获取当前APP签名

public String getSHA1Signature(Context context) {
        try {
            PackageInfo info = context.getPackageManager().getPackageInfo(context.getPackageName(), PackageManager.GET_SIGNATURES);

            byte[] cert = info.signatures[0].toByteArray();

            MessageDigest md = MessageDigest.getInstance("SHA1");
            byte[] publicKey = md.digest(cert);
            StringBuilder hexString = new StringBuilder();
            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);
                hexString.append(":");
            }
            return hexString.toString();
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return null;
    }