spring、ibatis控制oracle分页的问题

开发采用spring+ibatis，数据库用oracle，数据量有几千万以上，而且还要不断的增多，用了三层子查询实现分页控制

下面都只是举的例子

<sqlMap namespace="Y_wjlx">

	<resultMap class="com.ctgusec.model.Y_wjlx" id="y_wjlx">
		<result property="wjbh" column="wjbh" />
		<result property="wjmc" column="wjmc" />
	</resultMap>
	<select id="getAllY_wjlx" resultMap="y_wjlx">
		<![CDATA[			
		SELECT wjbh,wjmc FROM (SELECT row_.*, rownum rownum_ FROM (select wjbh,wjmc,rownum rn from y_wjlx) row_ WHERE rownum <= #end#) WHERE rownum_ > #start#
		]]>
	</select>

</sqlMap>

用了个模型基类存储分页参数，模型类可以继承此类

public class BaseModel {

	private Integer start = 0;

	private Integer end = 30;

	private Integer size = 30;

	private Integer currentPage;

	private Integer priviousPage;

	private Integer nextPage;

	public BaseModel() {
		
	}
	public BaseModel(Integer currentPage) {
		if (currentPage > 0) {
			this.currentPage = currentPage;
			this.priviousPage = currentPage - 1;
			this.nextPage = currentPage + 1;
			this.start = priviousPage * size;
			this.end = currentPage * size;
		}
	}

	//省略geter、serter方法
}

dao层：

public class SqlY_wjlxDao extends SqlMapClientDaoSupport implements IY_wjlxDao {

	public List getAllY_wjlx(Y_wjlx y_wjlx) {
		
		return this.getSqlMapClientTemplate().queryForList("getAllY_wjlx", y_wjlx);		
	}
}

控制层：spring控制类实现分页

public class Y_wjlxListAllController extends AbstractController {

	Integer currentPage ;
	
	//y_wjlx类继承BaseModel类
	Y_wjlx y_wjlx;

	@Override
	protected ModelAndView handleRequestInternal(HttpServletRequest request,
			HttpServletResponse response) throws Exception {
		String page = request.getParameter("page");
		if (page == null || page.equals("head")) {
			currentPage=1;
			y_wjlx = new Y_wjlx(currentPage);
			request.getSession().setAttribute("currentPage", currentPage);
		}
		if ("privious".equals(page)) {
			currentPage = (Integer) request.getSession().getAttribute("currentPage");
			if(currentPage>1) currentPage -= 1;
			y_wjlx = new Y_wjlx(currentPage);
			request.getSession().setAttribute("currentPage", currentPage);
		} else if ("next".equals(page)) {
			currentPage = (Integer) request.getSession().getAttribute("currentPage");
			currentPage += 1;
			y_wjlx = new Y_wjlx(currentPage);
			request.getSession().setAttribute("currentPage", currentPage);
		}
		List list = this.drv_Manager.getAllY_wjlx(y_wjlx);
		return new ModelAndView("y_wjlxList", "list", list);
	}

	private IDrv_Manager drv_Manager;

	public void setDrv_Manager(IDrv_Manager drv_Manager) {
		this.drv_Manager = drv_Manager;
	}
}

jsp页面分页调用

<button onclick="location.href  =  'y_wjlxList.shtml?page=head'">首&&页</button>    
&&
<button onclick="location.href  =  'y_wjlxList.shtml?page=privious'">上一页</button>    
&&
<button   onclick="location.href='y_wjlxList.shtml?page=next'">下一页</button>

实现了分页，而且前面的数据查询翻页效率很高，但是越到后面越慢（这个好象是没有办法的）

现在的问题是：
1、spring控制类太累赘，好象做了它不该做的事情，翻页控制有没有比较好的办法抽到服务层？
2、翻页也只有：首页、上页、下页；想把最后一页也弄出来，但是担心效率太低，首先要统计数据总数，还有就是三层子查询到了几千万数据后效率就慢了。
有没有比较好的解决办法？