DAO 层接口 package com.itheima.dao; import java.util.List; import com.itheima.domain.Account; public interface AccountDao { /** * 获取表的总记录数 * @return */ public int getCount(); /** * 分页查询 * @param startIndex * @param size * @return */ public List<Account> getAccountByPage(int startIndex,int size); }
DAO层实现
package com.itheima.dao.impl; import java.sql.SQLException; import java.util.List; import org.apache.commons.dbutils.QueryRunner; import org.apache.commons.dbutils.handlers.BeanListHandler; import org.apache.commons.dbutils.handlers.ScalarHandler; import com.itheima.dao.AccountDao; import com.itheima.domain.Account; import com.itheima.utils.C3P0Util; public class AccountDaoImpl implements AccountDao { private QueryRunner qr = new QueryRunner(C3P0Util.getDataSource()); public int getCount() {//获取总数 try { int count = ((Long)qr.query("select count(*) from account",new ScalarHandler())).intValue(); return count; } catch (SQLException e) { e.printStackTrace(); throw new RuntimeException(e); } } public List<Account> getAccountByPage(int startIndex, int size) {//获取当前页面的数据 try { return qr.query("select * from account limit ?,?",new BeanListHandler<Account>(Account.class),startIndex,size); } catch (SQLException e) { e.printStackTrace(); throw new RuntimeException(e); } } }
service 层接口
package com.itheima.service; import com.itheima.utils.PageBean; public interface AccountService { /** * 进行分页查询 * @param pb 引用数据类型，在方法体内做的修改，可以保留 */ public void findAccountByPage(PageBean pb); }
service层实现
package com.itheima.service.impl; import java.util.List; import com.itheima.dao.AccountDao; import com.itheima.dao.impl.AccountDaoImpl; import com.itheima.domain.Account; import com.itheima.service.AccountService; import com.itheima.utils.PageBean; public class AccountServiceImpl implements AccountService { private AccountDao dao = new AccountDaoImpl(); public void findAccountByPage(PageBean pb) { int count = dao.getCount();//总记录数 pb.setTotalRecordes(count);//设置总记录数 List<Account> list = dao.getAccountByPage(pb.getStartIndex(), pb.getPageSize());//查询出当前页的记录 pb.setRecordes(list);//设置当前页的记录 } }
pagebeans
package com.itheima.utils; import java.io.Serializable; import java.util.List; public class PageBean implements Serializable { private int pageNo=1;//当前页 private int pageSize=3;//每页显示的记录数 private int prep;//上一页 private int nextp;//下一页 private int totalPage;//总页数 private int totalRecordes;//总记录数 private List recordes;// 当前页的记录 private int startIndex;//当前页的第一条记录的索引 limit startIndex,size //为了加入滚动数字 private int beginPageno; private int endPageno; public int getBeginPageno() { //设置页码 1 2 3 4 5 6 7 8 9 (看到的数字) if(pageNo<=9){ beginPageno=1; endPageno = this.getTotalPage();//总记录数 }else{ //说明当前页已超出9 beginPageno=pageNo-4; endPageno = pageNo+4; if(beginPageno<=0) beginPageno=1; if(endPageno>getTotalPage()) endPageno=this.getTotalPage(); } return beginPageno; } public void setBeginPageno(int beginPageno) { this.beginPageno = beginPageno; } public int getEndPageno() { return endPageno; } public void setEndPageno(int endPageno) { this.endPageno = endPageno; } private String url; public int getPageNo() { return pageNo; } public void setPageNo(int pageNo) { this.pageNo = pageNo; } public int getPageSize() { return pageSize; } public void setPageSize(int pageSize) { this.pageSize = pageSize; } public int getPrep() { if(pageNo<=1){ prep=1; }else{ prep=pageNo-1; } return prep; } public void setPrep(int prep) { this.prep = prep; } public int getNextp() { if(pageNo>=this.getTotalPage()){ nextp=this.getTotalPage(); }else{ //没有超出边界 nextp=pageNo+1; } return nextp; } public void setNextp(int nextp) { this.nextp = nextp; } public int getTotalPage() { if(totalRecordes%pageSize==0){ totalPage = totalRecordes/pageSize; }else{ totalPage = totalRecordes/pageSize+1; } return totalPage; } public void setTotalPage(int totalPage) { this.totalPage = totalPage; } public int getTotalRecordes() { return totalRecordes; } public void setTotalRecordes(int totalRecordes) { this.totalRecordes = totalRecordes; } public List getRecordes() { return recordes; } public void setRecordes(List recordes) { this.recordes = recordes; } public int getStartIndex() { startIndex = (pageNo-1)*pageSize; return startIndex; } public void setStartIndex(int startIndex) { this.startIndex = startIndex; } public String getUrl() { return url; } public void setUrl(String url) { this.url = url; } }
sevlet
package com.itheima.web.servlet; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.itheima.service.AccountService; import com.itheima.service.impl.AccountServiceImpl; import com.itheima.utils.PageBean; public class ControllerServlet extends HttpServlet { private AccountService as = new AccountServiceImpl(); public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //1.乱码 response.setContentType("text/html;charset=UTF-8"); //2.生成一个分页组件对象 PageBean pb = new PageBean(); //3.设置一个新的当前页 （假设页面上传入进来当前页的参数名pageNo） String pageNo = request.getParameter("pageNo"); if(pageNo!=null && !"".equals(pageNo)){ pb.setPageNo(Integer.parseInt(pageNo));//设置当前页 } //4.调用业务方法，实现分页查询 as.findAccountByPage(pb); //4.1补充url的设置 pb.setUrl(request.getContextPath()+"/servlet/ControllerServlet"); //5.将分页组件放入request域中 request.setAttribute("page", pb); //6.转发到页面 request.getRequestDispatcher("/list.jsp").forward(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doGet(request, response); } }
jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title></title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <style type="text/css"> div{ text-align:center; } </style> </head> <body> <table border="1" width="600" align="center"> <tr> <td>ID</td> <td>Name</td> <td>Money</td> <td>操作</td> </tr> <c:forEach items="${requestScope.page.recordes }" var="account"> <tr> <td>${account.id }</td> <td>${account.name }</td> <td>${account.money }</td> <td><a href="">更新</a></td> </tr> </c:forEach> </table> <%@include file="/commons/page.jsp" %> </body> </html>
js p（提取）
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <div> 当前${page.pageNo } 页/共${page.totalPage } 页 <a href="${page.url }?pageNo=${page.prep}">上一页</a> <!-- 滚动数字 --> <c:forEach begin="${page.beginPageno }" end="${page.endPageno }" var="no"> <a href="${page.url }?pageNo=${no}">${no }</a> </c:forEach> <a href="${page.url }?pageNo=${page.nextp}">下一页</a> 选择<select onchange="changePage(this)"> <c:forEach begin="1" end="${page.totalPage }" var="i"> <option value="${i }" ${page.pageNo==i?"selected='selected'":"" }>${i }</option> </c:forEach> </select>页 <script> function changePage(objOpt){ window.location.href="${page.url}?pageNo="+objOpt.value; } </script> </div>