关于ibatis进行物理游标分页

http://www.iteye.com/topic/136712

详细demo:参照http://www.kusoft.net

我的数据库是采用mssql2000 
采用分页必定数据量比较大: 
按照ibatis的自带的是缓存分页.如果一大的肯定内存吃不消. 但是可以采用queryForList,却得不到总记录数码相. 
要得到总记录数,因此我采用物理游标进行分页. 
功能:需要得到结果的记录数,显示每页几行 

(1)定义一个接口Pager: 

public interface Pager {
    //总共几行
    public int getRows();
    //存入一页的数据
    public List<Object> getList();

    public void setList(List<Object> list);

    public void setRows(int rows);
}

(2)Pager实现类PagerImpl 

public class PagerImpl implements Pager {

    private List<Object> list = null;
    private int rows = 0;

    public List<Object> getList() {
        return list;
    }
    public void setList(List<Object> list) {
        this.list = list;
    }

    public int getRows() {
        return rows;
    }
    public void setRows(int rows) {
        this.rows = rows;
    }

}

(3)扩展ibatis自带接口 SqlMapExecutor 

//skip 起启行,max每页几行
 Pager queryForPager(String id, Object parameterObject, int skip, int max) throws SQLException;

  Pager queryForPager(String id, Object parameterObject, int skip) throws SQLException;
  //根据条件查出所有结果
  Pager queryForPager(String id, Object parameterObject) throws SQLException;

(4)扩展ibatis接口 SqlMapExecutor的实现类有两个SqlMapClientImpl,SqlMapSessionImpl 

SqlMapClientImpl的扩展如下
public Pager queryForPager(String id, Object paramObject, int skip, int max)
            throws SQLException {
        if (max <= 0)
            return getLocalSqlMapSession().queryForPager(id, paramObject, skip);
        else
            return getLocalSqlMapSession().queryForPager(id, paramObject, skip,
                    max);
    }

    public Pager queryForPager(String id, Object parameterObject, int skip)
            throws SQLException {
        return getLocalSqlMapSession().queryForPager(id, parameterObject, skip,
                SqlExecutor.NO_MAXIMUM_RESULTS);
    }

    public Pager queryForPager(String id, Object parameterObject)
            throws SQLException {
        return getLocalSqlMapSession().queryForPager(id, parameterObject,
                SqlExecutor.NO_SKIPPED_RESULTS, SqlExecutor.NO_MAXIMUM_RESULTS);
    }

(5)最终修改SqlExecutor获取总记录数 
SqlExecutor:439行 

if (resultMap != null) {
                // Skip Results
                if (rs.getType() != ResultSet.TYPE_FORWARD_ONLY) {
                    rs.beforeFirst();
                    if (skipResults > 0) {
                        rs.absolute(skipResults);
                    }
                } else {
                    for (int i = 0; i < skipResults; i++) {
                        if (!rs.next()) {
                            return;
                        }
                    }
                }

                // Get Results
                int resultsFetched = 0;
                while ((maxResults == SqlExecutor.NO_MAXIMUM_RESULTS || resultsFetched < maxResults)
                        && rs.next()) {
                    Object[] columnValues = resultMap
                            .resolveSubMap(request, rs).getResults(request, rs);
                    callback.handleResultObject(request, columnValues, rs);
                    resultsFetched++;
                }
                if (rs.getType() != ResultSet.TYPE_FORWARD_ONLY) {
                    rs.last();
                    request.setRows(rs.getRow());
                } else {
                    int total = skipResults + resultsFetched;
                    while(rs.next()){
                        total++;
                    }
                    request.setRows(total);
                }

            }

这样就可以了 

(6)如何调用 
6.1创建一个方法 

public static Pager pager(GroupVO vo,int offset,int limit)throws SQLException{
      return sqlMapper.queryForPager("list",vo,offset);
  }

public static void main(String[] args){
      try {
        SimpleExample se = new SimpleExample();
        GroupVO vo = new GroupVO();
        Pager pager = se.pager(vo,0,10);
         //vo.setGroup_no("100");
          //vo.setGroup_name("fengjian");
          //vo.setGroup_desc("thanks");

        System.out.println("totalsize = "+pager.getRows());
        List list = pager.getList();
        if(list!=null)
            for(int i=0; i<list.size(); i++){
                GroupVO v = (GroupVO)list.get(i);
                System.out.println("group no = " + v.getGroup_no());
            }

    } catch (SQLException e) {
        e.printStackTrace();
    }
  }

有什么不同看法:msn:linuxfjy@hotmail.com, mail: kusoft@qq.com