public DERObjectIdentifier( String  identifier)
DERObjectIdentifier( byte[]  bytes)
    public DERObjectIdentifier(        String  identifier)    {        for (int i = identifier.length() - 1; i >= 0; i--)        {            char ch = identifier.charAt(i);                        if ('0' <= ch && ch <= '9')            {                continue;            }                        if (ch == '.')            {                continue;            }                        throw new IllegalArgumentException("string " + identifier + " not an OID");        }                this.identifier = identifier;    }