如何用 Golang 编写一个天气查询程序_Golang API 调用与 JSON 解析实战

type Weather struct {
    Main struct {
        Temp     float64 `json:"temp"`
        Humidity int     `json:"humidity"`
    } `json:"main"`
    Name string `json:"name"`
    Sys  struct {
        Country string `json:"country"`
    } `json:"sys"`
}

func getWeather(city, apiKey string) (*Weather, error) {
    url := fmt.Sprintf("https://api.openweathermap.org/data/2.5/weather?q=%s&appid=%s&units=metric", city, apiKey)
    
    resp, err := http.Get(url)
    if err != nil {
        return nil, err
    }
    defer resp.Body.Close()

    if resp.StatusCode != 200 {
        return nil, fmt.Errorf("天气服务错误: %s", resp.Status)
    }

    var weather Weather
    err = json.NewDecoder(resp.Body).Decode(&weather)
    if err != nil {
        return nil, err
    }

    return &weather, nil
}

func main() {
    apiKey := "your_api_key_here"
    city := "Beijing"

    weather, err := getWeather(city, apiKey)
    if err != nil {
        log.Fatal(err)
    }

    fmt.Printf("城市: %s, 国家: %s\n", weather.Name, weather.Sys.Country)
    fmt.Printf("温度: %.1f°C\n", weather.Main.Temp)
    fmt.Printf("湿度: %d%%\n", weather.Main.Humidity)
}