import java.io.UnsupportedEncodingException;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

public class AES {
    private static final String CipherMode = "AES/ECB/PKCS5Padding";
    public static String k = "sdtyffdftesfyfdw";

    private static SecretKeySpec createKey(String key) {
        byte[] bArr = null;
        if (key == null) {
            key = "";
        }
        StringBuffer sb = new StringBuffer(32);
        sb.append(key);
        while (sb.length() < 32) {
          sb.append("0");
        }
        if (sb.length() > 32) {
          sb.setLength(32);
        }
        try {
            bArr = sb.toString().getBytes("UTF-8");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return new SecretKeySpec(bArr, "AES");
    }

    public static byte[] encrypt(byte[] bArr, String key) {
        try {
            SecretKeySpec seckey = AES.createKey(key);
            System.out.println(seckey);
            Cipher instance = Cipher.getInstance(CipherMode);
            instance.init(Cipher.ENCRYPT_MODE, seckey);
            return instance.doFinal(bArr);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public static String encrypt(String str, String key) {
        byte[] bArr = null;
        try {
            bArr = str.getBytes("UTF-8");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return AES.byte2hex(AES.encrypt(bArr, key));
    }

    public static byte[] decrypt(byte[] bArr, String key) {
        try {
            SecretKeySpec seckey = AES.createKey(key);
            Cipher instance = Cipher.getInstance(CipherMode);
            instance.init(Cipher.DECRYPT_MODE, seckey);
            return instance.doFinal(bArr);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public static String decrypt(String str, String key) {
        byte[] bArr = null;
        try {
            bArr = AES.hex2byte(str);
        } catch (Exception e) {
            e.printStackTrace();
        }
        bArr = AES.decrypt(bArr, key);
        if (bArr == null) {
            return null;
        }
        try {
            return new String(bArr, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return null;
    }

    public static String byte2hex(byte[] bArr) {
        StringBuffer sb = new StringBuffer(bArr.length * 2);
        String hex = "";
        for (byte b : bArr) {
            hex = Integer.toHexString(b & 255);
            if (hex.length() == 1) {
                sb.append("0");
            }
            sb.append(hex);
        }
        return sb.toString().toUpperCase();
    }

    private static byte[] hex2byte(String hex) {
        if (hex == null || hex.length() < 2) {
            return new byte[0];
        }
        hex = hex.toLowerCase();
        int len = hex.length() / 2;
        byte[] bArr = new byte[len];
        for (int i = 0; i < len; i++) {
            bArr[i] = (byte) (Integer.parseInt(hex.substring(2 * i, (2 * i) + 2), 16) & 255);
        }
        return bArr;
    }
    
    public static void main(String[] args) {
      String s = AES.encrypt("13249582075", AES.k);
      System.out.println(s);
      
      s = AES.decrypt(s, k);
      System.out.println(s);
    }
}