解决Go语言HTTP POST请求数据传输不匹配：PHP与Go实现差异解析

<?php
// ...
        $req['method'] = 'getinfo';
        $req['nonce'] = 1394503747386411;

        // 生成POST数据字符串
        $post_data = http_build_query($req, '', '&'); // 将关联数组转换为URL编码的字符串

        // ...
        curl_setopt($ch, CURLOPT_POSTFIELDS, $post_data); // 将URL编码的字符串作为POST请求体发送
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers); // 设置自定义HTTP头，包括Sign和Key
// ...
?>

// 原始Go语言代码片段（错误示例）
func PrivateCall(c appengine.Context) (map[string]interface{}, error) {
    AuthAPI := "https://api.cryptsy.com/api"
    // ...
    values := url.Values{}
    values.Set("method", "getinfo")
    values.Set("nonce", "1394503747386411")

    // 错误之处：将POST数据编码后附加到URL作为查询参数
    req, err := http.NewRequest("POST", AuthAPI+"?"+values.Encode(), nil)
    if err != nil {
        c.Infof("API - Call - error 2 - %s", err.Error())
        return nil, err
    }
    // ...
}

package main

import (
    "bytes"
    "context" // appengine.Context 现在是 context.Context
    "encoding/json"
    "io"
    "log"
    "net/http"
    "net/url"

    "google.golang.org/appengine"
    "google.golang.org/appengine/urlfetch"
)

// PrivateCallCorrectFormUrlencoded 演示如何在Go App Engine中发送 application/x-www-form-urlencoded 格式的POST请求
func PrivateCallCorrectFormUrlencoded(ctx context.Context) (map[string]interface{}, error) {
    AuthAPI := "https://api.cryptsy.com/api"
    APIKey := "90294318da0162b082c3d27126be80c3873955f9"
    signature := "75da1e3ff750286bf73d03197f1b779fbfff963fd7402941ae326509a6615eacb839b44f236b4d5ee6cff39321e7b35e9563a9a2075e99df0f4ee3b732999348"

    // 1. 构建POST表单数据
    formData := url.Values{}
    formData.Set("method", "getinfo")
    formData.Set("nonce", "1394503747386411")

    // 2. 将表单数据编码并转换为字节流作为请求体
    // http_build_query 的等效操作
    postBody := bytes.NewBufferString(formData.Encode())

    // 3. 创建POST请求。注意：URL中不再包含查询参数
    req, err := http.NewRequest("POST", AuthAPI, postBody)
    if err != nil {
        log.Printf("API - Call - error creating request: %s", err.Error())
        return nil, err
    }

    // 4. 设置请求头
    req.Header.Set("Content-Type", "application/x-www-form-urlencoded") // 关键：指定数据类型
    req.Header.Set("Key", APIKey)
    req.Header.Set("Sign", signature)
    // 模拟PHP的User-Agent，某些API可能依赖此进行识别
    req.Header.Set("User-Agent", "Mozilla/4.0 (compatible; Cryptsy API Go client; Go App Engine)")

    // 5. 使用urlfetch发送请求
    tr := urlfetch.Transport{Context: ctx}
    resp, err := tr.RoundTrip(req)
    if err != nil {
        log.Printf("API post error: %s", err)
        return nil, err
    }
    defer resp.Body.Close()

    // 6. 处理响应
    body, err := io.ReadAll(resp.Body) // io.ReadAll 替代 ioutil.ReadAll
    if err != nil {
        log.Printf("API read error: could not read body: %s", err)
        return nil, err
    }

    result := make(map[string]interface{})
    err = json.Unmarshal(body, &result)
    if err != nil {
        log.Printf("Unmarshal error: %v, body: %s", err, body)
        return nil, err
    }
    return result, nil
}

package main

import (
    "bytes"
    "context" // appengine.Context 现在是 context.Context
    "encoding/json"
    "io"
    "log"
    "net/http"

    "google.golang.org/appengine"
    "google.golang.org/appengine/urlfetch"
)

// PrivateCallCorrectJson 演示如何在Go App Engine中发送 application/json 格式的POST请求
func PrivateCallCorrectJson(ctx context.Context) (map[string]interface{}, error) {
    AuthAPI := "https://api.cryptsy.com/api"
    APIKey := "90294318da0162b082c3d27126be80c3873955f9"
    signature := "75da1e3ff750286bf73d03197f1b779fbfff963fd7402941ae326509a6615eacb839b44f236b4d5ee6cff39321e7b35e9563a9a2075e99df0f4ee3b732999348"

    // 1. 构建POST数据结构
    // 注意：结构体字段名必须大写才能被 json.Marshal 访问
    data := struct {
        Method string `json:"method"`
        Nonce  string `json:"nonce"`
    }{
        "getinfo",
        "1394503747386411",
    }

    // 2. 将数据编码为JSON
    postData, err := json.Marshal(data)
    if err != nil {
        log.