SHA1的获取方法

public static String sHA1(Context context) {
        try {
            PackageInfo info = context.getPackageManager().getPackageInfo(
                    context.getPackageName(), PackageManager.GET_SIGNATURES);
            byte[] cert = info.signatures[0].toByteArray();
            MessageDigest md = null;
            try {
                md = MessageDigest.getInstance("SHA1");
            } catch (NoSuchAlgorithmException e) {
                e.printStackTrace();
            }
            byte[] publicKey = md.digest(cert);
            StringBuffer hexString = new StringBuffer();
            for (int i = 0; i < publicKey.length; i++) {
                String appendString = Integer.toHexString(0xFF & publicKey[i])
                        .toUpperCase(Locale.US);
                if (appendString.length() == 1) {
                    hexString.append("0");
                }
                hexString.append(appendString);
            }
            StringBuilder stringBuilder = new StringBuilder();
            for (int i = 0; i < hexString.length(); i += 2) {
                stringBuilder.append(hexString.subSequence(i, i + 2))
                        .append(":");
            }
            return stringBuilder.substring(0, stringBuilder.length() - 1);
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
        return null;
    }