(Java) Async FTP Progress Info

Demonstrates checking for progress info updates when running a task asynchronously. This example demonstrates an FTP download.

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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 assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkFtp2 ftp = new CkFtp2();

    ftp.put_Hostname("ftp.someFtpServer.com");
    boolean success = ftp.ConnectOnly();
    if (success != true) {
        System.out.println(ftp.lastErrorText());
        return;
        }

    ftp.put_Username("myLogin");
    ftp.put_Password("myPassword");
    success = ftp.LoginAfterConnectOnly();
    if (success != true) {
        System.out.println(ftp.lastErrorText());
        return;
        }

    // Change to the remote directory where the file is located.
    // This step is only necessary if the file is not in the root directory
    // for the FTP account.
    success = ftp.ChangeRemoteDir("someRemoteDirectory");
    if (success != true) {
        System.out.println(ftp.lastErrorText());
        return;
        }

    String localFilename = "/temp/romeo.xml";
    String remoteFilename = "romeo.xml";

    // --------------------
    // Download a file
    // --------------------

    // Call the async version of the GetFile method to return a task object.
    // The task object is loaded, but is in the Inert state -- meaning it is
    // not yet scheduled to run on Chilkat's background thread pool.
    CkTask task = ftp.GetFileAsync(remoteFilename,localFilename);
    if (ftp.get_LastMethodSuccess() == false) {
        System.out.println(ftp.lastErrorText());
        return;
        }

    // Before starting the task, tell it to keep an in-memory log of what would've been
    // ProgressInfo callbacks.
    task.put_KeepProgressLog(true);

    // Schedule the task for running on the thread pool.  This changes the task's state
    // from Inert to Live.
    success = task.Run();
    if (success != true) {
        System.out.println(task.lastErrorText());

        return;
        }

    // The application is now free to do anything else
    // while the file is being downloaded.

    // For this example, we'll simply sleep and periodically
    // check to see if the download is finished, and report the progress
    // along the way.
    int curPctDone = 0;
    String name;
    String value;

    while (task.get_Finished() != true) {

        if (task.get_PercentDone() != curPctDone) {
            curPctDone = task.get_PercentDone();
            System.out.println(curPctDone + " percent done");
            }

        // Check the progress info log.
        // Emit any log entries..
        while ((task.get_ProgressLogSize() > 0)) {
            // Get the 1st entry, emit it, and then remove it..
            name = task.progressInfoName(0);
            value = task.progressInfoValue(0);

            // Entries reporting the received byte count will have the name "RcvByteCount"
            // Entries reporting the current bytes-per-second will have the name "RcvBytesPerSec"

            System.out.println(name + ": " + value);
            task.RemoveProgressInfo(0);
            }

        // Sleep 100 ms.
        task.SleepMs(100);

        }

    // Just in case there are any remaining entries...
    while ((task.get_ProgressLogSize() > 0)) {
        // Get the 1st entry, emit it, and then remove it..
        name = task.progressInfoName(0);
        value = task.progressInfoValue(0);
        System.out.println(name + ": " + value);
        task.RemoveProgressInfo(0);
        }

    // A finished task could be one that was canceled, aborted, or truly finished.  

    // If the task was "canceled", it was canceled prior to actually starting.  This could
    // happen if the task was canceled while waiting in a thread pool queue to be scheduled by Chilkat's
    // background thread pool scheduler.  

    // If the task was "aborted", it indicates that it was canceled while running in a background thread.  
    // The ResultErrorText will likely indicate that the task was aborted.

    // If the task "completed", then it ran to completion, but the actual success/failure of the method
    // is determined by the result obtained via a GetResult* method.  (A "completed" task will
    // have a StatusInt equal to 7.   If the task finished, but was not completed, then it must've
    // been aborted or canceled:
    if (task.get_StatusInt() != 7) {
        System.out.println("Task did not complete.");
        System.out.println("task status: " + task.status());

        return;
        }

    // The GetFile method returns a boolean.  Therefore, after the task is finished,
    // we can get the boolean result by calling GetResultBool.  This is the return value had
    // we called GetFile synchronously.
    success = task.GetResultBool();
    if (success != true) {
        // The task's ResultErrorText contains what would have been in the LastErrorText property had
        // the GetFile method been called synchronously.
        System.out.println(task.resultErrorText());
        }
    else {
        System.out.println("File downloaded asynchronously.");
        }

    success = ftp.Disconnect();
  }
}