Java

Upload a Large File in Chunks (FTP)

Demonstrates the Chilkat Ftp2.LargeFileUpload method, which uploads a local file as a sequence of transfers, each up to a given chunk size. The arguments are the local path, the remote path, and the chunk size in bytes.

Note: The local paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: Some servers, proxies, or firewalls impose a limit on the size or duration of a single data transfer, which a very large file can exceed. This method sidesteps that by sending the file in pieces — the first with STOR to create or replace the file, each subsequent one appended — so no single transfer is oversized. Choose a chunk size comfortably under whatever limit you are working around.

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Java

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[])
  {
    boolean success = false;

    //  Demonstrates the Ftp2.LargeFileUpload method, which uploads a local file as a sequence of
    //  transfers, each up to a given chunk size.  The 1st argument is the local path, the 2nd is the
    //  remote path, and the 3rd is the chunk size in bytes.

    CkFtp2 ftp = new CkFtp2();

    ftp.put_Hostname("ftp.example.com");
    ftp.put_Username("myFtpLogin");

    //  Normally you would not hard-code the password in source.  You should instead obtain it
    //  from an interactive prompt, environment variable, or a secrets vault.
    ftp.put_Password("myPassword");

    success = ftp.Connect();
    if (success == false) {
        System.out.println(ftp.lastErrorText());
        return;
        }

    //  The first chunk is sent with STOR (creating/replacing the remote file); each later chunk is
    //  appended.  Uploading in chunks can work around server or network limits on a single transfer.
    int chunkSize = 10485760;
    success = ftp.LargeFileUpload("qa_data/bigfile.zip","uploads/bigfile.zip",chunkSize);
    if (success == false) {
        System.out.println(ftp.lastErrorText());
        return;
        }

    System.out.println("Large file uploaded.");

    success = ftp.Disconnect();
    if (success == false) {
        System.out.println(ftp.lastErrorText());
        return;
        }
  }
}