无法使用API​​ - node.js从Google云端硬盘下载文件

时间:2015-03-26 10:55:46

标签: javascript node.js google-drive-api

我正在尝试使用 Google SDK API 使用node.js从谷歌驱动器下载文件。

但是我无法在服务器端写入/保存文件 - node.js

代码: -

var GoogleTokenProvider = require("refresh-token").GoogleTokenProvider,
    async = require('async'),
    fs = require("fs"),
    request = require('request'),
    _accessToken;

var _XMLHttpRequest = require("xmlhttprequest").XMLHttpRequest;
var https = require('https');

const CLIENT_ID = "";
const CLIENT_SECRET = "";
const REFRESH_TOKEN = '';
const ENDPOINT_OF_GDRIVE = 'https://www.googleapis.com/drive/v2';

async.waterfall([
        //-----------------------------
        // Obtain a new access token
        //-----------------------------
        function(callback) {
            var tokenProvider = new GoogleTokenProvider({
                'refresh_token': REFRESH_TOKEN,
                'client_id': CLIENT_ID,
                'client_secret': CLIENT_SECRET
            });
            tokenProvider.getToken(callback);
        },

        //--------------------------------------------
        // Retrieve the children in a specified folder
        // 
        // ref: https://developers.google.com/drive/v2/reference/files/children/list
        //-------------------------------------------
        function(accessToken, callback) {
            _accessToken = accessToken;
            request.get({
                'url': ENDPOINT_OF_GDRIVE + '/files?' + "q='root' in parents  and (mimeType = 'application/vnd.openxmlformats-officedocument.wordprocessingml.document')",
                'qs': {
                    'access_token': accessToken
                }
            }, callback);
        },

        //----------------------------
        // Parse the response
        //----------------------------
        function(response, body, callback) {
            var list = JSON.parse(body);
            if (list.error) {
                return callback(list.error);
            }
            callback(null, list.items[0]);
        },

        //-------------------------------------------
        // Get the file information of the children.
        //
        // ref: https://developers.google.com/drive/v2/reference/files/get
        //-------------------------------------------
        function(children, callback) {

            var xhr = new _XMLHttpRequest();
            xhr.open('GET', children.downloadUrl);
            xhr.setRequestHeader('Authorization', 'Bearer ' + _accessToken);
            xhr.onload = function() {
                console.log("xhr.responseText", xhr.responseText)
                fs.writeFile("download.docx", xhr.responseText)
                callback(xhr.responseText);
            };
            xhr.onerror = function() {
                callback(null);
            };
            xhr.send();
        }
    ],
    function(err, results) {
        if (!err) {
            console.log(results);
        }
    });

我在控制台中获取此信息: -     xhr.responseText的内容类似于

��▬h��↕E6M��~��3�3∟�9�� � �►��/2�:���♂�4��]�♀I�R���►
$SB6Q���c↔��H�=;+
���►q�3Tdכ��@!T��hEl_�|�I�↨��h(�^:▬�[h̓D♠��f���♠*���ݾ��M→
�1⌂♦"N�↑�o�]�7U$��A6����♠�W��k`�f▬♫��K�Z�^‼�0{<Z�▼�]F�����

                             ���J♥A♀��♣�a�}7�
"���H�w"�♥���☺w♫̤ھ�� �P�^����O֛���;�<♠�aYՠ؛`G�kxm��PY�[��g
Gΰino�/<���<�1��ⳆA$>"f3��\�ȾT��∟I S�������W♥����Y

请帮助我了解我从Drive Api获取的数据的格式是什么,并以哪种格式编写,以便我获得完整的 .docx 文件

修改

如果它有助于我下载文件(.docx),我可以使用 xmlRequest 以外的任何方法。

3 个答案:

答案 0 :(得分:10)

似乎

node-XMLHttpRequest不支持二进制下载 - 请参阅this issue。您所看到的是文件的二进制内容转换为String,在JavaScript中,它是二进制数据的不可逆和破坏性过程(这意味着您无法将字符串转换回缓冲区并获取与原始内容相同的数据)。

使用request,您可以通过以下方式下载二进制文件:

var request = require('request')
  , fs = require('fs')

request.get(
  { url: 'your-file-url'
  , encoding: null    // Force Request to return the data as Buffer
  , headers:
    { Authorization: 'Bearer ' + accessTokenHere
    }
  }
, function done (err, res) {
    // If all is well, the file will be at res.body (buffer)
    fs.writeFile('./myfile.docx', res.body, function (err) {
      // Handle err somehow
      // Do other work necessary to finish the request
    })
  }
)

注意:这会将整个文件缓存到内存中,然后才能保存到磁盘。对于小文件,这很好,但对于较大的文件,您可能希望将其实现为流式下载。 This SO question已经回答了这个问题,我建议你看看。

有关如何授权请求的详细信息,请访问Google Developers docs

答案 1 :(得分:2)

完整的工作示例:从Google云端硬盘下载文件 - Node.js API

var GoogleTokenProvider = require("refresh-token").GoogleTokenProvider,
    async = require('async'),
    fs = require("fs"),
    request = require('request'),
    _accessToken;

const CLIENT_ID = "";
const CLIENT_SECRET = "";
const REFRESH_TOKEN = '';
const ENDPOINT_OF_GDRIVE = 'https://www.googleapis.com/drive/v2';

async.waterfall([
        //-----------------------------
        // Obtain a new access token
        //-----------------------------
        function(callback) {
            var tokenProvider = new GoogleTokenProvider({
                'refresh_token': REFRESH_TOKEN,
                'client_id': CLIENT_ID,
                'client_secret': CLIENT_SECRET
            });
            tokenProvider.getToken(callback);
        },

        //--------------------------------------------
        // Retrieve the children in a specified folder
        // 
        // ref: https://developers.google.com/drive/v2/reference/files/children/list
        //-------------------------------------------
        function(accessToken, callback) {
            _accessToken = accessToken;
            request.get({
                'url': ENDPOINT_OF_GDRIVE + '/files?' + "q='root' in parents  and (mimeType = 'application/vnd.openxmlformats-officedocument.wordprocessingml.document')",
                'qs': {
                    'access_token': accessToken
                }
            }, callback);
        },

        //----------------------------
        // Parse the response
        //----------------------------
        function(response, body, callback) {
            var list = JSON.parse(body);
            if (list.error) {
                return callback(list.error);
            }
            callback(null, list.items);
        },

        //-------------------------------------------
        // Get the file information of the children.
        //
        // ref: https://developers.google.com/drive/v2/reference/files/get
        //-------------------------------------------
        function(children, callback) {

            for(var i=0;i<children.length;i++) {
                var file = fs.createWriteStream(children[i].title);
                // Downnload and write file from google drive
                (function(child) {
                    request.get(
                      { url: child.downloadUrl
                      , encoding: null    // Force Request to return the data as Buffer
                      , headers:
                        { Authorization: 'Bearer ' + _accessToken
                        }
                      }
                    , function done (err, res) {
                        res.pipe(file)
                        // If all is well, the file will be at res.body (buffer)
                        fs.writeFile('./' + child.title, res.body, function (err) {
                            if(!err) {
                                console.log('done')
                            } else {
                                console.log(err)
                            }
                          // Handle err somehow
                          // Do other work necessary to finish the request
                        })
                      }
                    )

                })(children[i])
            }
        }
    ],
    function(err, results) {
        if (!err) {
            console.log(results);
        }
    });

答案 2 :(得分:2)

我刚刚遇到了这方面的问题,我已经提供了一个示例,说明了如何使用Google API Node.js库实现这一功能:https://gist.github.com/davestevens/6f376f220cc31b4a25cd