Java之 SHA1 与MD5加密

一、SHA1加密　

/*
     * SHA1加密，结果为小写
     */
    public static String SHA1(String decript) {
        try {
            MessageDigest digest = java.security.MessageDigest
                    .getInstance("SHA-1");
            digest.update(decript.getBytes());
            byte messageDigest[] = digest.digest();
            // Create Hex String
            StringBuffer hexString = new StringBuffer();
            // 字节数组转换为 十六进制 数
            for (int i = 0; i < messageDigest.length; i++) {
                String shaHex = Integer.toHexString(messageDigest[i] & 0xFF);
                if (shaHex.length() < 2) {
                    hexString.append(0);
                }
                hexString.append(shaHex);
            }
            return hexString.toString();

        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return "";
    }

二、MD5加密

/**
     * MD5加密
     */
    public String md5s(String plainText) {
        String str = "";
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            md.update(plainText.getBytes());
            byte b[] = md.digest();

            int i;

            StringBuffer buf = new StringBuffer("");
            for (int offset = 0; offset < b.length; offset++) {
                i = b[offset];
                if (i < 0)
                    i += 256;
                if (i < 16)
                    buf.append("0");
                buf.append(Integer.toHexString(i));
            }
            str = buf.toString();
            System.out.println("result: " + buf.toString());// 32位的加密
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return str;
    }