Golang NewDecoder 예제들

예제 #1

파일: client.go 프로젝트: yangxiaoyi-git/wechat

// GET 微信资源, 然后将微信服务器返回的 JSON 用 encoding/json 解析到 response.
//
//  NOTE:
//  1. 一般不用调用这个方法, 请直接调用高层次的封装方法;
//  2. 最终的 URL == incompleteURL + access_token;
//  3. response 格式有要求, 要么是 *Error, 要么是下面结构体的指针(注意 Error 必须是第一个 Field):
//      struct {
//          Error
//          ...
//      }
func (clt *Client) GetJSON(incompleteURL string, response interface{}) (err error) {
	token, err := clt.Token()
	if err != nil {
		return
	}

	hasRetried := false
RETRY:
	finalURL := incompleteURL + url.QueryEscape(token)

	httpResp, err := clt.HttpClient.Get(finalURL)
	if err != nil {
		return
	}
	defer httpResp.Body.Close()

	if httpResp.StatusCode != http.StatusOK {
		return fmt.Errorf("http.Status: %s", httpResp.Status)
	}

	if err = json.NewDecoder(httpResp.Body).Decode(response); err != nil {
		return
	}

	var ErrorStructValue reflect.Value // Error

	// 下面的代码对 response 有特定要求, 见此函数 NOTE
	responseStructValue := reflect.ValueOf(response).Elem()
	if v := responseStructValue.Field(0); v.Kind() == reflect.Struct {
		ErrorStructValue = v
	} else {
		ErrorStructValue = responseStructValue
	}

	switch ErrCode := ErrorStructValue.Field(0).Int(); ErrCode {
	case ErrCodeOK:
		return
	case ErrCodeAccessTokenExpired:
		ErrMsg := ErrorStructValue.Field(1).String()
		LogInfoln("[WECHAT_RETRY] err_code:", ErrCode, ", err_msg:", ErrMsg)
		LogInfoln("[WECHAT_RETRY] current token:", token)

		if !hasRetried {
			hasRetried = true

			if token, err = clt.TokenRefresh(); err != nil {
				return
			}
			LogInfoln("[WECHAT_RETRY] new token:", token)

			responseStructValue.Set(reflect.New(responseStructValue.Type()).Elem())
			goto RETRY
		}
		LogInfoln("[WECHAT_RETRY] fallthrough, current token:", token)
		fallthrough
	default:
		return
	}
}

예제 #2

파일: client_media.go 프로젝트: yangxiaoyi-git/wechat

// 下载多媒体到 io.Writer.
func (clt *Client) downloadMediaToWriter(mediaId string, writer io.Writer) (written int64, err error) {
	token, err := clt.Token()
	if err != nil {
		return
	}

	hasRetried := false
RETRY:
	finalURL := "https://api.weixin.qq.com/cgi-bin/media/get?media_id=" + url.QueryEscape(mediaId) +
		"&access_token=" + url.QueryEscape(token)

	httpResp, err := clt.HttpClient.Get(finalURL)
	if err != nil {
		return
	}
	defer httpResp.Body.Close()

	if httpResp.StatusCode != http.StatusOK {
		err = fmt.Errorf("http.Status: %s", httpResp.Status)
		return
	}

	ContentType, _, _ := mime.ParseMediaType(httpResp.Header.Get("Content-Type"))
	if ContentType != "text/plain" && ContentType != "application/json" { // 返回的是媒体流
		return io.Copy(writer, httpResp.Body)
	}

	// 返回的是错误信息
	var result mp.Error
	if err = json.NewDecoder(httpResp.Body).Decode(&result); err != nil {
		return
	}

	switch result.ErrCode {
	case mp.ErrCodeOK:
		return // 基本不会出现
	case mp.ErrCodeInvalidCredential, mp.ErrCodeAccessTokenExpired: // 失效(过期)重试一次
		mp.LogInfoln("[WECHAT_RETRY] err_code:", result.ErrCode, ", err_msg:", result.ErrMsg)
		mp.LogInfoln("[WECHAT_RETRY] current token:", token)

		if !hasRetried {
			hasRetried = true

			if token, err = clt.TokenRefresh(); err != nil {
				return
			}
			mp.LogInfoln("[WECHAT_RETRY] new token:", token)

			result = mp.Error{}
			goto RETRY
		}
		mp.LogInfoln("[WECHAT_RETRY] fallthrough, current token:", token)
		fallthrough
	default:
		err = &result
		return
	}
}

예제 #3

파일: client.go 프로젝트: yangxiaoyi-git/wechat

func (clt *Client) getJSON(url string, response interface{}) (err error) {
	httpResp, err := clt.httpClient().Get(url)
	if err != nil {
		return
	}
	defer httpResp.Body.Close()

	if httpResp.StatusCode != http.StatusOK {
		return fmt.Errorf("http.Status: %s", httpResp.Status)
	}

	return json.NewDecoder(httpResp.Body).Decode(response)
}

예제 #4

파일: access_token_server.go 프로젝트: yangxiaoyi-git/wechat

// 从微信服务器获取 access_token.
//  同一时刻只能一个 goroutine 进入, 防止没必要的重复获取.
func (srv *DefaultAccessTokenServer) getToken() (token accessTokenInfo, cached bool, err error) {
	srv.tokenGet.Lock()
	defer srv.tokenGet.Unlock()

	timeNowUnix := time.Now().Unix()

	// 在收敛周期内直接返回最近一次获取的 access_token,
	// 这里的收敛时间设定为2秒, 因为在同一个进程内, 收敛周期为2个http周期
	if n := srv.tokenGet.LastTimestamp; n <= timeNowUnix && timeNowUnix < n+2 {
		// 因为只有成功获取后才会更新 srv.tokenGet.LastTimestamp, 所以这些都是有效数据
		token = accessTokenInfo{
			Token:     srv.tokenGet.LastTokenInfo.Token,
			ExpiresIn: srv.tokenGet.LastTokenInfo.ExpiresIn - timeNowUnix + n,
		}
		cached = true
		return
	}

	_url := "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=" + url.QueryEscape(srv.appId) +
		"&secret=" + url.QueryEscape(srv.appSecret)
	httpResp, err := srv.httpClient.Get(_url)
	if err != nil {
		srv.tokenCache.Lock()
		srv.tokenCache.Token = ""
		srv.tokenCache.Unlock()
		return
	}
	defer httpResp.Body.Close()

	if httpResp.StatusCode != http.StatusOK {
		srv.tokenCache.Lock()
		srv.tokenCache.Token = ""
		srv.tokenCache.Unlock()

		err = fmt.Errorf("http.Status: %s", httpResp.Status)
		return
	}

	var result struct {
		Error
		accessTokenInfo
	}

	if err = json.NewDecoder(httpResp.Body).Decode(&result); err != nil {
		srv.tokenCache.Lock()
		srv.tokenCache.Token = ""
		srv.tokenCache.Unlock()
		return
	}

	if result.ErrCode != ErrCodeOK {
		srv.tokenCache.Lock()
		srv.tokenCache.Token = ""
		srv.tokenCache.Unlock()

		err = &result.Error
		return
	}

	// 由于网络的延时, access_token 过期时间留了一个缓冲区
	switch {
	case result.ExpiresIn > 31556952: // 60*60*24*365.2425
		srv.tokenCache.Lock()
		srv.tokenCache.Token = ""
		srv.tokenCache.Unlock()

		err = errors.New("expires_in too large: " + strconv.FormatInt(result.ExpiresIn, 10))
		return
	case result.ExpiresIn > 60*60:
		result.ExpiresIn -= 60 * 10
	case result.ExpiresIn > 60*30:
		result.ExpiresIn -= 60 * 5
	case result.ExpiresIn > 60*5:
		result.ExpiresIn -= 60
	case result.ExpiresIn > 60:
		result.ExpiresIn -= 10
	default:
		srv.tokenCache.Lock()
		srv.tokenCache.Token = ""
		srv.tokenCache.Unlock()

		err = errors.New("expires_in too small: " + strconv.FormatInt(result.ExpiresIn, 10))
		return
	}

	// 更新 tokenGet 信息
	srv.tokenGet.LastTokenInfo = result.accessTokenInfo
	srv.tokenGet.LastTimestamp = timeNowUnix

	// 更新缓存
	srv.tokenCache.Lock()
	srv.tokenCache.Token = result.accessTokenInfo.Token
	srv.tokenCache.Unlock()

	token = result.accessTokenInfo
	return
}

예제 #5

파일: client.go 프로젝트: yangxiaoyi-git/wechat

// 用 encoding/json 把 request marshal 为 JSON, 放入 http 请求的 body 中,
// POST 到微信服务器, 然后将微信服务器返回的 JSON 用 encoding/json 解析到 response.
//
//  NOTE:
//  1. 一般不用调用这个方法, 请直接调用高层次的封装方法;
//  2. 最终的 URL == incompleteURL + access_token;
//  3. response 格式有要求, 要么是 *Error, 要么是下面结构体的指针(注意 Error 必须是第一个 Field):
//      struct {
//          Error
//          ...
//      }
func (clt *Client) PostJSON(incompleteURL string, request interface{}, response interface{}) (err error) {
	buf := textBufferPool.Get().(*bytes.Buffer)
	buf.Reset()
	defer textBufferPool.Put(buf)

	if err = json.NewEncoder(buf).Encode(request); err != nil {
		return
	}
	requestBytes := buf.Bytes()

	token, err := clt.Token()
	if err != nil {
		return
	}

	hasRetried := false
RETRY:
	finalURL := incompleteURL + url.QueryEscape(token)

	httpResp, err := clt.HttpClient.Post(finalURL, "application/json; charset=utf-8", bytes.NewReader(requestBytes))
	if err != nil {
		return
	}
	defer httpResp.Body.Close()

	if httpResp.StatusCode != http.StatusOK {
		return fmt.Errorf("http.Status: %s", httpResp.Status)
	}

	if err = json.NewDecoder(httpResp.Body).Decode(response); err != nil {
		return
	}

	var ErrorStructValue reflect.Value // Error

	// 下面的代码对 response 有特定要求, 见此函数 NOTE
	responseStructValue := reflect.ValueOf(response).Elem()
	if v := responseStructValue.Field(0); v.Kind() == reflect.Struct {
		ErrorStructValue = v
	} else {
		ErrorStructValue = responseStructValue
	}

	switch ErrCode := ErrorStructValue.Field(0).Int(); ErrCode {
	case ErrCodeOK:
		return
	case ErrCodeInvalidCredential, ErrCodeAccessTokenExpired:
		ErrMsg := ErrorStructValue.Field(1).String()
		LogInfoln("[WECHAT_RETRY] err_code:", ErrCode, ", err_msg:", ErrMsg)
		LogInfoln("[WECHAT_RETRY] current token:", token)

		if !hasRetried {
			hasRetried = true

			if token, err = clt.TokenRefresh(); err != nil {
				return
			}
			LogInfoln("[WECHAT_RETRY] new token:", token)

			responseStructValue.Set(reflect.New(responseStructValue.Type()).Elem())
			goto RETRY
		}
		LogInfoln("[WECHAT_RETRY] fallthrough, current token:", token)
		fallthrough
	default:
		return
	}
}

예제 #6

파일: access_token_server.go 프로젝트: yangxiaoyi-git/wechat

// 从微信服务器获取 component_access_token.
//  同一时刻只能一个 goroutine 进入, 防止没必要的重复获取.
func (srv *DefaultAccessTokenServer) getToken() (token accessTokenInfo, cached bool, err error) {
	srv.tokenGet.Lock()
	defer srv.tokenGet.Unlock()

	timeNowUnix := time.Now().Unix()

	// 在收敛周期内直接返回最近一次获取的 component_access_token, 这里的收敛时间设定为4秒.
	if n := srv.tokenGet.LastTimestamp; n <= timeNowUnix && timeNowUnix < n+4 {
		// 因为只有成功获取后才会更新 srv.tokenGet.LastTimestamp, 所以这些都是有效数据
		token = accessTokenInfo{
			Token:     srv.tokenGet.LastTokenInfo.Token,
			ExpiresIn: srv.tokenGet.LastTokenInfo.ExpiresIn - timeNowUnix + n,
		}
		cached = true
		return
	}

	verifyTicket, err := srv.verifyTicketGetter.GetComponentVerifyTicket(srv.appId)
	if err != nil {
		srv.tokenCache.Lock()
		srv.tokenCache.Token = ""
		srv.tokenCache.Unlock()
		return
	}

	request := struct {
		AppId        string `json:"component_appid"`
		AppSecret    string `json:"component_appsecret"`
		VerifyTicket string `json:"component_verify_ticket"`
	}{
		AppId:        srv.appId,
		AppSecret:    srv.appSecret,
		VerifyTicket: verifyTicket,
	}

	requestBuf := textBufferPool.Get().(*bytes.Buffer)
	requestBuf.Reset()
	defer textBufferPool.Put(requestBuf)

	if err = json.NewEncoder(requestBuf).Encode(&request); err != nil {
		srv.tokenCache.Lock()
		srv.tokenCache.Token = ""
		srv.tokenCache.Unlock()
		return
	}

	url := "https://api.weixin.qq.com/cgi-bin/component/api_component_token"
	httpResp, err := srv.httpClient.Post(url, "application/json; charset=utf-8", requestBuf)
	if err != nil {
		srv.tokenCache.Lock()
		srv.tokenCache.Token = ""
		srv.tokenCache.Unlock()
		return
	}
	defer httpResp.Body.Close()

	if httpResp.StatusCode != http.StatusOK {
		srv.tokenCache.Lock()
		srv.tokenCache.Token = ""
		srv.tokenCache.Unlock()

		err = fmt.Errorf("http.Status: %s", httpResp.Status)
		return
	}

	var result struct {
		mp.Error
		accessTokenInfo
	}

	if err = json.NewDecoder(httpResp.Body).Decode(&result); err != nil {
		srv.tokenCache.Lock()
		srv.tokenCache.Token = ""
		srv.tokenCache.Unlock()
		return
	}

	if result.ErrCode != mp.ErrCodeOK {
		srv.tokenCache.Lock()
		srv.tokenCache.Token = ""
		srv.tokenCache.Unlock()

		err = &result.Error
		return
	}

	// 由于网络的延时, component_access_token 过期时间留了一个缓冲区
	switch {
	case result.ExpiresIn > 31556952: // 60*60*24*365.2425
		srv.tokenCache.Lock()
		srv.tokenCache.Token = ""
		srv.tokenCache.Unlock()

		err = errors.New("expires_in too large: " + strconv.FormatInt(result.ExpiresIn, 10))
		return
	case result.ExpiresIn > 60*60:
		result.ExpiresIn -= 60 * 10
	case result.ExpiresIn > 60*30:
		result.ExpiresIn -= 60 * 5
	case result.ExpiresIn > 60*5:
		result.ExpiresIn -= 60
	case result.ExpiresIn > 60:
		result.ExpiresIn -= 10
	default:
		srv.tokenCache.Lock()
		srv.tokenCache.Token = ""
		srv.tokenCache.Unlock()

		err = errors.New("expires_in too small: " + strconv.FormatInt(result.ExpiresIn, 10))
		return
	}

	// 更新 tokenGet 信息
	srv.tokenGet.LastTokenInfo = result.accessTokenInfo
	srv.tokenGet.LastTimestamp = timeNowUnix

	// 更新缓存
	srv.tokenCache.Lock()
	srv.tokenCache.Token = result.accessTokenInfo.Token
	srv.tokenCache.Unlock()

	token = result.accessTokenInfo
	return
}