FTPClient.exists(FileName) - Throws exception

Question

Hi,

When I use FTPClient.exists(FileName) instead of returning false if a file does not exist, FTPClient throws FTPException. Here is a sample code:

public class Test {

    private static Logger log = Logger.getLogger(Test.class);
    private static FTPClient ftp;
   
   public static void main(String[] args) throws Exception{
      
      Logger.setLevel(Level.ALL);
      ftp = new FTPClient();
      FTPMessageCollector listener = new FTPMessageCollector();
                ftp.setMessageListener(listener);
               
      try {

         ftp.setRemoteHost("x.x.x.x");
         ftp.setTimeout(61*1000);
         ftp.connect();
         ftp.login("xxx", "xxx");
         ftp.setConnectMode(FTPConnectMode.PASV);
         ftp.setType(FTPTransferType.BINARY);
         
                    
         File file = new File("D:\\programs\\test.exe");

                        // This file SHOULD NOT EXIST ON THE SERVER
         
                        if(ftp.exists(file.getName())==true){
            log.info("Oh No - File exist");
         }

         // Upload the file
         log.info("Uploading File");
                  
         ftp.put(file.toString(), file.getName());
                  
         ftp.quit();
         
         
      } catch (IOException e) {
         System.out.println("Main - IO Exception");
         e.printStackTrace();
      } catch (FTPException e) {
         System.out.println("Main - FTP Exception");
         e.printStackTrace();
      }

   }
   
}

Here is the DEBUG Output:

DEBUG [FTPClient] 28 Jun 2007 14:19:13.147 : Connecting to /x.x.x.x:21
DEBUG [SocketUtils] 28 Jun 2007 14:19:13.257 : Invoking connect with timeout=61000
DEBUG [FTPControlSocket] 28 Jun 2007 14:19:13.377 : 220 (vsFTPd 2.0.5)
DEBUG [FTPControlSocket] 28 Jun 2007 14:19:13.397 : ---> USER xxx
DEBUG [FTPControlSocket] 28 Jun 2007 14:19:13.417 : 331 Please specify the password.
DEBUG [FTPControlSocket] 28 Jun 2007 14:19:13.417 : ---> PASS ***
DEBUG [FTPControlSocket] 28 Jun 2007 14:19:13.457 : 230 Login successful.
DEBUG [FTPControlSocket] 28 Jun 2007 14:19:13.467 : ---> TYPE I
DEBUG [FTPControlSocket] 28 Jun 2007 14:19:13.477 : 200 Switching to Binary mode.
DEBUG [FTPControlSocket] 28 Jun 2007 14:19:13.477 : ---> SIZE test.exe
DEBUG [FTPControlSocket] 28 Jun 2007 14:19:13.527 : 550 Could not get file size.
DEBUG [FTPClient] 28 Jun 2007 14:19:13.527 : SIZE not supported - trying MDTM
DEBUG [FTPControlSocket] 28 Jun 2007 14:19:13.527 : ---> MDTM test.exe
DEBUG [FTPControlSocket] 28 Jun 2007 14:19:13.547 : 550 Could not get file modification time.
DEBUG [FTPClient] 28 Jun 2007 14:19:13.547 : MDTM not supported - trying RETR
DEBUG [FTPControlSocket] 28 Jun 2007 14:19:13.717 : ---> PORT 192,168,254,101,4,218
DEBUG [FTPControlSocket] 28 Jun 2007 14:19:13.727 : 200 PORT command successful. Consider using PASV.
DEBUG [FTPControlSocket] 28 Jun 2007 14:19:13.727 : ---> RETR test.exe
DEBUG [FTPControlSocket] 28 Jun 2007 14:19:13.747 : 550 Failed to open file.
WARN [FTPClient] 28 Jun 2007 14:19:13.747 : Unable to determine if file 'test.exe' exists.
Main - FTP Exception
com.enterprisedt.net.ftp.FTPException: Unable to determine if file 'test' exists.
at com.enterprisedt.net.ftp.FTPClient.exists(FTPClient.java:1473)
at Test.main(Test.java:52)

Thanks for helping!

Answer 1

This should do it - replace the appropriate class with the code below, and recompile:

final public class FileNotFoundStrings extends ServerStrings {

    /**
     * Server string indicating file not found
     */
    final public static String FILE_NOT_FOUND = "NOT FOUND";
    
    /**
     * Server string indicating file not found
     */
    final public static String NO_SUCH_FILE = "NO SUCH FILE";
    
    /**
     * Server string indicating file not found
     */
    final public static String FAILED_TO_OPEN = "FAILED TO OPEN FILE";
    
    /**
     * Server string indicating file not found
     */
    final public static String COULD_NOT_GET_FILE = "COULD NOT GET FILE";
    
    /**
     * Constructor. Adds the fragments to match on
     */
    public FileNotFoundStrings() {
        add(FILE_NOT_FOUND);
        add(NO_SUCH_FILE);
        add(FAILED_TO_OPEN);
        add(COULD_NOT_GET_FILE);
    }

}