private void close(Connection conn) throws SQLException {
        if (conn != null) {
            if (conn.isReadOnly()) {
                conn.setReadOnly(false);  // restore NOT readOnly before return to pool
            }
            conn.close();
        }
    }
@author Robert HG (254963746@qq.com) on 5/20/15.
lts-core/src/main/java/com/github/ltsopensource/store/jdbc/SqlTemplateImpl.java