理解Go语言rpc/jsonrpc与外部JSON-RPC服务的连接限制

package main

import (
    "fmt"
    "net/rpc/jsonrpc" // 注意：这是Go的rpc/jsonrpc包
)

func main() {
    // 错误示例：直接在地址中包含认证信息
    // Bitcoin Core的RPC接口通常是HTTP服务，且Go的jsonrpc.Dial不处理这种认证格式
    rc, e := jsonrpc.Dial("tcp", "user:pass@localhost:8332")
    if e != nil {
        fmt.Printf("Dial error: %v\n", e) // 会输出 "dial tcp user:pass@localhost:8332: too many colons in address"
        return
    }
    defer rc.Close()

    var blocks float64
    // 即使连接成功，此处的Call方法也可能因协议不兼容而失败
    err := rc.Call("getblockcount", "", &blocks)
    if err != nil {
        fmt.Printf("Call error: %v\n", err)
        return
    }
    fmt.Printf("Current block count: %f\n", blocks)
}

package main

import (
    "bytes"
    "encoding/json"
    "fmt"
    "io/ioutil"
    "net/http"
)

// JSONRPCRequest 定义了标准的JSON-RPC请求结构
type JSONRPCRequest struct {
    JSONRPC string        `json:"jsonrpc"`
    Method  string        `json:"method"`
    Params  []interface{} `json:"params"`
    ID      int           `json:"id"`
}

// JSONRPCResponse 定义了标准的JSON-RPC响应结构
type JSONRPCResponse struct {
    Result json.RawMessage `json:"result"`
    Error  json.RawMessage `json:"error"`
    ID     int             `json:"id"`
}

func main() {
    rpcUser := "your_rpc_username" // 替换为你的RPC用户名
    rpcPass := "your_rpc_password" // 替换为你的RPC密码
    rpcHost := "localhost"
    rpcPort := "8332" // Bitcoin Core RPC默认端口

    // 构造JSON-RPC请求体
    request := JSONRPCRequest{
        JSONRPC: "1.0", // Bitcoin Core通常使用JSON-RPC 1.0，但兼容2.0
        Method:  "getblockcount",
        Params:  []interface{}{}, // getblockcount方法通常不需要参数
        ID:      1,
    }

    requestBody, err := json.Marshal(request)
    if err != nil {
        fmt.Printf("Error marshalling request: %v\n", err)
        return
    }

    // 创建HTTP客户端
    client := &http.Client{}

    // 构建HTTP POST请求
    req, err := http.NewRequest("POST", fmt.Sprintf("http://%s:%s", rpcHost, rpcPort), bytes.NewBuffer(requestBody))
    if err != nil {
        fmt.Printf("Error creating request: %v\n", err)
        return
    }

    // 设置Content-Type头部
    req.Header.Set("Content-Type", "application/json")
    // 添加Basic Authentication头部
    req.SetBasicAuth(rpcUser, rpcPass)

    // 发送请求
    resp, err := client.Do(req)
    if err != nil {
        fmt.Printf("Error sending request: %v\n", err)
        return
    }
    defer resp.Body.Close()

    // 读取响应体
    responseBody, err := ioutil.ReadAll(resp.Body)
    if err != nil {
        fmt.Printf("Error reading response body: %v\n", err)
        return
    }

    if resp.StatusCode != http.StatusOK {
        fmt.Printf("RPC call failed with status code %d: %s\n", resp.StatusCode, string(responseBody))
        return
    }

    // 解析JSON-RPC响应
    var rpcResponse JSONRPCResponse
    err = json.Unmarshal(responseBody, &rpcResponse)
    if err != nil {
        fmt.Printf("Error unmarshalling response: %v\n", err)
        return
    }

    if rpcResponse.Error != nil && len(rpcResponse.Error) > 0 {
        fmt.Printf("RPC error: %s\n", string(rpcResponse.Error))
        return
    }

    var blockCount float64
    err = json.Unmarshal(rpcResponse.Result, &blockCount)
    if err != nil {
        fmt.Printf("Error unmarshalling result: %v\n", err)
        return
    }

    fmt.Printf("Current block count: %f\n", blockCount)
}