Oracle分页例子

package test;

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

import cc.yiyao.dbConn.JdbcUtil;

public class Test2 {

//Oracle分页 //Oracle分页 //Oracle分页

//分页调用例子
public static void main(String[] args) {
List list = new ArrayList();
int totalPage = splitPage(list,3,3);
System.out.println("totalPage="+totalPage);
for(int i=0; i<list.size();i++){
ChannelBean bean = (ChannelBean)list.get(i);
System.out.println("channelId="+bean.getChannelID()+", channel name="+bean.getChannelName());
}
}

//返回总共的页数,list为输出参数(即将list装满后返回,在程序中可以直接使用)
public static int splitPage(List list,int pageNo,int pageSize){
/*取2-4条数据例子:
* String sql = "select * from (select ROWNUM r,t1.* from (select * from coUser order by coUserId desc) t1 where rownum<=4) t2 where t2.r>=2 and t2.r<=4";
*
*/
if(pageNo<1){
pageNo = 1;
}
String sql1 = "select count(*) from channel";
Connection conn = JdbcUtil.getConnection();
Statement stmt = null;
ResultSet rs = null;
int count = 0;
try {
stmt = conn.createStatement();
rs = stmt.executeQuery(sql1);
if(rs.next()){
count = rs.getInt(1);
}
} catch (SQLException e) {
// TODO 自动生成 catch 块
e.printStackTrace();
}finally{
try {
if(rs != null){
rs.close();
rs = null;
}
if(stmt != null){
stmt.close();
stmt = null;
}
} catch (SQLException e) {
// TODO 自动生成 catch 块
e.printStackTrace();
}
}
int totalPage = (count%pageSize==0)? count/pageSize:count/pageSize+1; //数据库的总页数

if(pageNo > totalPage){
pageNo = totalPage;
}

// 判断开开始位置
int startPos = (pageNo-1)*pageSize + 1;

//判断结束位置
int endPos = pageNo*pageSize;
if(endPos > count){ //大于总记录数
endPos = count;
}
String sql2 = "select * from "+
"(select rownum r,t1.* from "+
" (select * from channel order by channelID desc) t1 "+
" where rownum<= "+ endPos+") t2 "+ //4= pageNo*pageSize
" where t2.r>="+startPos+" and t2.r<="+endPos; //

Statement stmt2 = null;
ResultSet rs2 = null;

try {
stmt2 = conn.createStatement();
rs2 = stmt2.executeQuery(sql2);
while(rs2.next()){
//将对象插入到list中

ChannelBean bean = new ChannelBean();
bean.setChannelID(rs2.getInt("channelID")); //取出包含r(rownum)了,所以要指定字段名
bean.setChannelCode(rs2.getString("ChannelCode"));
bean.setChannelName(rs2.getString("ChannelName"));
bean.setParentIDCode(rs2.getString("ParentIDCode"));
bean.setChannelInfo(rs2.getString("ChannelInfo"));
bean.setCreateDate(rs2.getString("CreateDate"));

list.add(bean);
}
} catch (SQLException e) {
// TODO 自动生成 catch 块
e.printStackTrace();
}finally{
try {
if(rs2 != null){
rs2.close();
rs2 = null;
}
if(stmt2 != null){
stmt2.close();
stmt2 = null;
}
if(conn != null){
conn.close();
conn = null;
}
} catch (SQLException e) {
// TODO 自动生成 catch 块
e.printStackTrace();
}
}

return totalPage;
}
}