(Android™) Set a Custom Last-Modified Date in a Gzip File

See more Gzip Examples

This example demonstrates how to use the SetDt method to specify a custom last-modified date and time that will be embedded in a Gzip file.

A CkDateTime object is first initialized with a specific date/time using an RFC 822 formatted string. This date/time is then applied to the Gzip object using SetDt.

When a compression method is called (such as CompressStringToFile), the specified date/time is included in the Gzip metadata. This allows the resulting .gz file to carry a meaningful timestamp rather than using the current system time.

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// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    boolean success = false;

    // This example demonstrates how to set a custom last-modified date/time
    // that will be embedded in a Gzip file.

    CkGzip gzip = new CkGzip();
    CkDateTime dt = new CkDateTime();

    // Set the date/time using a timestamp format (ISO 8601 style):
    dt.SetFromTimestamp("2025-11-15T12:45:26-05:00");

    // Apply the date/time to the Gzip object:
    success = gzip.SetDt(dt);
    if (success == false) {
        Log.i(TAG, gzip.lastErrorText());
        return;
        }

    // Compress a string so the custom date/time is embedded in the .gz:
    String inputStr = "Example text for Gzip compression.";
    success = gzip.CompressStringToFile(inputStr,"utf-8","output.gz");
    if (success == false) {
        Log.i(TAG, gzip.lastErrorText());
        return;
        }

    Log.i(TAG, "Gzip file created with custom last-modified date.");

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}