从Weblogic控制的数据源在Oracle连接下执行缓慢的sql

Question

问题

返回大约500行的简单sql需要：

1. 在Toad中40毫秒（这会返回前500行）
2. 500-600 ms在Java中，从一个实例获得连接 oracle.jdbc.pool.OracleDataSource类。
3. 2100-2500 ms in Java，从数据中获取连接 通过JNDI
查找在Weblogic中配置的源代码

上述时间排除了获取连接实例。

问题：选项3的性能下降。为什么？如何使其更合理？

设置

1. Weblogic 10.3.5
2. Oracle 11g RDMBS

测试代码

    import java.sql.Connection;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.sql.Statement;
    import java.util.ArrayList;
    import java.util.GregorianCalendar;
    import java.util.Hashtable;
    import java.util.List;

    import javax.naming.Context;
    import javax.naming.InitialContext;
    import javax.naming.NamingException;
    import javax.sql.DataSource;

    import oracle.jdbc.OracleConnection;
    import oracle.jdbc.pool.OracleDataSource;

    import Facility;
    import BrowserSQL;

    public class JDBCTest {
        public static Connection conn;
        public static Connection getConnection(){
            String url= "localhost:1521:testdb";
            String usr="test";
            String pswd="test";
            Connection conn = null;
            try {
                OracleDataSource ods = new OracleDataSource();
                ods.setURL("jdbc:oracle:thin:@" + url);
                ods.setUser(usr);
                ods.setPassword(pswd); 
                conn = ods.getConnection();
            } catch (SQLException e) {
                e.printStackTrace();
            }

            return conn;
        }

        public static Connection getConnectionWeblogicJndi(){
            Connection conn = null;
            try {
                Hashtable ht = new Hashtable();
                ht.put(Context.INITIAL_CONTEXT_FACTORY, "weblogic.jndi.WLInitialContextFactory");
                ht.put(Context.PROVIDER_URL, "t3://localhost:7001");
                Context ctx = new InitialContext(ht);
                DataSource ods = (DataSource)ctx.lookup("jdbc/test");
                conn = ods.getConnection();
            } catch (SQLException e) {
                e.printStackTrace();
            } catch (NamingException e) {
                e.printStackTrace();
            }

            return conn;
        }

        //get the next val from given sequence.
        public static void runQuery(Connection conn, String sql){
            ResultSet rs=null;
            Statement stmt=null;
            try{
                stmt = conn.createStatement();
                rs = stmt.executeQuery(sql);
                while(rs.next()){}
            }catch(SQLException ex){
                ex.printStackTrace();
            }
            finally{
                close(rs,stmt,conn);
            }
        }

        public static void close(ResultSet rs, Statement ps, Connection conn){
            if (rs!=null) {
                try { rs.close(); } catch(SQLException ex) { ex.printStackTrace(); }
            }
            if (ps != null) {
                try { ps.close(); } catch (SQLException ex) { ex.printStackTrace(); }
            }
            if(conn !=null){
                try{ conn.close(); }catch(SQLException ex){ ex.printStackTrace(); }
            }
        }

        public static void main(String[]arg) throws SQLException {
            //Connection conn = JDBCTest.getConnectionWeblogicJndi();
            Connection conn = JDBCTest.getConnection();
            ((OracleConnection)conn).setDefaultRowPrefetch(1000);
            long a = GregorianCalendar.getInstance().getTimeInMillis();
            System.out.println("Stating testGetAllFacilityByQuery..."+a);
            runQuery(conn, BrowserSQL.getAllFacilities());
            long b = GregorianCalendar.getInstance().getTimeInMillis();
            System.out.println("End testGetAllFacilityByQuery..."+b + " -------- total time: "+(b-a)+" ms");
        }
    }