Untitled

import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import java.io.*;

public class AES {
    public static String asHex(byte[] buf) {
        StringBuffer strbuf = new StringBuffer(buf.length * 2);
        for (byte b : buf) {
            if ((b & 0xff) < 0x10)
                strbuf.append("0");
            strbuf.append(Long.toString(b & 0xff, 16));
        }
        return strbuf.toString();
    }

    public static void main(String[] args) throws Exception {
        String message = "AES still rocks!!";

        // Get the KeyGenerator
        KeyGenerator kgen = KeyGenerator.getInstance("AES");
        kgen.init(128); // 192 and 256 bits may not be available

        // Generate the secret key specs.
        SecretKey skey = kgen.generateKey();
        byte[] raw = skey.getEncoded();
        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");

        // Instantiate the cipher
        Cipher cipher = Cipher.getInstance("AES");

        // Encrypt the message
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
        byte[] encrypted = cipher.doFinal((args.length == 0 ? message : args[0]).getBytes());
        System.out.println("Encrypted string: " + asHex(encrypted));

        // Decrypt the message
        cipher.init(Cipher.DECRYPT_MODE, skeySpec);
        byte[] original = cipher.doFinal(encrypted);
        String originalString = new String(original);
        System.out.println("Original string: " + originalString + " " + asHex(original));
    }
}