refactor(transport): Replace SseEmitter with queue-based SSE implementation in WebMvc transport

Replaces Spring's SseEmitter with a custom BlockingQueue-based SSE implementation in
WebMvcSseServerTransport for improved event delivery control and connection management.

The new implementation:
- Uses BlockingQueue for reliable event queuing and delivery
- Adds proper session management with dedicated SSEEvent record
- Improves error handling and timeout management
- Adds comprehensive integration tests

Resolves #57

samples/spring-ai-mcp-webmvc-sample/pom.xml

@@ -27,6 +27,13 @@
             <artifactId>mcp-webmvc-sse-transport</artifactId>
             <version>${spring-ai-mcp.version}</version>
         </dependency>
+        
+        <!-- Used only for the client webflux transport -->
+        <dependency>
+            <groupId>org.springframework.experimental</groupId>
+            <artifactId>mcp-webflux-sse-transport</artifactId>
+            <version>${spring-ai-mcp.version}</version>
+        </dependency>
         <dependency>
             <groupId>org.springframework.experimental</groupId>
             <artifactId>spring-ai-mcp</artifactId>

samples/spring-ai-mcp-webmvc-sample/src/main/java/org/springframework/ai/mcp/sample/webmvc/client/ClientWebFluxSse.java

@@ -0,0 +1,32 @@
+/*
+* Copyright 2024 - 2024 the original author or authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* https://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+package org.springframework.ai.mcp.sample.webmvc.client;
+
+import org.springframework.ai.mcp.client.transport.WebFluxSseClientTransport;
+import org.springframework.web.reactive.function.client.WebClient;
+
+/**
+ * @author Christian Tzolov
+ */
+public class ClientWebFluxSse {
+
+	public static void main(String[] args) {
+		var transport = new WebFluxSseClientTransport(WebClient.builder().baseUrl("http://localhost:8080"));
+
+		new SampleClient(transport).run();
+	}
+
+}

samples/spring-ai-mcp-webmvc-sample/src/main/java/org/springframework/ai/mcp/sample/webmvc/server/McpMvcServerApplication.java

@@ -0,0 +1,13 @@
+package org.springframework.ai.mcp.sample.webmvc.server;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class McpMvcServerApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(McpMvcServerApplication.class, args);
+	}
+
+}

samples/spring-ai-mcp-webmvc-sample/src/main/java/org/springframework/ai/mcp/sample/webmvc/server/McpServerConfig.java

@@ -31,8 +31,6 @@ import org.springframework.context.annotation.Configuration;
 import org.springframework.web.client.RestClient;
 import org.springframework.web.servlet.config.annotation.EnableWebMvc;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
-import org.springframework.http.converter.HttpMessageConverter;
-import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
 import org.springframework.web.servlet.function.RouterFunction;
 import org.springframework.web.servlet.function.ServerResponse;
 
@@ -40,14 +38,6 @@ import org.springframework.web.servlet.function.ServerResponse;
 @EnableWebMvc
 public class McpServerConfig implements WebMvcConfigurer {
 
-	@Override
-	public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
-		MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
-		converter.setSupportedMediaTypes(List.of(org.springframework.http.MediaType.APPLICATION_JSON,
-				org.springframework.http.MediaType.TEXT_EVENT_STREAM));
-		converters.add(converter);
-	}
-
 	private static final Logger logger = LoggerFactory.getLogger(McpServerConfig.class);
 
 	@Bean

samples/spring-ai-mcp-webmvc-sample/src/main/resources/application.properties

@@ -1,8 +1,8 @@
-# spring.main.web-application-type=none
+spring.main.web-application-type=SERVLET
 
 # NOTE: You must disable the banner and the console logging 
 # to allow the STDIO transport to work !!!
 spring.main.banner-mode=off
-# logging.pattern.console=
+logging.pattern.console=
 
 transport.mode=sse