如果你的查询有10000条记录,或者更多,速度肯定慢了,当然你可以通过resultset中的游标控制查询的起始和结束。我这里用的是Oracle数据库,使用伪列ROWNUM来实现分页。我的分页代码如下:
原文地址package com.deity.ranking.util;import java.util.List; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.jdbc.core.support.JdbcDaoSupport; /** * 分页函数 * * @author allenpan */public class Pagination extends JdbcDaoSupport{ public static final int NUMBERS_PER_PAGE = 10; //一页显示的记录数 private int numPerPage; //记录总数 private int totalRows; //总页数 private int totalPages; //当前页码 private int currentPage; //起始行数 private int startIndex; //结束行数 private int lastIndex; //结果集存放List private List resultList; //JdbcTemplate jTemplate private JdbcTemplate jTemplate; /** * 每页显示10条记录的构造函数,使用该函数必须先给Pagination设置currentPage,jTemplate初值 * @param sql oracle语句 */ public Pagination(String sql){ if(jTemplate == null){ throw new IllegalArgumentException("com.deity.ranking.util.Pagination.jTemplate is null,please initial it first. "); }else if(sql.equals("")){ throw new IllegalArgumentException("com.deity.ranking.util.Pagination.sql is empty,please initial it first. "); } new Pagination(sql,currentPage,NUMBERS_PER_PAGE,jTemplate); } /**分页构造函数 * @param sql 根据传入的sql语句得到一些基本分页信息 * @param currentPage 当前页 * @param numPerPage 每页记录数 * @param jTemplate JdbcTemplate实例 */ public Pagination(String sql,int currentPage,int numPerPage,JdbcTemplate jTemplate){ if(jTemplate == null){ throw new IllegalArgumentException("com.deity.ranking.util.Pagination.jTemplate is null,please initial it first. "); }else if(sql == null || sql.equals("")){ throw new IllegalArgumentException("com.deity.ranking.util.Pagination.sql is empty,please initial it first. "); } //设置每页显示记录数 setNumPerPage(numPerPage); //设置要显示的页数 setCurrentPage(currentPage); //计算总记录数 StringBuffer totalSQL = new StringBuffer(" SELECT count(*) FROM ( "); totalSQL.append(sql); totalSQL.append(" ) totalTable "); //给JdbcTemplate赋值 setJdbcTemplate(jTemplate); //总记录数 setTotalRows(getJdbcTemplate().queryForInt(totalSQL.toString())); //计算总页数 setTotalPages(); //计算起始行数 setStartIndex(); //计算结束行数 setLastIndex(); System.out.println("lastIndex="+lastIndex);////////////////// //构造oracle数据库的分页语句 StringBuffer paginationSQL = new StringBuffer(" SELECT * FROM ( "); paginationSQL.append(" SELECT temp.* ,ROWNUM num FROM ( "); paginationSQL.append(sql); paginationSQL.append(" ) temp where ROWNUM <= " + lastIndex); paginationSQL.append(" ) WHERE num > " + startIndex); //装入结果集 setResultList(getJdbcTemplate().queryForList(paginationSQL.toString())); } /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub } public int getCurrentPage() { return currentPage; } public void setCurrentPage(int currentPage) { this.currentPage = currentPage; } public int getNumPerPage() { return numPerPage; } public void setNumPerPage(int numPerPage) { this.numPerPage = numPerPage; } public List getResultList() { return resultList; } public void setResultList(List resultList) { this.resultList = resultList; } public int getTotalPages() { return totalPages; } //计算总页数 public void setTotalPages() { if(totalRows % numPerPage == 0){ this.totalPages = totalRows / numPerPage; }else{ this.totalPages = (totalRows / numPerPage) + 1; } } public int getTotalRows() { return totalRows; } public void setTotalRows(int totalRows) { this.totalRows = totalRows; } public int getStartIndex() { return startIndex; } public void setStartIndex() { this.startIndex = (currentPage - 1) * numPerPage; } public int getLastIndex() { return lastIndex; } public JdbcTemplate getJTemplate() { return jTemplate; } public void setJTemplate(JdbcTemplate template) { jTemplate = template; } //计算结束时候的索引 public void setLastIndex() { System.out.println("totalRows="+totalRows);/////////// System.out.println("numPerPage="+numPerPage);/////////// if( totalRows < numPerPage){ this.lastIndex = totalRows; }else if((totalRows % numPerPage == 0) || (totalRows % numPerPage != 0 && currentPage < totalPages)){ this.lastIndex = currentPage * numPerPage; }else if(totalRows % numPerPage != 0 && currentPage == totalPages){//最后一页 this.lastIndex = totalRows ; } }}在我的业务逻辑代码中: /** * find season ranking list from DC * @param areaId 选手区域id * @param rankDate 赛季 * @param category 类别 * @param characterName 角色名 * @return List */ public List findSeasonRankingList(Long areaId, int rankYear,int rankMonth, Long categoryId,String characterName) { //SQL语句 StringBuffer sql = new StringBuffer(" SELECT C.USERID userid,D.POSNAME posname,C.GAMEID gameid,C.AMOUNT amount,C.RANK rank FROM "); //表 sql.append(" (SELECT B.USERID USERID,"); sql.append(" B.POSID POSID,"); sql.append(" A.DISTRICT_CODE DISTRICTCODE,"); sql.append(" A.GAMEID GAMEID,"); sql.append(" AMOUNT AMOUNT,"); sql.append(" RANK RANK "); sql.append(" FROM TB_FS_RANK A "); sql.append(" LEFT JOIN TB_CHARACTER_INFO B "); sql.append(" ON A.DISTRICT_CODE = B.DISTRICT_CODE "); sql.append(" AND A.GAMEID = B.GAMEID "); //附加条件 if(areaId != null && areaId.intValue() != 0){ sql.append(" and A.DISTRICT_CODE = " + areaId.intValue()); } if( rankYear > 1970 && rankMonth > 0){ //hql.append(" and sas.id.dt >= to_date('" + rankYear + "-" + rankMonth + "-01 00:00:00'," + "YYYY-MM-DD HH24:MI:SS"); //hql.append(" and sas.id.dt <= to_date('" + rankYear + "-" + rankMonth + "-" + TimeTool.findMaxDateInMonth(rankYear,rankMonth) + " 23:59:59'," + "YYYY-MM-DD HH24:MI:SS"); sql.append(" and A.DT = fn_time_convert(to_date('" + rankYear + "-" + rankMonth + "'," + "'YYYY-MM')) "); } if(categoryId != null && categoryId.intValue() != 0){ sql.append(" and A.CID = " + categoryId.intValue()); } if(characterName != null && !characterName.trim().equals("")){ sql.append(" and A.GAMEID = '" + characterName.trim()+"' "); } sql.append(" ORDER BY RANK ASC) C "); sql.append(" LEFT JOIN TB_FS_POSITION D "); sql.append(" ON C.POSID = D.POSID "); sql.append(" ORDER BY C.RANK "); System.out.println("hql="+sql.toString());//////////////// //使用自己的分页程序控制结果集 Pagination pageInfo = new Pagination(sql.toString(),1,10,getJdbcTemplate()); return pageInfo.getResultList(); //return getJdbcTemplate().queryForList(sql.toString()); }