Support generateId method for McpServerSession.Factory

Signed-off-by: JermaineHua <crazyhzm@apache.org>

Author: CrazyHZM

mcp-spring/mcp-spring-webflux/src/main/java/io/modelcontextprotocol/server/transport/WebFluxSseServerTransportProvider.java

@@ -262,7 +262,7 @@ private Mono<ServerResponse> handleSseConnection(ServerRequest request) {
 			.body(Flux.<ServerSentEvent<?>>create(sink -> {
 				WebFluxMcpSessionTransport sessionTransport = new WebFluxMcpSessionTransport(sink);
 
-				String sessionId = UUID.randomUUID().toString();
+				String sessionId = sessionFactory.generateId();
 				McpServerSession session = sessionFactory.create(sessionId, sessionTransport);
 
 				logger.debug("Created new SSE connection for session: {}", sessionId);

mcp-spring/mcp-spring-webmvc/src/main/java/io/modelcontextprotocol/server/transport/WebMvcSseServerTransportProvider.java

@@ -247,7 +247,7 @@ private ServerResponse handleSseConnection(ServerRequest request) {
 			return ServerResponse.status(HttpStatus.SERVICE_UNAVAILABLE).body("Server is shutting down");
 		}
 
-		String sessionId = UUID.randomUUID().toString();
+		String sessionId = sessionFactory.generateId();
 		logger.debug("Creating new SSE connection for session: {}", sessionId);
 
 		// Send initial endpoint event

mcp/src/main/java/io/modelcontextprotocol/server/transport/HttpServletSseServerTransportProvider.java

@@ -208,7 +208,7 @@ protected void doGet(HttpServletRequest request, HttpServletResponse response)
 		response.setHeader("Connection", "keep-alive");
 		response.setHeader("Access-Control-Allow-Origin", "*");
 
-		String sessionId = UUID.randomUUID().toString();
+		String sessionId = sessionFactory.generateId();
 		AsyncContext asyncContext = request.startAsync();
 		asyncContext.setTimeout(0);
 

mcp/src/main/java/io/modelcontextprotocol/server/transport/StdioServerTransportProvider.java

@@ -95,7 +95,7 @@ public StdioServerTransportProvider(ObjectMapper objectMapper, InputStream input
 	public void setSessionFactory(McpServerSession.Factory sessionFactory) {
 		// Create a single session for the stdio connection
 		var transport = new StdioMcpSessionTransport();
-		String sessionId = UUID.randomUUID().toString();
+		String sessionId = sessionFactory.generateId();
 		this.session = sessionFactory.create(sessionId, transport);
 		transport.initProcessing();
 	}

mcp/src/main/java/io/modelcontextprotocol/spec/McpServerSession.java

@@ -2,6 +2,7 @@
 
 import java.time.Duration;
 import java.util.Map;
+import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicLong;
@@ -348,6 +349,14 @@ public interface Factory {
 		 */
 		McpServerSession create(String sessionId, McpServerTransport sessionTransport);
 
+		/**
+		 * Generates a unique session id.
+		 * @return a unique session id.
+		 */
+		default String generateId() {
+			return UUID.randomUUID().toString();
+		}
+
 	}
 
 }

mcp/src/test/java/io/modelcontextprotocol/MockMcpServerTransportProvider.java

@@ -44,7 +44,7 @@ public MockMcpServerTransport getTransport() {
 	@Override
 	public void setSessionFactory(Factory sessionFactory) {
 
-		String sessionId = UUID.randomUUID().toString();
+		String sessionId = sessionFactory.generateId();
 		session = sessionFactory.create(sessionId, transport);
 	}
 

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

@@ -10,6 +10,7 @@
 import java.io.PrintStream;
 import java.nio.charset.StandardCharsets;
 import java.util.Map;
+import java.util.UUID;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;