windows防火墙linuxftp操作文件FTPClient下载文件，本地Windows可以下载、删除，但是放到Linux服务器上就报错，
已经设置为被动模式了，还会是防火墙问题吗？
ftp.retrieveFileStream(file)在这个地方报错，错误信息如下：
[20170809 09:09:58.029] java.net.PlainSocketImpl.socketConnect(Native Method)
[20170809 09:09:58.029] java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
[20170809 09:09:58.029] java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
[20170809 09:09:58.029] java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
[20170809 09:09:58.029] java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
[20170809 09:09:58.029] java.net.Socket.connect(Socket.java:529)
[20170809 09:09:58.029] java.net.Socket.connect(Socket.java:478)
[20170809 09:09:58.029] java.net.Socket.(Socket.java:375)
[20170809 09:09:58.029] java.net.Socket.(Socket.java:189)
[20170809 09:09:58.029] org.apache.commons.net.DefaultSocketFactory.createSocket(DefaultSocketFactory.java:53)
[20170809 09:09:58.029] org.apache.commons.net.ftp.FTPClient._openDataConnection_(FTPClient.java:513)
[20170809 09:09:58.029] org.apache.commons.net.ftp.FTPClient.retrieveFileStream(FTPClient.java:1342)
