为什么要使用CachedRowSetImpl？

 1 package com.ifly.myhome.test;
 2 import java.sql.*;
 3 import com.sun.rowset.CachedRowSetImpl;
 4 public class test {
 5     private static Connection con;
 6     private static String user = "kh";
 7     private static String password = "kh";
 8     private static  String className = "com.mysql.jdbc.Driver";
 9     private static String url = "jdbc:mysql://localhost:3306/student";
10     public static void main(String[] args) {
11         try {
12             Class.forName(className);
13             con = DriverManager.getConnection(url, user, password);
14             String sql="select * from student";
15             PreparedStatement pstm=con.prepareStatement(sql);
16             pstm.execute();
17             ResultSet rs=pstm.getResultSet();
18             CachedRowSetImpl rowset=new CachedRowSetImpl();
19             rowset.populate(rs);
20             rs.close();
21             pstm.close();
22             con.close();
23             while (rowset.next()) {
24                 System.out.println("id:"+rowset.getString("id"));
25                  
26             }
27              
28         } catch (Exception e) {
29             // TODO Auto-generated catch block
30             e.printStackTrace();
31         }
32     }