Using Cipher on table data

Question

God Morning. I did solve the hash password part. And I have now learned that a password is never decrypt. My new goal is to encrypt the data that is sent from JTable before it is saved. Then read it, decrypt and put it back to table. I have come up with the code below. And I just want to ask if it is safe to use for that purpose.
public void useCipher(byte[] string) throws Exception{
       KeyGenerator key = KeyGenerator.getInstance("DES");
       SecretKey secretKey = key.generateKey();
       Cipher cipher = Cipher.getInstance("DES");
       cipher.init(Cipher.ENCRYPT_MODE, secretKey);
       byte[] encrypted = cipher.doFinal(string);
       cipher.init(Cipher.DECRYPT_MODE, secretKey);
       byte[] decrypted = cipher.doFinal(encrypted);
       String cleartext = new String(decrypted);
    }

Answer 1

It all depends on your objective - are you doing this as an exercise for a school project? If so, you really need to read the book referenced in this thread.
Are you doing this for compliance to some regulation (such as PCI-DSS, 201 CMR 17.00, etc.)? If so, the problem isn't as simple as you think it is (Heartland Payment Systems just settled with Visa for US $60M for having breached credit card numbers despite being certified as compliant with the PCI's Data Security Standard; you can bet they are now spending millions of dollars on trying to encrypt their data and protect their keys better than they did so far).
Are you doing this to comply with some internal security policy that isn't mandated by external regulation? If so, you need to understand the threats you are protecting the system from, and then design in the solution components to mitigate the threats. If these threats have not been identified, you should hire a competent security consultant to identify them for you. Once identified, the choice of solutions - and thus the focus of your attention - becomes easier.
You are on a cryptography forum, MagnusT76, so a statement like "Don't need high level of security on it" is contradictory to why cryptography is used by people. The use of cryptography (encryption, digital signatures, etc.) is the penultimate line of defense in data-protection. The only other defensive position you can take to protect data (beyond the use of cryptography) is to eliminate it from the application or system completely.