Enkriptor AES With Secret-Key

package sonienkripsi;
 
import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Base64;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import javax.swing.*;
 
/**
 *
 * @author montox nox on Linux Mint source:
 * https://howtodoinjava.com/java/java-security/java-aes-encryption-example/
 */
public class NoxAES_WIthKey extends javax.swing.JFrame {
 
    String KalimatAsli, RumusEnkrip, RumusDekrip;
 
    private static SecretKeySpec secretKey;
    private static byte[] key;
 
    public static void setKey(final String myKey) {
        MessageDigest sha = null;
        try {
            key = myKey.getBytes("UTF-8");
            sha = MessageDigest.getInstance("SHA-1");
            key = sha.digest(key);
            key = Arrays.copyOf(key, 16);
            secretKey = new SecretKeySpec(key, "AES");
        } catch (NoSuchAlgorithmException | UnsupportedEncodingException e) {
            e.printStackTrace();
        }
    }
 
    public static String encrypt(final String strToEncrypt, final String secret) {
        try {
            setKey(secret);
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
            cipher.init(Cipher.ENCRYPT_MODE, secretKey);
            return Base64.getEncoder()
                    .encodeToString(cipher.doFinal(strToEncrypt.getBytes("UTF-8")));
        } catch (Exception e) {
            System.out.println("Error while encrypting: " + e.toString());
        }
        return null;
    }
 
    public static String decrypt(final String strToDecrypt, final String secret) {
        try {
            setKey(secret);
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
            cipher.init(Cipher.DECRYPT_MODE, secretKey);
            return new String(cipher.doFinal(Base64.getDecoder()
                    .decode(strToDecrypt)));
        } catch (Exception e) {
            System.out.println("Error while decrypting: " + e.toString());
        }
        return null;
    }
 
    /**
     * Creates new form NoxAES
     */
    public NoxAES_WIthKey() {
        initComponents();
        BtDekrip_.setVisible(false);
        jLabel4.setVisible(false);
    }      
 
    private void BtEnkrip_ActionPerformed(java.awt.event.ActionEvent evt) {                                          
        // TODO add your handling code here:
        KalimatAsli = TextASLI_.getText();
        final String secretKey = TextKunci_.getText();
        RumusEnkrip = NoxAES_WIthKey.encrypt(KalimatAsli, secretKey);
 
        if (TextASLI_.getText().equals("") || TextKunci_.getText().equals("")) {
            JOptionPane.showMessageDialog(null, "Maaf...!!!\nTeks Kalimat Asli atau Kata Kunci Rahasia\nbelum di isi...");
            TextASLI_.requestFocus();
        } else {
            TextAES_.setText(RumusEnkrip);
        }
    }                                         
 
    private void BtDekrip_ActionPerformed(java.awt.event.ActionEvent evt) {                                          
        // TODO add your handling code here:
        final String secretKey = TextKunci_.getText();
        RumusDekrip = NoxAES_WIthKey.decrypt(RumusEnkrip, secretKey);
    }                                         
 
    private void BtReset_ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        // TODO add your handling code here:
        TextASLI_.setText("");
        TextKunci_.setText("");
        TextAES_.setText("");
    }                                        
 
    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(NoxAES_WIthKey.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(NoxAES_WIthKey.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(NoxAES_WIthKey.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(NoxAES_WIthKey.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>
        //</editor-fold>
 
        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new NoxAES_WIthKey().setVisible(true);
            }
        });
    }
 
    // Variables declaration - do not modify                     
    private javax.swing.JButton BtDekrip_;
    private javax.swing.JButton BtEnkrip_;
    private javax.swing.JButton BtReset_;
    private javax.swing.JTextArea TextAES_;
    private javax.swing.JTextArea TextASLI_;
    private javax.swing.JTextField TextKunci_;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JLabel jLabel4;
    private javax.swing.JLabel jLabel5;
    private javax.swing.JLabel jLabel6;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JScrollPane jScrollPane2;
    private javax.swing.JScrollPane jScrollPane4;
    private javax.swing.JTextArea jTextArea1;
    // End of variables declaration                   
}