chore: Add AsyncCloseable interface.

Signed-off-by: He-Pin <hepin1989@gmail.com>

Author: He-Pin

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() {

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());
-			}
-		}
-
 	}
 
 }

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

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() {

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()

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());
-			}
-		}
-
 	}
 
 	/**

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();
 					}

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();
+}

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();
-	}
-
 }

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.
 	 */