import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;


/**
 * @Author: JCccc
 * @CreateTime: 2018-10-30
 * @Description:
 */
public class Md5Encrypt {

    private static final char[] DIGITS = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a',
            'b', 'c', 'd', 'e', 'f'};

    /**
     * 对字符串进行MD5加密
     *
     * @param text 明文
     * @return 密文
     */
    public static String md5(String text) {
        MessageDigest msgDigest = null;

        try {
            msgDigest = MessageDigest.getInstance("MD5");
        } catch (NoSuchAlgorithmException e) {
            throw new IllegalStateException("System doesn't support MD5 algorithm.");
        }

        try {
            msgDigest.update(text.getBytes("UTF-8")); // 注意该接口是按照指定编码形式签名

        } catch (UnsupportedEncodingException e) {

            throw new IllegalStateException("System doesn't support your  EncodingException.");

        }

        byte[] bytes = msgDigest.digest();

        String md5Str = new String(encodeHex(bytes));

        return md5Str;
    }

    private static char[] encodeHex(byte[] data) {

        int l = data.length;

        char[] out = new char[l << 1];
        // two characters form the hex value.
        for (int i = 0, j = 0; i < l; i++) {
            out[j++] = DIGITS[(0xF0 & data[i]) >>> 4];
            out[j++] = DIGITS[0x0F & data[i]];
        }

        return out;
    }
}
   /* public static void main(String[] args) {
        System.out.println(Md5Encrypt.md5(Md5Encrypt.md5("123456" + "ffff")));
    }

}
*/