(Java) Open a Zip Archive

See more Zip Examples

Demonstrates how to open a zip, or an encrypted .zip, or a legacy password-protected .zip.

Chilkat Java Downloads Java Libs for Windows, MacOS, Linux, Alpine Linux, Solaris Java Libs for Android

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[])
  {
    CkZip zip = new CkZip();

    // Open a non-encrypted .zip
    boolean success = zip.OpenZip("qa_data/zips/sample.zip");
    if (success != true) {
        System.out.println(zip.lastErrorText());
        return;
        }

    System.out.println("Num entries = " + zip.get_NumEntries());

    // ...
    // ...

    zip.CloseZip();

    // ----------------------------------------------------------------------------
    // Open an encrypted zip...

    // The two main types of encryption used in ZIP archives are Password-Protected and AES.
    // 

    // ---------------------------------------
    // 1. Legacy Password-Protected Zip
    // 
    // This is the older and less secure method of encrypting ZIP archives. 
    // It provides a basic level of security, but is considered weak by modern standards. 
    // It is vulnerable to various attacks, including known-plaintext attacks and brute force attacks.
    // Although Chilkat allows it, you shouldn't create new zip archives using legacy password-protection.

    // ---------------------------------------
    // 2. AES Encrypted Zip
    // 
    // AES encryption is a more modern and secure method for encrypting ZIP archives. 
    // It provides strong encryption based on the AES algorithm, which is widely regarded as secure. 
    // AES supports different key lengths, typically 128-bit, 192-bit, and 256-bit.

    // When opening an encrypted zip, your application only needs to provide the correct password.
    // The information about the type of encryption and the key length (if AES) is already embedded within the encrypted .zip.

    // Provide the decrypt password because we are opening an existing .zip (decrypting)
    zip.put_DecryptPassword("thePassword");

    success = zip.OpenZip("qa_data/zips/encryptedSamples/ziptest_256.zip");
    if (success != true) {
        System.out.println(zip.lastErrorText());
        return;
        }

    System.out.println("Num entries = " + zip.get_NumEntries());

    // ...
    // ...

    zip.CloseZip();
  }
}