在Go语言中，如何将HTTP请求返回的Unicode编码的中文字符转换为可读的中文字符？

package main

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

type ResponseData struct {
    // 定义一个结构体来匹配返回的JSON数据结构，根据实际情况调整字段
    PersonName string `json:"personname"`
    Age        int    `json:"age"`
    High       int    `json:"high"`
    Sex        string `json:"sex"`
    Class      struct {
        ClassName string `json:"classname"`
        Grade     int    `json:"grade"`
        Tt        struct {
            A string `json:"a"`
        } `json:"tt"`
    } `json:"class"`
    Message string `json:"message"`
}


func post(requrl string, headers map[string]string, reqproxy string) (string, error) {
    var client http.Client
    if reqproxy != "" {
        proxy, err := url.Parse(reqproxy)
        if err != nil {
            return "parse req_proxy fail", err
        }
        client.Transport = &http.Transport{
            Proxy: http.ProxyURL(proxy),
        }
    }
    data := []byte(`{"personname":"张三","age":18,"high":182,"sex":"男","class":{"classname":"1班","grade":3,"tt":{"a":"b"}},"message":"测试成功！"}`)
    req, err := http.NewRequest("POST", requrl, bytes.NewReader(data))
    if err != nil {
        return "", err
    }
    for key, value := range headers {
        req.Header.Set(key, value)
    }
    resp, err := client.Do(req)
    if err != nil {
        return "", err
    }
    defer resp.Body.Close() // 重要：关闭响应体
    body, err := io.ReadAll(resp.Body)
    if err != nil {
        return "", err
    }

    var responseData ResponseData
    err = json.Unmarshal(body, &responseData)
    if err != nil {
        return "", fmt.Errorf("JSON unmarshal error: %w", err)
    }

    return fmt.Sprintf("%+v", responseData), nil // 使用%+v打印结构体所有字段
}


func main() {
    headers := map[string]string{
        "User-Agent": "test",
        "Content-Type": "application/json", // 重要：设置Content-Type
    }
    content, err := post("http://httpbin.org/post", headers, "")
    if err != nil {
        fmt.Println("Error:", err)
    } else {
        fmt.Println(content)
    }
}