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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import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Ftp2;

public class ChilkatExample {

    public static void main(String[] args) {
        // 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.

        Ftp2 ftp = new Ftp2();

        ftp.setHostname("ftp.example.com");
        ftp.setUsername("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.setPassword("myPassword");

        try {
            ftp.connect();
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            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;
        try {
            ftp.largeFileUpload("qa_data/bigfile.zip", "uploads/bigfile.zip", chunkSize);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

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

        try {
            ftp.disconnect();
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }
    }
}