Spring AI MCP Server 集成与源码解析

Spring AI MCP扩展依赖

<dependency>
  <groupId>org.springframework.ai</groupId>
  <artifactId>spring-ai-starter-mcp-server-webmvc</artifactId>
</dependency>

工具注册示例

配置类

@Bean
public ToolCallbackProvider weatherTools(WeatherService weatherService) {
  return MethodToolCallbackProvider.builder()
    .toolObjects(weatherService)
    .build();
}

@Bean
public ToolCallback toUpperCase() {
  return FunctionToolCallback.builder("toUpperCase", input -> input.input().toUpperCase())
    .inputType(TextInput.class)
    .description("Convert text to uppercase")
    .build();
}

WeatherService实现

@Service
public class WeatherService {
  private static final String BASE_URL = "https://api.weather.gov";
  private final RestClient restClient;

  public WeatherService() {
    this.restClient = RestClient.builder()
      .baseUrl(BASE_URL)
      .defaultHeader("Accept", "application/geo+json")
      .defaultHeader("User-Agent", "WeatherApiClient/1.0")
      .build();
  }

  @Tool(description = "Get weather forecast by location")
  public String getWeatherForecastByLocation(double latitude, double longitude) {
    var points = restClient.get()
      .uri("/points/{lat},{lon}", latitude, longitude)
      .retrieve()
      .body(Points.class);
    // 处理预报数据...
  }

  @Tool(description = "Get weather alerts for state")
  public String getAlerts(String state) {
    Alert alert = restClient.get()
      .uri("/alerts/active/area/{state}", state)
      .retrieve()
      .body(Alert.class);
    // 处理警报数据...
  }
}

客户端调用示例

var transport = new HttpClientSseClientTransport("http://localhost:8080");
var client = McpClient.sync(transport).build();
client.initialize();

// 获取可用工具列表
ListToolsResult tools = client.listTools();

// 调用天气查询工具
CallToolResult result = client.callTool(
  new CallToolRequest("getWeatherForecastByLocation",
    Map.of("latitude", "47.6062", "longitude", "-122.3321"))
);

核心源码解析

McpSchema协议定义

定义了生命周期方法（initialize/ping）、工具操作（tools/list/call）等标准接口。

McpSyncClient同步封装

提供阻塞式API，内部委托McpAsyncClient实现异步操作。

自动配置类

• McpServerAutoConfiguration: 注册同步/异步服务器实例
• McpWebMvcServerAutoConfiguration: 配置WebMVC SSE传输层

总结

Spring AI MCP Server通过标准化协议实现AI模型与外部工具的桥接，支持工具注册、资源管理和提示词交互。核心架构采用分层设计，底层协议由Model Context Protocol规范定义，上层通过Spring Boot自动配置简化集成流程。