chore: Add AsyncCloseable interface.

Signed-off-by: He-Pin <[email protected]>

Author: He-Pin

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

@@ -369,12 +369,6 @@ public <T> T unmarshalFrom(Object data, TypeReference<T> typeRef) {
 		public Mono<Void> closeGracefully() {
 			return Mono.fromRunnable(sink::complete);
 		}
-
-		@Override
-		public void close() {
-			sink.complete();
-		}
-
 	}
 
 	public static Builder builder() {

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

@@ -401,20 +401,6 @@ public Mono<Void> closeGracefully() {
 			});
 		}
 
-		/**
-		 * Closes the transport immediately.
-		 */
-		@Override
-		public void close() {
-			try {
-				sseBuilder.complete();
-				logger.debug("Successfully completed SSE builder for session {}", sessionId);
-			}
-			catch (Exception e) {
-				logger.warn("Failed to complete SSE builder for session {}: {}", sessionId, e.getMessage());
-			}
-		}
-
 	}
 
 }

Diff for: mcp/src/main/java/io/modelcontextprotocol/client/McpAsyncClient.java

@@ -287,13 +287,6 @@ public McpSchema.Implementation getClientInfo() {
 		return this.clientInfo;
 	}
 
-	/**
-	 * Closes the client connection immediately.
-	 */
-	public void close() {
-		this.mcpSession.close();
-	}
-
 	/**
 	 * Gracefully closes the client connection.
 	 * @return A Mono that completes when the connection is closed

Diff for: mcp/src/main/java/io/modelcontextprotocol/client/McpSyncClient.java

@@ -115,7 +115,7 @@ public McpSchema.Implementation getClientInfo() {
 
 	@Override
 	public void close() {
-		this.delegate.close();
+		this.closeGracefully();
 	}
 
 	public boolean closeGracefully() {

Diff for: mcp/src/main/java/io/modelcontextprotocol/server/McpAsyncServer.java

@@ -390,11 +390,6 @@ public Mono<Void> closeGracefully() {
 			return this.mcpTransportProvider.closeGracefully();
 		}
 
-		@Override
-		public void close() {
-			this.mcpTransportProvider.close();
-		}
-
 		private McpServerSession.NotificationHandler asyncRootsListChangedNotificationHandler(
 				List<BiFunction<McpAsyncServerExchange, List<McpSchema.Root>, Mono<Void>>> rootsChangeConsumers) {
 			return (exchange, params) -> exchange.listRoots()

Diff for: mcp/src/main/java/io/modelcontextprotocol/server/transport/HttpServletSseServerTransportProvider.java

@@ -432,22 +432,6 @@ public Mono<Void> closeGracefully() {
 				}
 			});
 		}
-
-		/**
-		 * Closes the transport immediately.
-		 */
-		@Override
-		public void close() {
-			try {
-				sessions.remove(sessionId);
-				asyncContext.complete();
-				logger.debug("Successfully completed async context for session {}", sessionId);
-			}
-			catch (Exception e) {
-				logger.warn("Failed to complete async context for session {}: {}", sessionId, e.getMessage());
-			}
-		}
-
 	}
 
 	/**

Diff for: mcp/src/main/java/io/modelcontextprotocol/server/transport/StdioServerTransportProvider.java

@@ -173,12 +173,6 @@ public Mono<Void> closeGracefully() {
 			});
 		}
 
-		@Override
-		public void close() {
-			isClosing.set(true);
-			logger.debug("Session transport closed");
-		}
-
 		private void initProcessing() {
 			handleIncomingMessages();
 			startInboundProcessing();
@@ -239,7 +233,7 @@ private void startInboundProcessing() {
 					finally {
 						isClosing.set(true);
 						if (session != null) {
-							session.close();
+							session.closeGracefully().block();
 						}
 						inboundSink.tryEmitComplete();
 					}

Diff for: mcp/src/main/java/io/modelcontextprotocol/spec/AsyncCloseable.java

@@ -0,0 +1,15 @@
+package io.modelcontextprotocol.spec;
+
+import reactor.core.publisher.Mono;
+
+/**
+ * Interface for close operations that are asynchronous.
+ */
+public interface AsyncCloseable {
+
+	/**
+	 * Begins the process of closing the resource gracefully.
+	 * @return A {@link Mono} that completes when the resource has been closed.
+	 */
+	Mono<Void> closeGracefully();
+}

Diff for: mcp/src/main/java/io/modelcontextprotocol/spec/McpClientSession.java

@@ -276,14 +276,4 @@ public Mono<Void> closeGracefully() {
 			return transport.closeGracefully();
 		});
 	}
-
-	/**
-	 * Closes the session immediately, potentially interrupting pending operations.
-	 */
-	@Override
-	public void close() {
-		this.connection.dispose();
-		transport.close();
-	}
-
 }

Diff for: mcp/src/main/java/io/modelcontextprotocol/spec/McpServerSession.java

@@ -272,11 +272,6 @@ public Mono<Void> closeGracefully() {
 		return this.transport.closeGracefully();
 	}
 
-	@Override
-	public void close() {
-		this.transport.close();
-	}
-
 	/**
 	 * Request handler for the initialization request.
 	 */

Diff for: mcp/src/main/java/io/modelcontextprotocol/spec/McpServerTransportProvider.java

@@ -29,7 +29,7 @@
  *
  * @author Dariusz Jędrzejczyk
  */
-public interface McpServerTransportProvider {
+public interface McpServerTransportProvider extends AsyncCloseable {
 
 	/**
 	 * Sets the session factory that will be used to create sessions for new clients. An
@@ -48,19 +48,12 @@ public interface McpServerTransportProvider {
 	 */
 	Mono<Void> notifyClients(String method, Object params);
 
-	/**
-	 * Immediately closes all the transports with connected clients and releases any
-	 * associated resources.
-	 */
-	default void close() {
-		this.closeGracefully().subscribe();
-	}
-
 	/**
 	 * Gracefully closes all the transports with connected clients and releases any
 	 * associated resources asynchronously.
 	 * @return a {@link Mono<Void>} that completes when the connections have been closed.
 	 */
+	@Override
 	Mono<Void> closeGracefully();
 
 }

Diff for: mcp/src/main/java/io/modelcontextprotocol/spec/McpSession.java

@@ -23,7 +23,7 @@
  * @author Christian Tzolov
  * @author Dariusz Jędrzejczyk
  */
-public interface McpSession {
+public interface McpSession extends AsyncCloseable {
 
 	/**
 	 * Sends a request to the model counterparty and expects a response of type T.
@@ -72,11 +72,7 @@ default Mono<Void> sendNotification(String method) {
 	 * Closes the session and releases any associated resources asynchronously.
 	 * @return a {@link Mono<Void>} that completes when the session has been closed.
 	 */
+	@Override
 	Mono<Void> closeGracefully();
 
-	/**
-	 * Closes the session and releases any associated resources.
-	 */
-	void close();
-
 }

Diff for: mcp/src/main/java/io/modelcontextprotocol/spec/McpTransport.java

@@ -35,25 +35,14 @@
  * @author Christian Tzolov
  * @author Dariusz Jędrzejczyk
  */
-public interface McpTransport {
-
-	/**
-	 * Closes the transport connection and releases any associated resources.
-	 *
-	 * <p>
-	 * This method ensures proper cleanup of resources when the transport is no longer
-	 * needed. It should handle the graceful shutdown of any active connections.
-	 * </p>
-	 */
-	default void close() {
-		this.closeGracefully().subscribe();
-	}
+public interface McpTransport extends AsyncCloseable {
 
 	/**
 	 * Closes the transport connection and releases any associated resources
 	 * asynchronously.
 	 * @return a {@link Mono<Void>} that completes when the connection has been closed.
 	 */
+	@Override
 	Mono<Void> closeGracefully();
 
 	/**

Diff for: mcp/src/test/java/io/modelcontextprotocol/server/transport/StdioServerTransportProviderTests.java

@@ -218,7 +218,7 @@ void shouldHandleSessionClose() throws Exception {
 		transportProvider.setSessionFactory(sessionFactory);
 
 		// Close the transport provider
-		transportProvider.close();
+		transportProvider.closeGracefully().block();
 
 		// Verify session was closed
 		verify(mockSession).closeGracefully();

Diff for: mcp/src/test/java/io/modelcontextprotocol/spec/McpClientSessionTests.java

@@ -53,7 +53,7 @@ void setUp() {
 	@AfterEach
 	void tearDown() {
 		if (session != null) {
-			session.close();
+			session.closeGracefully().block();
 		}
 	}