refactor(module11): restructure MCP client implementation and migrate to chapter 11

m11_mcp_advanced/transports/http.py

@@ -0,0 +1,130 @@
+import json
+import uuid
+from typing import Optional,Literal
+
+import httpx
+
+
+class HttpMCPTransport:
+    def __init__(self,url:str=None):
+        """
+        MCP 客户端 - 支持 stdio 与 HTTP 两种传输方式
+
+        :param url: http模式的端点 URL
+        """
+        if not url:
+            raise ValueError("HTTP模式必须提供url参数")
+        self.url = url
+        self.session_id:Optional[str] = None
+        self.http_client:Optional[httpx.AsyncClient] = None
+
+
+
+    async def connect(self):
+        """建立MCP长连接（一次连接，多次调用）"""
+        if self.http_client:
+            return
+        self.http_client = httpx.AsyncClient(timeout=60.0)
+
+        # 发送 initialize 请求
+        response = await self._http_request("initialize",{
+            "protocolVersion":"2024-11-05",
+            "capabilities":{},
+            "clientInfo":{"name":"mcp-client","version":"1.0"}
+        })
+
+        # 保存session ID
+        if response and "result" in response:
+            # Session ID在响应头内
+            pass # 已在_http_request中处理
+
+
+    async def list_tools(self):
+        """查询工具列表，为LLM建立上下文用"""
+        if not self.http_client:
+            raise RuntimeError("未连接，请先 connect()")
+
+        result = await self._http_request("tools/list")
+        if result and "result" in result:
+            tools = result["result"].get("tools",[])
+            return [
+                {
+                    "name":tool["name"],
+                    "description":tool["description"],
+                    "input_schema":tool.get("inputSchema",{})
+                }
+                for tool in tools
+            ]
+        return []
+
+
+    async def call_tool(self,name:str,args:dict):
+        """调用工具（工程化：加上防御性处理）"""
+        if not self.http_client:
+            raise RuntimeError("未连接，请先 connect()")
+
+        result = await self._http_request("tools/call",{
+            "name":name,
+            "arguments":args
+        })
+        if result and "result" in result:
+            content = result["result"].get("content",{})
+            if content and len(content):
+                return content[0].get("text",str(content[0]))
+
+        return "工具执行成功，但无文本返回"
+
+
+    async def cleanup(self):
+        """关闭MCP服务、会话和transport"""
+        if self.http_client:
+            await self.http_client.aclose()
+            self.http_client = None
+            self.session_id = None
+
+
+    async def _http_request(self, method: str, params: dict = None):
+        """ 发送 HTTP JSON-RPC 请求 """
+        payload = {
+            "jsonrpc": "2.0",
+            "id": str(uuid.uuid4()),
+            "method": method,
+        }
+        if params:
+            payload["params"] = params
+
+        headers = {
+            "Content-Type": "application/json",
+            "Accept": "application/json, text/event-stream"
+        }
+        if self.session_id:
+            headers["Mcp-Session-Id"] = self.session_id
+
+        response = await self.http_client.post(
+            self.url,
+            json=payload,
+            headers=headers
+        )
+
+        if "Mcp-Session-Id" in response.headers:
+            self.session_id = response.headers["Mcp-Session-Id"]
+
+        response.raise_for_status()
+
+        # 判断响应类型
+        content_type = response.headers.get("Content-Type", "")
+
+        if "text/event-stream" in content_type:
+            # SSE 流式响应（本地服务器）
+            for line in response.text.split('\n'):
+                line = line.strip()
+                if line.startswith("data:"):
+                    data_str = line[5:].strip()
+                    try:
+                        return json.loads(data_str)
+                    except json.JSONDecodeError:
+                        pass
+            return None
+        else:
+            # 普通 JSON 响应（云端服务）
+            return response.json()