Spring AI MCP Server 的集成与实现。通过引入 Spring Boot Starter 依赖，结合 Model Context Protocol (MCP) Java SDK，实现了基于 SSE 的服务器端通信。示例展示了如何使用 RestClient 调用天气 API 并注册为工具，客户端如何通过 McpClient 连接服务器、列出并调用工具。文章还分析了 McpSchema 协议定义、McpSyncClient 同步封装以及 Spring Boot 自动配置类的工作原理，涵盖生命周期管理、工具调用、资源订阅等核心功能。
<dependencyManagement><dependencies><dependency><groupId>io.modelcontextprotocol.sdk</groupId><artifactId>mcp-bom</artifactId><version>0.8.0</version><type>pom</type><scope>import</scope></dependency></dependencies></dependencyManagement><dependency><groupId>io.modelcontextprotocol.sdk</groupId><artifactId>mcp</artifactId></dependency><!-- Spring WebFlux-based SSE client and server transport --><dependency><groupId>io.modelcontextprotocol.sdk</groupId><>mcp-spring-webflux io.modelcontextprotocol.sdk mcp-spring-webmvc
16:18:34.707 [HttpClient-1-Worker-0] INFO io.modelcontextprotocol.client.McpAsyncClient -- Server response with Protocol: 2024-11-05, Capabilities: ServerCapabilities[experimental=null, logging=LoggingCapabilities[], prompts=null, resources=null, tools=ToolCapabilities[listChanged=true]], Info: Implementation[name=my-weather-server, version=0.0.1] and Instructions null Available Tools = ListToolsResult[tools=[Tool[name=toUpperCase, description=Put the text to upper case, inputSchema=JsonSchema[type=object, properties={input={type=string}}, required=[input], additionalProperties=false]], Tool[name=getAlerts, description=Get weather alerts for a US state. Input is Two-letter US state code (e.g. CA, NY), inputSchema=JsonSchema[type=object, properties={state={type=string}}, required=[state], additionalProperties=false]], Tool[name=getWeatherForecastByLocation, description=Get weather forecast for a specific latitude/longitude, inputSchema=JsonSchema[type=object, properties={latitude={type=number, format=double}, longitude={type=number, format=double}}, required=[latitude, longitude], additionalProperties=false]]], nextCursor=null] Weather Forcast: CallToolResult[content=[TextContent[audience=null, priority=null, text="Overnight:\nTemperature: 50 F\nWind: 5 mph N\nForecast: Mostly cloudy, with a low around 50. North wind around 5 mph.\nWednesday:\nTemperature: 70 F\nWind: 2 to 7 mph NW\nForecast: A chance of rain showers between 9am and 5pm, then showers and thunderstorms. Some of the storms could be severe. Mostly cloudy. High near 70, with temperatures falling to around 68 in the afternoon. Northwest wind 2 to 7 mph. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.\nWednesday Night:\nTemperature: 48 F\nWind: 7 to 10 mph SSW\nForecast: Showers and thunderstorms before 5am, then rain. Some of the storms could be severe. Cloudy. Low around 48, with temperatures rising to around 50 overnight. South southwest wind 7 to 10 mph, with gusts as high as 21 mph. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.\nThursday:\nTemperature: 59 F\nWind: 9 mph S\nForecast: Rain. Cloudy, with a high near 59. South wind around 9 mph, with gusts as high as 21 mph. Chance of precipitation is 90%. New rainfall amounts between a tenth and quarter of an inch possible.\nThursday Night:\nTemperature: 47 F\nWind: 9 mph S\nForecast: Rain. Cloudy, with a low around 47. South wind around 9 mph, with gusts as high as 22 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.\nFriday:\nTemperature: 55 F\nWind: 9 to 13 mph S\nForecast: Rain. Cloudy, with a high near 55. Chance of precipitation is 100%. New rainfall amounts between a tenth and quarter of an inch possible.\nFriday Night:\nTemperature: 44 F\nWind: 6 to 10 mph S\nForecast: Rain. Mostly cloudy, with a low around 44. Chance of precipitation is 80%.\nSaturday:\nTemperature: 55 F\nWind: 7 mph S\nForecast: Rain likely. Partly sunny, with a high near 55.\nSaturday Night:\nTemperature: 41 F\nWind: 2 to 6 mph SE\nForecast: A chance of rain before 11pm. Mostly cloudy, with a low around 41.\nSunday:\nTemperature: 59 F\nWind: 2 to 6 mph NNE\nForecast: A chance of rain after 11am. Mostly cloudy, with a high near 59.\nSunday Night:\nTemperature: 45 F\nWind: 6 mph ESE\nForecast: Rain likely. Mostly cloudy, with a low around 45.\nMonday:\nTemperature: 54 F\nWind: 5 to 8 mph S\nForecast: Rain. Mostly cloudy, with a high near 54.\nMonday Night:\nTemperature: 42 F\nWind: 5 to 8 mph S\nForecast: Rain likely. Mostly cloudy, with a low around 42.\nTuesday:\nTemperature: 54 F\nWind: 7 mph SSW\nForecast: Rain likely. Mostly cloudy, with a high near 54.\n"]], isError=false] Alert Response = CallToolResult[content=[TextContent[audience=null, priority=null,]], isError=false]
源码
McpSchema
io/modelcontextprotocol/spec/McpSchema.java
publicfinalclassMcpSchema { privatestaticfinalLoggerlogger= LoggerFactory.getLogger(McpSchema.class); privateMcpSchema() { } publicstaticfinalStringLATEST_PROTOCOL_VERSION="2024-11-05"; publicstaticfinalStringJSONRPC_VERSION="2.0"; // --------------------------- // Method Names // --------------------------- // Lifecycle Methods public static final String METHOD_INITIALIZE = "initialize"; public static final String METHOD_NOTIFICATION_INITIALIZED = "notifications/initialized"; public static final String METHOD_PING = "ping"; // Tool Methods public static final String METHOD_TOOLS_LIST = "tools/list"; public static final String METHOD_TOOLS_CALL = "tools/call"; public static final String METHOD_NOTIFICATION_TOOLS_LIST_CHANGED = "notifications/tools/list_changed"; // Resources Methods public static final String METHOD_RESOURCES_LIST = "resources/list"; public static final String METHOD_RESOURCES_READ = "resources/read"; public static final String METHOD_NOTIFICATION_RESOURCES_LIST_CHANGED = "notifications/resources/list_changed"; public static final String METHOD_RESOURCES_TEMPLATES_LIST = "resources/templates/list"; public static final String METHOD_RESOURCES_SUBSCRIBE = "resources/subscribe"; public static final String METHOD_RESOURCES_UNSUBSCRIBE = "resources/unsubscribe"; // Prompt Methods public static final String METHOD_PROMPT_LIST = "prompts/list"; public static final String METHOD_PROMPT_GET = "prompts/get"; public static final String METHOD_NOTIFICATION_PROMPTS_LIST_CHANGED = "notifications/prompts/list_changed"; // Logging Methods public static final String METHOD_LOGGING_SET_LEVEL = "logging/setLevel"; public static final String METHOD_NOTIFICATION_MESSAGE = "notifications/message"; // Roots Methods public static final String METHOD_ROOTS_LIST = "roots/list"; public static final String METHOD_NOTIFICATION_ROOTS_LIST_CHANGED = "notifications/roots/list_changed"; // Sampling Methods public static final String METHOD_SAMPLING_CREATE_MESSAGE = "sampling/createMessage"; private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper(); //...... }
publicclassMcpSyncClientimplementsAutoCloseable { privatestaticfinalLoggerlogger= LoggerFactory.getLogger(McpSyncClient.class); // TODO: Consider providing a client config to set this properly // this is currently a concern only because AutoCloseable is used - perhaps it // is not a requirement? private static final long DEFAULT_CLOSE_TIMEOUT_MS = 1_000L; private final McpAsyncClient delegate; /** * Create a new McpSyncClient with the given delegate. * @param delegate the asynchronous kernel on top of which this synchronous client * provides a blocking API. * @deprecated This method will be removed in 0.9.0. Use * {@link McpClient#sync(McpClientTransport)} to obtain an instance. */ @Deprecated // TODO make the constructor package private post-deprecation public McpSyncClient(McpAsyncClient delegate) { Assert.notNull(delegate, "The delegate can not be null"); this.delegate = delegate; } /** * Get the server capabilities that define the supported features and functionality. * @return The server capabilities */ public McpSchema.ServerCapabilities getServerCapabilities() { return this.delegate.getServerCapabilities(); } /** * Get the server implementation information. * @return The server implementation details */ public McpSchema.Implementation getServerInfo() { return this.delegate.getServerInfo(); } /** * Get the client capabilities that define the supported features and functionality. * @return The client capabilities */ public ClientCapabilities getClientCapabilities() { return this.delegate.getClientCapabilities(); } /** * Get the client implementation information. * @return The client implementation details */ public McpSchema.Implementation getClientInfo() { return this.delegate.getClientInfo(); } @Override public void close() { this.delegate.close(); } public boolean closeGracefully() { try { this.delegate.closeGracefully().block(Duration.ofMillis(DEFAULT_CLOSE_TIMEOUT_MS)); } catch (RuntimeException e) { logger.warn("Client didn't close within timeout of {} ms.", DEFAULT_CLOSE_TIMEOUT_MS, e); return false; } return true; } /** * The initialization phase MUST be the first interaction between client and server. * During this phase: * <ul> * <li>Establish protocol version compatibility</li> * <li>Exchange and negotiate capabilities</li> * <li>Share implementation details</li> * </ul> * <br/> * The client MUST initiate this phase by sending an initialize request containing: * <ul> * <li>The protocol version the client supports</li> * <li>The client's capabilities</li> * <li>Client implementation information</li> * </ul> * * The server MUST respond with its own capabilities and information: * {@link McpSchema.ServerCapabilities}. <br/> * After successful initialization, the client MUST send an initialized notification * to indicate it is ready to begin normal operations. * * <br/> * * <a href= * "https://github.com/modelcontextprotocol/specification/blob/main/docs/specification/basic/lifecycle.md#initialization">Initialization * Spec</a> * @return the initialize result. */ public McpSchema.InitializeResult initialize() { // TODO: block takes no argument here as we assume the async client is // configured with a requestTimeout at all times return this.delegate.initialize().block(); } /** * Send a roots/list_changed notification. */ public void rootsListChangedNotification() { this.delegate.rootsListChangedNotification().block(); } /** * Add a roots dynamically. */ public void addRoot(McpSchema.Root root) { this.delegate.addRoot(root).block(); } /** * Remove a root dynamically. */ public void removeRoot(String rootUri) { this.delegate.removeRoot(rootUri).block(); } /** * Send a synchronous ping request. * @return */ public Object ping() { return this.delegate.ping().block(); } // -------------------------- // Tools // -------------------------- /** * Calls a tool provided by the server. Tools enable servers to expose executable * functionality that can interact with external systems, perform computations, and * take actions in the real world. * @param callToolRequest The request containing: - name: The name of the tool to call * (must match a tool name from tools/list) - arguments: Arguments that conform to the * tool's input schema * @return The tool execution result containing: - content: List of content items * (text, images, or embedded resources) representing the tool's output - isError: * Boolean indicating if the execution failed (true) or succeeded (false/absent) */ public McpSchema.CallToolResult callTool(McpSchema.CallToolRequest callToolRequest) { return this.delegate.callTool(callToolRequest).block(); } /** * Retrieves the list of all tools provided by the server. * @return The list of tools result containing: - tools: List of available tools, each * with a name, description, and input schema - nextCursor: Optional cursor for * pagination if more tools are available */ public McpSchema.ListToolsResult listTools() { return this.delegate.listTools().block(); } /** * Retrieves a paginated list of tools provided by the server. * @param cursor Optional pagination cursor from a previous list request * @return The list of tools result containing: - tools: List of available tools, each * with a name, description, and input schema - nextCursor: Optional cursor for * pagination if more tools are available */ public McpSchema.ListToolsResult listTools(String cursor) { return this.delegate.listTools(cursor).block(); } // -------------------------- // Resources // -------------------------- /** * Send a resources/list request. * @param cursor the cursor * @return the list of resources result. */ public McpSchema.ListResourcesResult listResources(String cursor) { return this.delegate.listResources(cursor).block(); } /** * Send a resources/list request. * @return the list of resources result. */ public McpSchema.ListResourcesResult listResources() { return this.delegate.listResources().block(); } /** * Send a resources/read request. * @param resource the resource to read * @return the resource content. */ public McpSchema.ReadResourceResult readResource(McpSchema.Resource resource) { return this.delegate.readResource(resource).block(); } /** * Send a resources/read request. * @param readResourceRequest the read resource request. * @return the resource content. */ public McpSchema.ReadResourceResult readResource(McpSchema.ReadResourceRequest readResourceRequest) { return this.delegate.readResource(readResourceRequest).block(); } /** * Resource templates allow servers to expose parameterized resources using URI * templates. Arguments may be auto-completed through the completion API. * * Request a list of resource templates the server has. * @param cursor the cursor * @return the list of resource templates result. */ public McpSchema.ListResourceTemplatesResult listResourceTemplates(String cursor) { return this.delegate.listResourceTemplates(cursor).block(); } /** * Request a list of resource templates the server has. * @return the list of resource templates result. */ public McpSchema.ListResourceTemplatesResult listResourceTemplates() { return this.delegate.listResourceTemplates().block(); } /** * Subscriptions. The protocol supports optional subscriptions to resource changes. * Clients can subscribe to specific resources and receive notifications when they * change. * * Send a resources/subscribe request. * @param subscribeRequest the subscribe request contains the uri of the resource to * subscribe to. */ public void subscribeResource(McpSchema.SubscribeRequest subscribeRequest) { this.delegate.subscribeResource(subscribeRequest).block(); } /** * Send a resources/unsubscribe request. * @param unsubscribeRequest the unsubscribe request contains the uri of the resource * to unsubscribe from. */ public void unsubscribeResource(McpSchema.UnsubscribeRequest unsubscribeRequest) { this.delegate.unsubscribeResource(unsubscribeRequest).block(); } // -------------------------- // Prompts // -------------------------- public ListPromptsResult listPrompts(String cursor) { return this.delegate.listPrompts(cursor).block(); } public ListPromptsResult listPrompts() { return this.delegate.listPrompts().block(); } public GetPromptResult getPrompt(GetPromptRequest getPromptRequest) { return this.delegate.getPrompt(getPromptRequest).block(); } /** * Client can set the minimum logging level it wants to receive from the server. * @param loggingLevel the min logging level */ public void setLoggingLevel(McpSchema.LoggingLevel loggingLevel) { this.delegate.setLoggingLevel(loggingLevel).block(); } }
