【求助】使用occi连接数据库时出错：ORA-12537:TNS:connection closed

我的想法很简单很简单。。。

只不过是：刚在新装的Centos下安装了oracle11g。在sqlplus下使用select table_name from user_tables，能够成功执行并返回结果，说明数据库已经正常运行了。
现在想要通过写一个occi连接oracle的小程序在本机测验一下是否能够正常操作oracle数据库。代码极其简单：

#include <iostream>

#include <occi.h>

#include <sstream>

#include <time.h>

using namespace std;

using namespace oracle::occi;



int main()

{

    Environment *env = Environment::createEnvironment(Environment::DEFAULT);    

    string name = "sys";

    string pass = "123";

    string srvName = "xxx.xxx.xxx.xxx:1521/ORCL";    //ip是本机的ip地址。

    cout << " run to 1 !!!!!!!!" << endl;

    Connection *conn = env->createConnection(name,pass,srvName);

    cout << " run to 2 !!!!!!!!" << endl;

    if(conn) cout << "con suc" << endl;

    Statement *stmt = NULL;

    string sql = "select table_name from user_tables where rownum<=5";

    stmt = conn->createStatement();

    stmt->setSQL(sql);

    ResultSet *rs = NULL;    

    rs = stmt->executeQuery();

    while(rs->next())

    {

        cout << "name: " << rs->getString(1) << endl;

    }

    

    return 0;    

}

编译通过后，先sqlplus>startup，后lsnrctl start。
运行程序，出现错误：ORA-12514: TNS:listener does not currently know of service requested in connect descriptor
出现此问题后，查询解决方法，在listener.ora文件中加入：
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(GLOBAL_DBNAME = ORCL.LOCAL)
(ORACLE_HOME = /opt/oracle/11g)
(SID_NAME = ORCL)
)
)
先关闭后重启数据库服务和监听。再次运行程序又出现错误：ORA-12537: TNS:connection closed

使用lsnrctl status查看监听状态显示如下：

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 21-FEB-2014 18:50:56



Copyright (c) 1991, 2009, Oracle.  All rights reserved.



Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))

STATUS of the LISTENER

------------------------

Alias                     LISTENER

Version                   TNSLSNR for Linux: Version 11.2.0.1.0 - Production

Start Date                21-FEB-2014 18:01:47

Uptime                    0 days 0 hr. 49 min. 9 sec

Trace Level               off

Security                  ON: Local OS Authentication

SNMP                      OFF

Listener Parameter File   /opt/oracle/11g/network/admin/listener.ora

Listener Log File         /opt/oracle/diag/tnslsnr/ma/listener/alert/log.xml

Listening Endpoints Summary...

  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))

  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=222.201.139.194)(PORT=1521))(PROTOCOL_STACK=(PRESENTATION=GIOP)(SESSION=RAW)))

Services Summary...

Service "ORCL.LOCAL" has 1 instance(s).

  Instance "ORCL", status UNKNOWN, has 1 handler(s) for this service...

The command completed successfully

状态是unknown是否不对啊，是不是应该是ready才对呢？
此问题，在网上查了好多资料还是不知道如何解决，网上有说是限制ip的问题，在我的配置里边没有限制。
我只是想使用occi编程操作数据库，数据库现在应该是正常运行了，可能是网络连接配置的问题，现在连接不上数据。

现在真的迷茫了，大家帮帮忙，这是怎么回事。