教学版 MCP client。 真实 MCP client 会通过 transport 发送 tools/list 和 tools/call; 这里用内存 handler 模拟外部 server,突出“发现工具”和“调用工具”两件事。
| 14 | * 这里用内存 handler 模拟外部 server,突出“发现工具”和“调用工具”两件事。 |
| 15 | */ |
| 16 | public class McpClient { |
| 17 | |
| 18 | public interface Handler { |
| 19 | |
| 20 | String handle(JSONObject input); |
| 21 | } |
| 22 | |
| 23 | private final String name; |
| 24 | |
| 25 | private List<McpToolDefinition> tools = Collections.emptyList(); |
| 26 | |
| 27 | private Map<String, Handler> handlers = new LinkedHashMap<>(); |
| 28 | |
| 29 | public McpClient(String name) { |
| 30 | this.name = name; |
| 31 | } |
| 32 | |
| 33 | public void register(List<McpToolDefinition> tools, Map<String, Handler> handlers) { |
| 34 | this.tools = tools == null ? Collections.emptyList() : tools; |
| 35 | this.handlers = handlers == null ? new LinkedHashMap<>() : handlers; |
| 36 | } |
| 37 | |
| 38 | public String callTool(String toolName, JSONObject input) { |
| 39 | Handler handler = handlers.get(toolName); |
| 40 | if (handler == null) { |
| 41 | return "MCP error: unknown tool '" + toolName + "'"; |
| 42 | } |
| 43 | try { |
| 44 | return handler.handle(input == null ? new JSONObject() : input); |
| 45 | } |
| 46 | catch (Exception e) { |
| 47 | return "MCP error: " + e.getMessage(); |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | public String getName() { |
| 52 | return name; |
| 53 | } |
| 54 | |
| 55 | public List<McpToolDefinition> getTools() { |
| 56 | return tools; |
| 57 | } |
| 58 | } |
nothing calls this directly
no outgoing calls
no test coverage detected