Golang通过http.NewRequest实现模拟请求

Golang通过http.NewRequest实现模拟请求，添加请求头和请求参数：

func DownloadString(remoteUrl string,queryValues url.Values) (body []byte,err error){
	client := &http.Client{};
	body = nil;
	uri,err := url.Parse(remoteUrl);
	if(err != nil){
		return ;
	}
	if(queryValues != nil){
		values := uri.Query();
		if(values != nil){
			for k,v := range values {
				queryValues[k] = v;
			}
		}
		uri.RawQuery = queryValues.Encode();
	}
	reqest,err := http.NewRequest("GET",uri.String(),nil);
	reqest.Header.Add("Accept","text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
	reqest.Header.Add("Accept-Encoding","gzip,deflate");
	reqest.Header.Add("Accept-Language","zh-cn,zh;q=0.8,en-us;q=0.5,en;q=0.3");
	reqest.Header.Add("Connection","keep-alive");
	reqest.Header.Add("Host",uri.Host);
	reqest.Header.Add("Referer",uri.String());
	reqest.Header.Add("User-Agent","Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20100101 Firefox/12.0");

	response,err := client.Do(reqest)
	defer response.Body.Close();
	if(err != nil){
		return ;
	}

	if response.StatusCode == 200 {
		switch response.Header.Get("content-encoding") {
		case "gzip":
			reader,_ := gzip.NewReader(response.Body)
			for {
				buf := make([]byte,1024)
				n,err := reader.Read(buf)

				if err != nil && err != io.EOF {
					panic(err)
				}

				if n == 0 {
					break
				}
				body = append(body,buf...);
			}
		default:
			body,_ = IoUtil.ReadAll(response.Body)

		}
	}
	return ;
}