Folder Encryption Not Working (Demo Included)

Question

This simple folder encryption/compression fails. The folder only contains a child folder and text file, yet encryption returns false. Any idea why?

import net.lingala.zip4j.ZipFile;
import net.lingala.zip4j.exception.ZipException;
import net.lingala.zip4j.model.ZipParameters;
import net.lingala.zip4j.model.enums.AesKeyStrength;
import net.lingala.zip4j.model.enums.CompressionLevel;
import net.lingala.zip4j.model.enums.CompressionMethod;
import net.lingala.zip4j.model.enums.EncryptionMethod;
import java.io.File;

public class Demo_ZipEncryptFolderOnly {
    public static void main(String[] args) throws ZipException {
        ZipParameters zipParameters = new ZipParameters();
        zipParameters.setEncryptFiles(true);
        zipParameters.setCompressionMethod(CompressionMethod.DEFLATE);
        zipParameters.setCompressionLevel(CompressionLevel.NORMAL);
        zipParameters.setEncryptionMethod(EncryptionMethod.AES);
        zipParameters.setAesKeyStrength(AesKeyStrength.KEY_STRENGTH_256);
        ZipFile zipFile = new ZipFile("C:\\Users\\me\\Desktop\\Folder.zip", "password".toCharArray());
        zipFile.addFolder(new File("C:\\Users\\me\\Desktop\\Folder"));
        System.out.println("Encrypted: "+zipFile.isEncrypted());
    }
}

Maven:

<dependency>
     <groupId>net.lingala.zip4j</groupId>
     <artifactId>zip4j</artifactId>
     <version>2.8.0</version>
</dependency>

Folder to Encrypt:

Answer 1

You forgot to pass zipParameters as second parameter in the zipFile.addFolder() call. If this is fixed, it works (s. also the zip4j docs):

zipFile.addFolder(new File("C:\\Users\\me\\Desktop\\Folder"), zipParameters);