Java树结构如何优化以提高效率

Question

public GbiPrivilege getPrivilegeTree(UserInfo user) {
String sql = sqlMap("privilege.getall");
if (StringUtils.isBlank(sql)) {
throw new SqlNotFoundException("privilege.getall");
}
Map map = jdbcTemplate.queryForMap(sql, "0", "root");
GbiPrivilege pri = obtainSubGbiPrivilege(map);
String sqlall = sqlMap("privilege.getallpri");
if (StringUtils.isBlank(sqlall)) {
throw new SqlNotFoundException("privilege.getallpri");
}
List list = jdbcTemplate.queryForList(sqlall);
for (int i = 0; i < list.size(); i++) {
Map mapall = (Map) list.get(i);
GbiPrivilege gbi = obtainSubGbiPrivilege(mapall);
if (pri.getId().equals(gbi.getParentId())) {
pri.addSubPrivilege(gbi);
pri.setLeaf(false);
findChildren(list, gbi);
}
}
return pri;
}

private void findChildren(List list, GbiPrivilege superpri) {
    try {
        for (int i = 0; i < list.size(); i++) {             
            Map map = (Map) list.get(i);
            GbiPrivilege subpri = obtainSubGbiPrivilege(map);
            if (subpri.getParentId().equals(superpri.getId())) {
                superpri.addSubPrivilege(subpri);
                superpri.setLeaf(false);
                findChildren(list, subpri);
            }
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
} 

请教一下，这些代码还可以如何继续优化，提高效率