can be found
+	 */
+	public static int findAvailablePort() {
+		try (final ServerSocket socket = new ServerSocket()) {
+			socket.bind(new InetSocketAddress(0));
+			return socket.getLocalPort();
+		}
+		catch (final IOException e) {
+			throw new IllegalStateException("Cannot bind to an available port!", e);
+		}
+	}
+
 }