连接泄露的问题

我用的是MyEclipse6.5、oc4j、jdk1.4
但是我运行界面时，会报这样的异常，它不影响界面操作，但是时间长了会影响操作速度，使界面加载很慢。
以下是报的异常：
OrionCMTConnection not closed, check your code!
Logical connection not closed, check your code!
(Use -Djdbc.connection.debug=true to find out where the leaked connection was created)

我的action 代码：
public class MerchantQueryAction extends TPBaseAction {

public ActionForward executeAction(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws TPActionException {
String forwardPage = null;
Connection conn = null;
try {
conn = DBUtil.getConnection();
forwardPage = execManager(conn, form, request);// 执行业务操作
return mapping.findForward(forwardPage);
} catch (Exception e) {
e.printStackTrace();
throw new TPActionException(e);
} finally {
forwardPage = null;
DBUtil.close(conn);
}
}

private String execManager(Connection conn, ActionForm form,HttpServletRequest request) throws Exception {
DynaValidatorForm dyForm = (DynaValidatorForm) form;
RowSetPage rsp = null;
MerchantModel merModel = null ;
int pageNum = 1;
// 取得页面的欲翻页页码
if (request.getParameter("pageNum") != null && !request.getParameter("pageNum").equals("")) {
pageNum = Integer.parseInt(request.getParameter("pageNum"));
}
merModel=formToModel(dyForm);
//调用manager终端信息共享池查询方法
rsp=MerchantDAOExt.queryMerchant(merModel, pageNum, IConstants.PAGE_SIZE, conn);
request.setAttribute("RowSetPage", rsp);
request.setAttribute("mchntId", dyForm.get("mchntId"));
request.setAttribute("mchntName", dyForm.get("mchntName"));
request.setAttribute("othermMchntName", dyForm.get("othermMchntName"));
request.setAttribute("mchntType", dyForm.get("mchntType"));
request.setAttribute("mchntDirType", dyForm.get("mchntDirType"));
return IConstants.SUCCESS_KEY;
}

private MerchantModel formToModel(DynaValidatorForm df){
MerchantModel merModel=new MerchantModel();
merModel.setMchntid(StringUtil.convertNullToString(df.get("mchntId"))) ;//商户编号
merModel.setMchntname(StringUtil.convertNullToString(df.get("mchntName"))) ;//商户名称
merModel.setOthermMchntName(StringUtil.convertNullToString(df.get("othermMchntName"))) ;//手动输入的商户名称
merModel.setMchnttype(StringUtil.convertNullToString(df.get("mchntType"))) ;//商户下载类型
merModel.setMchntdirtype(StringUtil.convertNullToString(df.get("mchntDirType"))) ;//商户直充类型
    return merModel;
}

}

连接数据库操作代码：
public static RowSetPage queryMerchant(MerchantModel merModel, int pageNum, int pageSize, Connection conn) throws Exception {
PagedStatement ps = null ;
StringBuffer sql = new StringBuffer() ;

sql.append("select m.mchntname ,                            ");
sql.append("m.mchntid ,                                     ");
sql.append("m.mchntContact ,                                ");
sql.append("m.mchntphone ,                                  ");
sql.append("m.MchntType , m.MchntdirType ,                  ");
sql.append("a.mchntArea                                     ");
sql.append("from  m_merchant m , m_area a                   ");
sql.append("  where a.mchntArea = m.mchntArea               ");
if (merModel.getMchntid()!= null && !"".equals(merModel.getMchntid().trim())) {
sql.append(" AND m.MchntID like '%").append(merModel.getMchntid()).append("%' ");
}
if (merModel.getMchntname()!= null && !"".equals(merModel.getMchntname().trim()) && !"0".equals(merModel.getMchntname().trim())) {
sql.append(" AND replace(m.mchntid,' ','') = '").append(merModel.getMchntname().trim()).append("' ");
}
if (merModel.getOthermMchntName()!= null && !"".equals(merModel.getOthermMchntName().trim()) && "0".equals(merModel.getMchntname().trim())) {
sql.append(" AND m.Mchntname like '%").append(merModel.getOthermMchntName()).append("%' ");
}
if (merModel.getMchnttype()!= null && !"".equals(merModel.getMchnttype().trim())) {
sql.append(" AND replace(m.mchntType,' ','') = '").append(merModel.getMchnttype().trim()).append("' ");
}
if (merModel.getMchntdirtype()!= null && !"".equals(merModel.getMchntdirtype().trim())) {
sql.append(" AND replace(m.MchntdirType,' ','') = '").append(merModel.getMchntdirtype().trim()).append("' ");
}

log.debug(sql.toString());
try {
ps = new PagedStatement(sql.toString(),pageNum,pageSize) ;
return ps.executeQuery(conn) ;
        }catch(SQLException e){
         log.error(" queryMerchant Error", e);
            throw e;
        }
        finally{
            sql = null;
            if (ps != null) {
                ps.close();
                ps = null;
            }
        }
} --------------------编程问答-------------------- 谁能告诉我这个-Djdbc.connection.debug=true怎么用啊
--------------------编程问答-------------------- 嗨，哥们你这个问题后来怎么解决的？ --------------------编程问答-------------------- 同求，我现在也遇到了这样的问题，但是不知道怎么解决！

补充：Java ,  Web 开发