(Java) File Existence Check

Testing to see if a file exists on the FTP server. The GetSizeByName method is a convenient way to check if a file exists. It will return -1 if the file does not exist, otherwise it returns the size of the file in bytes.

Chilkat Java Downloads Java Libs for Windows, MacOS, Linux, Alpine Linux, Solaris Java Libs for Android

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkFtp2 ftp = new CkFtp2();

    ftp.put_Hostname("ftp.example.com");
    ftp.put_Username("username");
    ftp.put_Password("password");

    // Connect and login to the FTP server.
    boolean success = ftp.Connect();
    if (success != true) {
        System.out.println(ftp.lastErrorText());
        return;
        }

    // Set the current remote directory to where the file is located:
    success = ftp.ChangeRemoteDir("something");
    if (success != true) {
        System.out.println(ftp.lastErrorText());
        return;
        }

    // Test to see if the file exists by getting the file size by name. 
    // If a -1 is returned, the file does not exist.
    int fileSize = ftp.GetSizeByName("test123.txt");
    if (fileSize < 0) {
        System.out.println("file does not exist");
        }
    else {
        System.out.println("file exists and is " + fileSize + " bytes in size");
        }

    success = ftp.Disconnect();
  }
}