Question

我无法从外部ftp-source下载数据以便在shinyapp中使用。 http://Shinyapps.io不允许写入服务器上的文件，因此我们必须避免这种情况，并尝试使用ftp进行外部保存，然后再将其直接读入内存。

请参阅https://stackoverflow.com/a/32631356/3493503的Wes Sauder了解我的起点。

library(RCurl)
a <- "test"
saveRDS(a, file="data.Rdata")

data_path <- my_data_path
url <- my_ftp_url
ftpUpload(data_path, to=url, connecttimeout=120) #upload

bin = getBinaryURL(url, verbose = TRUE,
               ftp.use.epsv = TRUE)
readRDS(rawConnection(bin))

上传工作正常，之后我可以用Filezilla下载文件并用readRDS读取。但是，尝试使用上面的代码在R中下载它不起作用：

 > library(RCurl)
    > a <- "test"
    > saveRDS(a, file="data.Rdata")
    > data_path <- "**************"
    > url <-"ftp://******************/results.RData"
    > ftpUpload(data_path, to=url, connecttimeout=120) #upload
    OK 
    0 
    > bin = getBinaryURL(url, verbose = TRUE,
    + ftp.use.epsv = TRUE)
    *   Trying ***.***.***.***...
    * Connected to ******************** port 21 (#0)
    < 220---------- Welcome to Pure-FTPd [privsep] [TLS] ----------
    < 220-You are user number 9 of 50 allowed.
    < 220-Local time is now 10:43. Server port: 21.
    < 220-This is a private system - No anonymous login
    < 220-IPv6 connections are also welcome on this server.
    < 220 You will be disconnected after 15 minutes of inactivity.
    > USER ********
    < 331 User ******** OK. Password required
    > PASS ********
    < 230 OK. Current restricted directory is /
    > PWD
    < 257 "/" is your current location
    * Entry path is '/'
    > EPSV
    * Connect data stream passively
    * ftp_perform ends with SECONDARY: 0
    < 229 Extended Passive mode OK (|||31331|)
    *   Trying ********...
    * Connecting to ******** port 31331
    * Connected to ******** port 21 (#0)
    > TYPE I
    < 200 TYPE is now 8-bit binary
    > SIZE results.RData
    < 213 50
    > RETR results.RData
    < 150 Accepted data connection
    * Maxdownload = -1
    * Getting file with size: 50
    * Remembering we are in dir ""
    < 226-File successfully transferred
    < 226 0.000 seconds (measured here), 0.66 Mbytes per second
    * Connection #0 to host ******** left intact
    > readRDS(rawConnection(bin))
    Error in readRDS(rawConnection(bin)) : unknown input format

为了完整性，我也试过

load(rawConnection(bin))
Error in load(rawConnection(bin)) : 
the input does not start with a magic number compatible with loading from a     connection

source(rawConnection(bin))
Error in source(rawConnection(bin)) : 
rawConnection(bin):1:1: unexpected input
1: 
   ^

非常感谢任何解决方案/解释/输入。

我通过包含RDS对象的Filezilla上传了一个文件到http://webkartet.no/data.Rdata供您试用。它会导致同样的错误。

注意：我试图跟进Wes Sauders答案的评论部分，但未能这样做，显然是由于缺乏SE点。试图在SO上找到解决方案但没有成功。

其他信息

平台x86_64-w64-mingw32
  拱x86_64
  os mingw32
  system x86_64，mingw32
  状态
  专业3   未成年人3.1
  2016年年   月06
  第21天   svn rev 70800
  语言R
  version.string R版本3.3.1（2016-06-21）   你头发中的昵称

使用Windows 7

通过ftp下载数据以在shinyapp中使用会导致readRDS未知输入格式错误

0 个答案: