DES加密解密

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import java.security.SecureRandom;

public class DESUtil {

    private static Cipher getDES(String key, boolean b) throws Exception {
        SecureRandom sr = new SecureRandom();
        DESKeySpec dks = new DESKeySpec(key.getBytes());
        SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("DES");
        SecretKey skey = keyfactory.generateSecret(dks);
        Cipher cipher = Cipher.getInstance("DES");
        if (b) {  // 加密
            cipher.init(Cipher.ENCRYPT_MODE, skey, sr);
        } else {  //解密
            cipher.init(Cipher.DECRYPT_MODE, skey, sr);
        }

        return cipher;
    }

    /**
     * 加密
     *
     * @param txt
     * @param key
     * @return
     * @author 张九怀
     * @email zjh1983314@163.com
     */
    public static String encrypt(String txt, String key) {
        String r = null;
        try {
            Cipher cipher = getDES(key, true);
            byte[] b = cipher.doFinal(txt.getBytes());
            r = byte2hex(b);

        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
        return r;

    }

    /**
     * 解密
     *
     * @param d
     * @param key
     * @return
     * @author 张九怀
     * @email zjh1983314@163.com
     */
    public static String decrypt(String d, String key) {
        String r = null;
        try {
            Cipher cipher = getDES(key, false);
            byte[] b = cipher.doFinal(hex2byte(d));
            r = new String(b);
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
        return r;
    }

    private static byte[] hex2byte(String d) throws IllegalArgumentException {
        if (d.length() % 2 != 0) {
            throw new IllegalArgumentException();
        }
        char[] arr = d.toCharArray();
        byte[] b = new byte[d.length() / 2];
        for (int i = 0, j = 0; i < d.length(); i++, j++) {
            String wap = "" + arr[i++] + arr[i];
            int byteint = Integer.parseInt(wap, 16) & 0xFF;
            b[j] = new Integer(byteint).byteValue();
        }
        return b;
    }

    /**
     * byte 转 16进制
     *
     * @param b
     * @return
     * @author 张九怀
     * @email zjh1983314@163.com
     */
    private static String byte2hex(byte[] b) {
        StringBuffer sb = new StringBuffer();
        for (int n = 0; n < b.length; n++) {
            String stmp = (Integer.toHexString(b[n] & 0XFF));
            if (stmp.length() == 1) {
                sb.append("0" + stmp);
            } else {
                sb.append(stmp);
            }
        }
        return sb.toString();
    }

}