// 暗号化サンプル

String src = "abcxyz";
byte[] keydata; // 3DES鍵のbyte配列

DESedeKeySpec keySpec = new DESedeKeySpec(keydata);
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DESede");
SecretKey key = keyFactory.generateSecret(keySpec);
Cipher cipher = Cipher.getInstance(algorithm);

byte[] srcBytes = src.getBytes("EUC-JP");
cipher.init(Cipher.ENCRYPT_MODE, key);
byte[] encryptedBytes = cipher.doFinal(srcBytes);