idle timeout and max wait time in j2ee db connection pool

There two parameters( idel timeout, max wait time) can be configure at Sun
Application Server console in j2ee.
However, seemingly no timeout is generated even i set both parameters to be
2 seconds.
Is there any place in my program where i can set sleep so that timeout can
be generated when
two parameters are set to 1 second.

Thanks in advance.

TW

Pool Settings
Idle Timeout:
    Maximum time that a connection can remain idle in the pool. (default is
300)
Max Wait Time:
    Amount of time caller waits before connection timeout is sent

private static javax.sql.DataSource dataSource_;
private SessionContext context;
private static String JNDI_NAME = "java:comp/env/jdbc/TestDB2";
private static javax.sql.DataSource dataSource_;
private static String SELECT_USER_DB = "SELECT * FROM IIMS2_USERS";
private Connection connection_;

try{
            javax.naming.Context c = new javax.naming.InitialContext();
            dataSource_ = (javax.sql.DataSource) c.lookup("jdbc/myoracle");

            Statement st = connection_.createStatement();
            ResultSet rs = st.executeQuery(SELECT_USER_DB);

            while(rs.next()){
                User us = new
User(rs.getString("id"),rs.getString("ACC_NAME"));
                vec.add( us );
            }
            try{
            Thread.sleep(5000);
            }catch( Exception e){

            }
            st.close();
            rs.close();
        }catch( SQLException e ){
            e.printStackTrace();
        }finally{
            if( connection_ != null ){
                try{
                   connection_.close();
                }catch(SQLException e ){
                   e.printStackTrace();
               }
            }
        }