(Java) Determine if a Zip is Encrypted or Password-Protected

Determins whether or not a zip archive is AES encrypted or password-protected.

 Chilkat Java Library Downloads for Windows, Linux, and MAC OS X

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();

    boolean success;

    //  Any string unlocks the component for the 1st 30-days.
    success = zip.UnlockComponent("Anything for 30-day trial");
    if (success != true) {
        System.out.println(zip.lastErrorText());
        return;
    }

    //  An encrypted or password-protected zip can be opened
    //  without specifying the password.  However, the contents
    //  of the files cannot be unzipped without providing the correct
    //  password.

    success = zip.OpenZip("something.zip");
    if (success != true) {
        System.out.println(zip.lastErrorText());
        return;
    }

    //  If the zip is password-protected, meaning that it uses
    //  the old (insecure) Zip 2.0 encryption, then the
    //  PasswordProtect property will be true
    boolean bPwdProt;
    bPwdProt = zip.get_PasswordProtect();
    if (bPwdProt) {
        System.out.println("This zip is password-protected.");
    }

    //  If the zip is AES encrypted (WinZip compatible) then
    //  the Encryption property will be equal to 4.
    int encValue;
    encValue = zip.get_Encryption();
    if (encValue == 4) {
        System.out.println("This zip is AES encrypted.");
    }

    //  If the Encryption property = 0, then the zip is NOT
    //  strong encrypted, and is either password-protected or
    //  entirely unencrypted, depending on the value of the
    //  PasswordProtect property.

    //  If the Encryption property = 1, 2, or 3, then the zip was
    //  encrypted using AES, Blowfish, or Twofish using a
    //  Chilkat-specific encryption format that was implemented
    //  prior to the publication of the Zip AES standard.

    zip.CloseZip();
  }
}