Upload file to Google Drive

GoogleDriveWebService.java

public static void UploadFile(String fileName, String bodyEncoded, String contentType) {
        String fileExtension = fileName.substring(fileName.indexOf('.')+1, fileName.length());
        String boundary = '----WebKitFormBoundary7MA4YWxkTrZu0gW';
        String header = '\r\n--' + boundary + '\r\n';
        String footer = '\r\n--' + boundary + '--';
        String fileNameToUpload = fileName;//+'.'+fileExtension.trim();
        String folderId = '19xl6WOmqZIfLCukX4YskGqlQIRSZDzXc';
        List<String> listofFolderId = new List<String>();
        listofFolderId.add(folderId.trim());
        String body = header + 'Content-Type: application/json\r\n\r\n'
            +'{ "title" : "' + fileNameToUpload + '",' + '"parents": [{"kind": "drive#fileLink","id": "'+folderId+'"}]'+','
            + ' "mimeType" : "' + contentType + '" }' + header + 'Content-Type: ' + contentType
            + '\r\n' + 'Content-Transfer-Encoding: base64\r\n' + '\r\n' + bodyEncoded + footer;
        Http https = new Http();
        HttpRequest req = new HttpRequest();
        req.setEndpoint('callout:Google_Drive'+'/upload/drive/v2/files?uploadType=multipart');
        req.setHeader('Content-Type', 'multipart/mixed; boundary="' + boundary + '"');
        req.setHeader('Content-length', String.valueOf(body.length()));
        req.setBody(body);
        req.setMethod('POST');
        HttpResponse response = https.send(req);
        System.debug(' response '+response.getBody() );
    }