Java 對稱加密解密

import java.security.Key;
import java.security.NoSuchAlgorithmException;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

import org.apache.commons.codec.binary.Base64;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class DESUtil {
    @SuppressWarnings("unused")
    private static final Logger logger = LoggerFactory.getLogger(DESUtil.class);
    public static final String KEY_ALGORITHM = "DES";
    public static final String CIPHER_ALGORITHM = "DES/ECB/PKCS5Padding";

    public static String initkey() throws NoSuchAlgorithmException {
        KeyGenerator kg = KeyGenerator.getInstance(KEY_ALGORITHM);
        kg.init(56);
        SecretKey secretKey = kg.generateKey();
        String confKey = Base64.encodeBase64String(secretKey.getEncoded());
        return confKey;
    }

    private static Key toKey(byte[] key) throws Exception {
        DESKeySpec dks = new DESKeySpec(key);
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(KEY_ALGORITHM);
        SecretKey secretKey = keyFactory.generateSecret(dks);
        return secretKey;
    }

    public static String encrypt(String data, String key) throws Exception {
        Key k = toKey(Base64.decodeBase64(key));
        Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
        cipher.init(Cipher.ENCRYPT_MODE, k);
        return Base64.encodeBase64String(cipher.doFinal(data.getBytes()));
    }

    public static String decrypt(String data, String key) throws Exception {
        Key k = toKey(Base64.decodeBase64(key));
        Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, k);
        return new String(cipher.doFinal(Base64.decodeBase64(data)));
    }
}