无法使用API-node.js从Google Drive下载文件

节点XMLHttpRequest似乎不支持二进制下载-请参阅此问题。您看到的是文件的二进制内容被转换为字符串，在JavaScript中，这对二进制数据来说是一个不可逆和破坏性的过程（这意味着您无法将字符串转换回缓冲区并获得与原始内容相同的数据）。

使用请求，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：这将在将整个文件保存到磁盘之前将其缓冲到内存中。对于小文件，这是可以的，但对于较大的文件，您可能需要考虑将其实现为流式下载。这个SO问题已经回答了这个问题，我建议你看看。

关于如何授权您的请求的更多信息可以在谷歌开发者文档中找到。

完整工作示例：从GoogleDrive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);
        }
    });

我刚刚遇到了这个问题，我已经包含了一个使用Google API Node.js库使其工作的示例：https://gist.github.com/davestevens/6f376f220cc31b4a25cd