Ftp cd command fails

Question

I have the following code which works with MS FTP service (IIS on XP) but fails against Unix and Maiframe FTP server implementaions.
String ftp = "ftp://id:[email protected]/1/2/3/file.txt;type=i";
FileInputStream fis = new FileInputStream(file);
byte[] data = new byte[fis.available ()];
fis.read ( data );
fis.close();
// ftp the file
URL ftpUrl = new URL(ftp);
URLConnection urlCon = ftpUrl.openConnection();
urlCon.setDoOutput (true);
// works fine against MS IIS 5.3 FTP Service; throws exception below on Unix SunOS 5.8 and mainframe ftp servers
OutputStream os = urlCon.getOutputStream();
os.write ( data );
os.close ();
java.io.FileNotFoundException: CWD 1: 550 1: No such file or directory.
        at sun.net.ftp.FtpClient.readReply(FtpClient.java:230)
        at sun.net.ftp.FtpClient.issueCommand(FtpClient.java:187)
        at sun.net.ftp.FtpClient.issueCommandCheck(FtpClient.java:200)
        at sun.net.ftp.FtpClient.cd(FtpClient.java:589)
        at sun.net.www.protocol.ftp.FtpURLConnection.cd(FtpURLConnection.java:243)
        at sun.net.www.protocol.ftp.FtpURLConnection.getOutputStream(FtpURLConnection.java:366)
        at com.db.cinq.purge.Cinqpj.ftpFiles(Cinqpj.java:957)
        at com.db.cinq.purge.Cinqpj.main(Cinqpj.java:119)
/* manual ftp works fine
H:\>ftp host.com
Connected to host.com.
220 host.com FTP server (Version 4.1 Mon Mar 23 10:20:45 CST 1998) ready.
User (10.140.137.39:(none)): id
331 Password required for id.
Password:
230 User id logged in.
ftp> cd /1/2/3
250 CWD command successful.
ftp> ls
200 PORT command successful.
*/Would greatly appreciate anyone's help.

Answer 1

I have tried
cd 1
cd 2
cd 3via XP ftp client and it is working fine. So I assume this is what Java class does after parsing FTP url.
Could you please elaborate on your statement "Not only that, it looks as if may not be doing
cd /1 as you might expect, and this could be a problem if your user account has a default working directory assigned by the FTP server. "
As you pointed out, it might be something related to FTP home directory.