java中iterator的用法是否正确!

  jsp+javaBean:
数据库操作类:
 
package com.batian.common ;import java.sql.* ;public class DataBaseConnection
{
 
private final String DBDRIVER = "oracle.jdbc.driver.OracleDriver" ;
 
private final String DBURL = "jdbc:oracle:thin:@localhost:1521:INFORDB" ;
 
private final String DBUSER = "EIPS" ;
 
private final String DBPASSWORD = "manager" ;
 
private Connection conn = null ;  
public DataBaseConnection()
{
try
{
 
Class.forName(DBDRIVER) ; 
 
conn = DriverManager.getConnection(DBURL,DBUSER,DBPASSWORD) ;
}
catch (Exception e)
{
System.out.println(e) ;
}
}  
public Connection getConnection()
{
 
return this.conn ;
} 
public void close()
{
try
{
this.conn.close() ;
}
catch (Exception e)
{
}
}

// public static void main(String [] args){
// System.out.println(new DataBaseConnection().getConnection());
// }
};
DAO操作类:package com.batian.daoimpl;import java.sql.*;
import java.util.*;import com.batian.common.DataBaseConnection;
import com.batian.dao.InnvoationDAO;
import com.batian.vo.*;public class InnvoateDAOImpl implements InnvoationDAO { public List QueryList() {

List list = new ArrayList();
InnovationVO ivo = new InnovationVO();
DataBaseConnection dbc = null;
dbc = new DataBaseConnection();
PreparedStatement psmt = null;
ResultSet rs = null;
String sql = "select * from hrmt_innovation where rownum<=10";
//String sql = "select ID,INNOVATION_ID,INNOVATION_DAT,INNOVATION_ITEM,ORG_ID,INNOVATION_DATA from hrmt_innovation ";

try {
psmt = dbc.getConnection().prepareStatement(sql);
rs = psmt.executeQuery();
while(rs.next()){
ivo.setID(rs.getInt(1));
ivo.setINNOVATION_ID(rs.getString(2));
ivo.setINNOVATION_DAT(rs.getDate(3));
ivo.setINNOVATION_ITEM(rs.getString(4));
ivo.setORG_ID(rs.getString(5));
ivo.setINNOVATION_DATA(rs.getString(6));
list.add(ivo);
System.out.println("java's size():"+list.size());
}
rs.close();
psmt.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
dbc.close();
}
return list;
}}在JSP中显示:JSP源代码:[code=jsp]<%@ page contentType="text/html;charset=gb2312"%>
<%@ page import="java.sql.*,com.batian.daoimpl.*,java.util.*,com.batian.vo.*"%>
<html>
<head>
<title>分页显示</title>
</head>
<body>
<center>
<h1>Innvoation 信息列表</h1>
<hr>
<br>
<table border="1">
<tr>
         <th>ID</th>
         <th>INNO_ID</th>
         <th>INNO_DAT</th>
         <th>INNO_ITEM</th>
         <th>ORG_ID</th>
         <th>INNO_DATA</th>
    </tr>
<%
        List list = new InnvoateDAOImpl().QueryList();
        Iterator iter = list.iterator();
        System.out.println("size大小:"+list.size());
int i = 0 ;
while(iter.hasNext())
{
i++ ;
InnovationVO ivo = (InnovationVO)iter.next();
int id = ivo.getID() ;
String innovate_ID = ivo.getINNOVATION_ID() ;
java.sql.Date innovate_Date = ivo.getINNOVATION_DAT() ;
String innovate_Item = ivo.getINNOVATION_ITEM() ;
String org_ID = ivo.getORG_ID() ;
String innovate_Data = ivo.getINNOVATION_DATA() ;
%>
   <tr>
         <td><%=id %></td>
         <td><%=innovate_ID %></td>
         <td><%=innovate_Date%></td>
         <td><%=innovate_Item %></td>
         <td><%=org_ID %></td>
         <td><%=innovate_Data %></td>
       </tr>
<%
}
System.out.println("记录数为:"+i);
if(i==0)
{
%>
<tr>
<td colspan="6">没有任何数据！！</td>
</tr>
<%
}
%>
</table> 
</center>
</body>
</html>[/code]

解决方案 »

  1.   

    有什么问题。List可以用Iterator接口的
      

  2.   

    InnovationVO ivo = new InnovationVO(); //这行改成如下
    InnovationVO ivo = null;
    .....
                while(rs.next()){
                    ivo = new InnovationVO(); //加上这一行
                    ivo.setID(rs.getInt(1));
                    ivo.setINNOVATION_ID(rs.getString(2));
                    ivo.setINNOVATION_DAT(rs.getDate(3));
                    ivo.setINNOVATION_ITEM(rs.getString(4));
                    ivo.setORG_ID(rs.getString(5));
                    ivo.setINNOVATION_DATA(rs.getString(6));
                    list.add(ivo);
                    System.out.println("java's size():"+list.size());
                }