(Android™) Encrypt Already Existing Zip

To encrypt an already existing non-encrypted .zip, the application must open the .zip, set the encryption related properties, and then re-write.

Chilkat Android™ Downloads Android™ Java Libraries Android C/C++ Libraries

// 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);

    // This requires the Chilkat Zip API to have been previously unlocked.
    // See Unlock Chilkat Zip for sample code.

    CkZip zip = new CkZip();

    // Open an unencrypted .zip
    boolean success = zip.OpenZip("qa_data/zips/test.zip");
    if (success != true) {
        Log.i(TAG, zip.lastErrorText());
        return;
        }

    // Unzip to a temp directory.
    int numFilesUnzipped = zip.Unzip("qa_output/tmp");
    if (numFilesUnzipped < 0) {
        Log.i(TAG, zip.lastErrorText());
        return;
        }

    // Clear the zip object.
    zip.NewZip("qa_output/aesTest.zip");

    // Indicate that 128-bit AES encryption is to be used when writing the .zip
    zip.put_Encryption(4);
    zip.put_EncryptKeyLength(128);

    // Set the password.
    zip.put_EncryptPassword("secret");

    // Append the files.
    zip.put_AppendFromDir("qa_output/tmp");
    success = zip.AppendFiles("*.*",true);
    if (success != true) {
        Log.i(TAG, zip.lastErrorText());
        return;
        }

    // Write the .zip and close it.
    success = zip.WriteZipAndClose();
    if (success != true) {
        Log.i(TAG, zip.lastErrorText());
        return;
        }

    Log.i(TAG, "Success.");

  }

  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."
  }
}