spring-ai-starter-mcp-client小试牛刀

序

本文主要研究下如何使用spring-ai-starter-mcp-client

步骤

pom.xml

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

        <dependency>
            <groupId>org.springframework.ai</groupId>
            <artifactId>spring-ai-ollama-spring-boot-starter</artifactId>
        </dependency>

application.yml

spring:
  application:
    name: mcp-client-example
  main:
    web-application-type: none
  ai:
    ollama:
      base-url: http://localhost:11434
      chat:
        model: qwen2.5:latest
    mcp:
      client:
        enabled: true
        name: my-mcp-client
        version: 1.0.0
        request-timeout: 30s
        type: SYNC  # or ASYNC for reactive applications
        sse:
          connections:
            server1:
              url: http://localhost:8080
#            server2:
#              url: http://otherserver:8081
        toolcallback:
          enabled: 'true'
logging:
  level:
    io:
      modelcontextprotocol:
        client: WARN
        spec: WARN

示例

    @Bean
    public CommandLineRunner predefinedQuestions(ChatClient.Builder chatClientBuilder,
            ConfigurableApplicationContext context, SyncMcpToolCallbackProvider toolCallbackProvider) {

        return args -> {

            var chatClient = chatClientBuilder
                    .defaultTools(toolCallbackProvider)
                    .defaultAdvisors(new MessageChatMemoryAdvisor(new InMemoryChatMemory()))
                    .build();

            System.out.println("\n>>> ASSISTANT: " + chatClient.prompt("帮我调用tool查一下xxx").call().content());
            System.out.println("\n>>> ASSISTANT: " + chatClient.prompt("取出create_time的最大值").call().content());

            context.close();
        };
    }

源码

McpClientAutoConfiguration

org/springframework/ai/mcp/client/autoconfigure/McpClientAutoConfiguration.java

@AutoConfiguration(after = { StdioTransportAutoConfiguration.class, SseHttpClientTransportAutoConfiguration.class,
        SseWebFluxTransportAutoConfiguration.class })
@ConditionalOnClass({ McpSchema.class })
@EnableConfigurationProperties(McpClientCommonProperties.class)
@ConditionalOnProperty(prefix = McpClientCommonProperties.CONFIG_PREFIX, name = "enabled", havingValue = "true",
        matchIfMissing = true)
public class McpClientAutoConfiguration {

    /**
     * Create a dynamic client name based on the client name and the name of the server
     * connection.
     * @param clientName the client name as defined by the configuration
     * @param serverConnectionName the name of the server connection being used by the
     * client
     * @return the connected client name
     */
    private String connectedClientName(String clientName, String serverConnectionName) {
        return clientName + " - " + serverConnectionName;
    }

    /**
     * Creates a list of {@link McpSyncClient} instances based on the available
     * transports.
     *
     * <p>
     * Each client is configured with:
     * <ul>
     * <li>Client information (name and version) from common properties
     * <li>Request timeout settings
     * <li>Custom configurations through {@link McpSyncClientConfigurer}
     * </ul>
     *
     * <p>
     * If initialization is enabled in properties, the clients are automatically
     * initialized.
     * @param mcpSyncClientConfigurer the configurer for customizing client creation
     * @param commonProperties common MCP client properties
     * @param transportsProvider provider of named MCP transports
     * @return list of configured MCP sync clients
     */
    @Bean
    @ConditionalOnProperty(prefix = McpClientCommonProperties.CONFIG_PREFIX, name = "type", havingValue = "SYNC",
            matchIfMissing = true)
    public List<McpSyncClient> mcpSyncClients(McpSyncClientConfigurer mcpSyncClientConfigurer,
            McpClientCommonProperties commonProperties,
            ObjectProvider<List<NamedClientMcpTransport>> transportsProvider) {

        List<McpSyncClient> mcpSyncClients = new ArrayList<>();

        List<NamedClientMcpTransport> namedTransports = transportsProvider.stream().flatMap(List::stream).toList();

        if (!CollectionUtils.isEmpty(namedTransports)) {
            for (NamedClientMcpTransport namedTransport : namedTransports) {

                McpSchema.Implementation clientInfo = new McpSchema.Implementation(
                        this.connectedClientName(commonProperties.getName(), namedTransport.name()),
                        commonProperties.getVersion());

                McpClient.SyncSpec syncSpec = McpClient.sync(namedTransport.transport())
                    .clientInfo(clientInfo)
                    .requestTimeout(commonProperties.getRequestTimeout());

                syncSpec = mcpSyncClientConfigurer.configure(namedTransport.name(), syncSpec);

                var syncClient = syncSpec.build();

                if (commonProperties.isInitialized()) {
                    syncClient.initialize();
                }

                mcpSyncClients.add(syncClient);
            }
        }

        return mcpSyncClients;
    }

    //......
}    

McpClientAutoConfiguration依赖McpClientCommonProperties，它根据McpClientCommonProperties和List<NamedClientMcpTransport>构建List<McpSyncClient>及List<McpAsyncClient>

McpToolCallbackAutoConfiguration

org/springframework/ai/mcp/client/autoconfigure/McpToolCallbackAutoConfiguration.java

@AutoConfiguration(after = { McpClientAutoConfiguration.class })
@EnableConfigurationProperties(McpClientCommonProperties.class)
@Conditional(McpToolCallbackAutoConfiguration.McpToolCallbackAutoconfigurationCondition.class)
public class McpToolCallbackAutoConfiguration {

    public static class McpToolCallbackAutoconfigurationCondition extends AllNestedConditions {

        public McpToolCallbackAutoconfigurationCondition() {
            super(ConfigurationPhase.PARSE_CONFIGURATION);
        }

        @ConditionalOnProperty(prefix = McpClientCommonProperties.CONFIG_PREFIX, name = "enabled", havingValue = "true",
                matchIfMissing = true)
        static class McpAutoConfigEnabled {

        }

        @ConditionalOnProperty(prefix = McpClientCommonProperties.CONFIG_PREFIX + ".toolcallback", name = "enabled",
                havingValue = "true", matchIfMissing = false)
        static class ToolCallbackProviderEnabled {

        }

    }

    /**
     * Creates tool callbacks for all configured MCP clients.
     *
     * <p>
     * These callbacks enable integration with Spring AI's tool execution framework,
     * allowing MCP tools to be used as part of AI interactions.
     * @param syncMcpClients provider of MCP sync clients
     * @return list of tool callbacks for MCP integration
     */
    @Bean
    @ConditionalOnProperty(prefix = McpClientCommonProperties.CONFIG_PREFIX, name = "type", havingValue = "SYNC",
            matchIfMissing = true)
    public ToolCallbackProvider mcpToolCallbacks(ObjectProvider<List<McpSyncClient>> syncMcpClients) {
        List<McpSyncClient> mcpClients = syncMcpClients.stream().flatMap(List::stream).toList();
        return new SyncMcpToolCallbackProvider(mcpClients);
    }

    @Bean
    @ConditionalOnProperty(prefix = McpClientCommonProperties.CONFIG_PREFIX, name = "type", havingValue = "ASYNC")
    public ToolCallbackProvider mcpAsyncToolCallbacks(ObjectProvider<List<McpAsyncClient>> mcpClientsProvider) {
        List<McpAsyncClient> mcpClients = mcpClientsProvider.stream().flatMap(List::stream).toList();
        return new AsyncMcpToolCallbackProvider(mcpClients);
    }

}

McpToolCallbackAutoConfiguration在spring.ai.mcp.client.enabled及spring.ai.mcp.client.toolcallback.enabled都为true时才生效，它会根据List<McpSyncClient>去创建SyncMcpToolCallbackProvider或AsyncMcpToolCallbackProvider

小结

spring ai提供了spring-ai-starter-mcp-client用于快速集成mcpClient到chatClient中；McpClientAutoConfiguration依赖McpClientCommonProperties，它根据McpClientCommonProperties和List<NamedClientMcpTransport>构建List<McpSyncClient>及List<McpAsyncClient>；McpToolCallbackAutoConfiguration在spring.ai.mcp.client.enabled及spring.ai.mcp.client.toolcallback.enabled都为true时才生效，它会根据List<McpSyncClient>去创建SyncMcpToolCallbackProvider或AsyncMcpToolCallbackProvider

doc

• MCP Client Boot Starter