一个分页

    这个分页采用的是oracle的后台分页，但是却没有将他分层。因为只是写给别人的一个小参考。而我也是扒的别人的代码，不过在自己机器上调试还是通过了的。之前一直知道分页，但是自己还真没有写过分页。只有毕业设计的时候写过，现在看看惨不忍睹，一开始就是一个select  *  从数据库里面全部取出来，然后放到一个List里面。而这个确实后台分页。因为是扒的别人的代码所以有点凌乱，不过对自己理解分页却还是不过。那个人呢的注释很详细。

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

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowCallbackHandler;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.servlet.ModelAndView;

import cn.ac.caf.ld.pojo.LinDiXianZhuang;

@Controller
public class Pagination {

	private Log log = LogFactory.getLog(Pagination.class);
	private 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;

	@Autowired
	private JdbcTemplate jdbcTemplate;

	public Pagination() {
	}

	/**
	 * 　　* 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, int currentPage, int numPerPage,
			JdbcTemplate jdbcTemplate) {
		// 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(" )  ");
		setJdbcTemplate(jdbcTemplate);
		// 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();
		// 构造oracle数据库的分页语句
		StringBuffer paginationSQL = new StringBuffer(" SELECT * FROM ( ");
		paginationSQL.append(" SELECT A.* , ROWNUM RN  FROM ( ");
		paginationSQL.append(sql);
		paginationSQL.append("　) A WHERE ROWNUM <= " + lastIndex);
		paginationSQL.append("  and qsdm!='00' and qydm!='00' ) WHERE　RN > "
				+ startIndex);
		log.info(totalSQL);
		log.info(paginationSQL);
		// 装入结果集
		 setResultList(getJdbcTemplate().queryForList(paginationSQL.toString()));
		final List<LinDiXianZhuang> ldMessage = new ArrayList<LinDiXianZhuang>();
		jdbcTemplate.query(paginationSQL.toString(), new RowCallbackHandler() {
			@Override
			public void processRow(ResultSet rs) throws SQLException {
				LinDiXianZhuang linDiXianZhuang = new LinDiXianZhuang();
				setAllProperty(rs, linDiXianZhuang);
				ldMessage.add(linDiXianZhuang);
			}
		});
		setResultList(ldMessage);
		log.info(getJdbcTemplate().queryForList(paginationSQL.toString()));
	}
	

	//这个是通过服务器访问测试
	@RequestMapping(value = "/page.do")
	public ModelAndView page(@RequestParam("currentPage") int currentPage,
			HttpServletRequest request, HttpServletResponse response) {
		String sql = "select * from t_sta_01_2010";
		Pagination pageInfo = new Pagination(sql.toString(), currentPage, 10,
				jdbcTemplate);
		log.info("总页数" + pageInfo.getTotalPages());
		log.info("总记录数:" + pageInfo.getTotalRows());

		pageInfo.getTotalPages();
		pageInfo.getResultList();
		pageInfo.getStartIndex();
		pageInfo.getLastIndex();
		ModelAndView mv = new ModelAndView();
		mv.addObject("result", pageInfo.getResultList());
		mv.addObject("totalRows",pageInfo.getTotalRows());
		mv.addObject("totalPage",pageInfo.getTotalPages());
		mv.addObject("startIndex", pageInfo.getStartIndex());
		mv.addObject("lastIndex", pageInfo.getLastIndex());
		mv.setViewName("page");
		return mv;
	}

	//这是用来测试，不需要跑tomcat。不过可以采用junit
	public static void main(String[] args) {
		ApplicationContext ctx = new ClassPathXmlApplicationContext(
				"applicationContext.xml");
		DataSource dataSource = (DataSource) ctx.getBean("dataSource");
		JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);
		String sql = "select * from t_sta_01_2010";
		Pagination pageInfo = new Pagination(sql.toString(), 2, 10,
				jdbcTemplate);
		pageInfo.getTotalPages();

	}

	// 计算起始行数
	public void setStartIndex() {
		this.startIndex = (currentPage - 1) * numPerPage;
	}

	// 计算总页数
	public void setTotalPages() {
		if (totalRows % numPerPage == 0) {
			this.totalPages = totalRows / numPerPage;
		} else {
			this.totalPages = (totalRows / numPerPage) + 1;
		}
	}

	public void setLastIndex() {
		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;
		}
	}

	public int getNumPerPage() {
		return numPerPage;
	}

	public void setNumPerPage(int numPerPage) {
		this.numPerPage = numPerPage;
	}

	public int getTotalRows() {
		return totalRows;
	}

	public void setTotalRows(int totalRows) {
		this.totalRows = totalRows;
	}

	public int getTotalPages() {
		return totalPages;
	}

	public void setTotalPages(int totalPages) {
		this.totalPages = totalPages;
	}

	public int getCurrentPage() {
		return currentPage;
	}

	public void setCurrentPage(int currentPage) {
		this.currentPage = currentPage;
	}

	public int getStartIndex() {
		return startIndex;
	}

	public void setStartIndex(int startIndex) {
		this.startIndex = startIndex;
	}

	public int getLastIndex() {
		return lastIndex;
	}

	public void setLastIndex(int lastIndex) {
		this.lastIndex = lastIndex;
	}

	public List getResultList() {
		return resultList;
	}

	public void setResultList(List resultList) {
		this.resultList = resultList;
	}

	public JdbcTemplate getJdbcTemplate() {
		return jdbcTemplate;
	}

	public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
		this.jdbcTemplate = jdbcTemplate;
	}

	/**
	 * 封装所有林地信息
	 * */
	public void setAllProperty(ResultSet rs, LinDiXianZhuang linDiXianZhuang)
			throws SQLException {
		//垃圾代码。就不贴出来了

}

 

可以通过http://localhost:8080/xxx/page.do?currentPage=xx来访问了。代码没有优化过，只是为了记忆