关于ftpreader

我想同步ftp服务器上的文件到本地是否可行，如果可行的话支持哪些文件类型，在写的时候应该用哪个writer
ps：在读取ftp服务器上的txt文件时出现了空指针异常
com.alibaba.datax.common.exception.DataXException: Code:[UnstructuredStorageReader-11], Description:[出现运行时异常, 请 联系我们]. - 运行时错误, 请联系我们 - java.lang.NullPointerException

Start by locating the ftpreader implementation and the handling for TXT files, then reproduce the reported NullPointerException using the DataX error code [UnstructuredStorageReader-11]. Review how FTP input is mapped to a writer and document the supported file types and the conditions that trigger the exception. Done means the failure is reproduced and the supported usage or a confirmed fix is clearly documented.

Written by the indexing model from the issue text.