HELP: Java running ftp from xp to linux

[achana chan]

Hi, I've a rather perplexing situation.
My Java program has a loop which tests whether a file exists on Linux and if it does, then ftp the file back from Linux to WindowsXP(sp2).
The problem is, if the file does not exist on Linux, ft creates a zero length file on XP which is misleading to XP and must be deleted. However we cannot delete it because ftp seems to have locked the file.
Following is stub code for the loop:

while(!GetOK(myIterator))
{    // this really does nothing other then loops until true 
}

And this is the code which ftps the GetOK test file back from Linux:

boolean GetOK(Iterator myIterator)
{
         boolean bOkForNextOne=false;
         try
         {
            int size=-1;
            while(!bOkForNextOne)
              ExecuteFtpCommands("GetOK.ftp");
              File f = new File(pParser.getDIR2() + "OK_for_next_one");
              if(f.exists())
              {
                      // make sure there is something in the file ie not zero length
                FileInputStream fin = new FileInputStream(f);
                fin.close();
                size = fin.available();  //for they byte array!
              }
              if (size < 1) 
              {
                  // LV2BONOVA.out.println(f.getAbsolutePath() +" size: " + size + " f.delete() " + f.delete());
 
                  f.delete(); // HERE: I cannot seem to delete the file because it is locked
                  LV2BONOVA.out.println("Did not get OK_for_next_one will sleep now for 60 seconds.");
                  try{java.lang.Thread.sleep(60*1000);}catch(InterruptedException ie){;}
                  continue;
              }
              if(f.exists() )
              {
                   // f.delete();
                   bOkForNextOne=true;
                   ExecuteFtpCommands("DelOKFromNOVA-ftp.txt","ftp_log.txt");
                   //ExecuteFtpCommands("DelOKFromNOVA-ftp.txt");
              }
              else
              {
                try
                {
                  java.lang.Thread.sleep(15 * 1000);
                }catch(InterruptedException ie){;}
              }
            }//while
        }
        catch(Exception e)
        {
            e.printStackTrace();
            try{java.lang.Thread.sleep(15 * 1000);}catch(InterruptedException ie){;}
            LV2BONOVA.out.println("Error in getting OK_for_next_one " + e.toString());
        }
        return bOkForNextOne;
  }

Here is the method for executing the ftp, the ftp commands are in a text file

void ExecuteFtpCommands(String  cmdFileName)
{
Date rightNow = new Date();
SimpleDateFormat formatter = new SimpleDateFormat("yyMMddHHmm");
String str_dts = formatter.format(rightNow);
if(carryOn == true)
{
  Process prc = null;
  Runtime rt = null;
  try
  {
    String logFile = logFileName;
    String command ="cmd /c ftp -v -s:" +cmdFileName;
    rt = Runtime.getRuntime();
    prc = rt.exec(command);
    brin = new BufferedReader(new InputStreamReader(prc.getInputStream()));
    String oneLine;
    while((oneLine = brin.readLine()) != null) LV2BONOVA.out.println(oneLine);
  }
  catch(Exception exc)
  {
    LV2BONOVA.out.println("\nError: ftp exception!");
    LV2BONOVA.out.println("Message   : " + exc.getMessage());
  }
}

Here is the ftp commands in the text file

open myserver
username
password
verbose
lcd C:\path\to\target\dir
cd path/to/OKFile/on/linux
ascii
prompt
get OK_for_next_one
bye

This generates the runtime error:
java.io.IOExceptiob: Bad file descriptor
.....at java.io.FileInputStream.available(Native Method)
.....at UseFTP.GetOK(UseFTP.java:552)
.....at UseFTP.Initialize(UseFTP.java:127)
.....at UseFTP.<init>(UseFTP:30)
.....at GetFiles.main(GetFiles.java:32)

The odd thing is when I crash out of the program UseFTP with a CTRL-C, the proper OKFile is ftp-ed back from Linux, overwriting the dud, zero length, OKFile created by ftp.
Any help greatly appreciated.

[Stephen Huey]

Can't you check in Java before FTPing the file whether it's a 0-length file or not? If not, can't you run a cleanup program right after this one exits to see whether or not any 0-length files were created and delete them? I mean, if the file lock is being held by that other program, then you'll just have to wait until it releases the file.