JavaWeb---数据分页
Posted 夏小弥
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数据分页
这个东西就像是百度最下端的那个东西一样的功能的，如下：
功能说明：
1、在不使用上方搜索功能时，能够查看到所有的数据
2、下面的分页功能将数据分成了许多页，下方的分页我规定只让他显示十页(总共不止十页，后面的要所在页面移动才能够显示出其他的页面，就像百度的分页功能一样的)，每一页只显示十行数据
3、上面的查询功能也是借用了数据库的模糊查询功能实现的
当然了，这个小项目还需要使用到三个jar包：c3p0-0.9.1.2.jar、commons-dbutils-1.4.jar、mysql-connector-java-5.1.5-bin.jar
下面是代码：
配置文件：c3p0-config.xml
<c3p0-config>
<!-- 默认配置，如果没有指定则使用这个配置 -->
<default-config>
<property name="driverClass">com.mysql.jdbc.Driver</property>
<property name="jdbcUrl">
<![CDATA[jdbc:mysql://127.0.0.1:3306/mydata?useUnicode=true&characterEncoding=UTF-8]]>
</property>
<property name="user">root</property>
<property name="password"></property>
<!-- 初始化池大小 -->
<property name="initialPoolSize">2</property>
<!-- 最大空闲时间 -->
<property name="maxIdleTime">30</property>
<!-- 最多有多少个连接 -->
<property name="maxPoolSize">10</property>
<!-- 最少几个连接 -->
<property name="minPoolSize">2</property>
<!-- 每次最多可以执行多少个批处理语句 -->
<property name="maxStatements">50</property>
</default-config>
<!-- 命名的配置 -->
<named-config name="hncu">
<property name="driverClass">com.mysql.jdbc.Driver</property>
<property name="jdbcUrl">jdbc:mysql://127.0.0.1:3306/mydb</property>
<property name="user">root</property>
<property name="password"></property>
<property name="acquireIncrement">5</property><!-- 如果池中数据连接不够时一次增长多少个 -->
<property name="initialPoolSize">100</property>
<property name="minPoolSize">50</property>
<property name="maxPoolSize">1000</property>
<property name="maxStatements">0</property>
<property name="maxStatementsPerConnection">5</property> <!-- he's important, but there's only one of him -->
</named-config>
</c3p0-config>
<%@ 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>PagesDivided</title>
</head>
<body>
<a href="<c:url value='PageServlet2'/>">数据分页的分页</a>
</body>
</html>show2.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>showDividedPage</title>
<link rel="stylesheet" href="<c:url value='/css/table.css'/>"/>
<script type="text/javascript">
function change(obj)
window.location.href="<c:url value='/PageServlet2?page='/>"+obj.value;
</script>
</head>
<body>
<h3>数据查询</h3>
<form action='<c:url value="/PageServlet2"/>' method="post">
ID:<input type="text" name="id" value="$stud.id"/>
Name:<input type="text" name="name" value="$stud.name"/>
<input type="submit" value="模糊查询"/>
</form>
<hr/>
<h3 align="center">当前页面内容</h3>
<table>
<tr><th>学号</th><th>姓名</th></tr>
<c:forEach items="$result.datas" var="map">
<tr>
<td>$map.id</td>
<td>$map.name</td>
</tr>
</c:forEach>
</table>
<br/><br/>
<c:if test="$1!=result.currentPage">
<a href="<c:url value='/PageServlet2?page=$result.currentPage-1'/>">上一页</a>
</c:if>
<c:forEach begin="$showStart" end="$showEnd" var="idx">
<c:if test="$idx==result.currentPage">
$idx
</c:if>
<c:if test="$idx!=result.currentPage">
<span id="unselectedPage">
<a href="<c:url value='/PageServlet2?page=$idx'/>">$idx</a>
</span>
</c:if>
</c:forEach>
<c:if test="$result.pageCount!=result.currentPage">
<a href="<c:url value='/PageServlet2?page=$result.currentPage+1'/>">下一页</a>
</c:if>
<select οnchange="change(this)">
<c:forEach begin="1" end="$result.pageCount" var="idx">
<option <c:if test="$idx==result.currentPage">selected</c:if> value="$idx">
第$idx页
</option>
</c:forEach>
</select>
</body>
</html>table.css
table
clear:left;
border: 1px solid blue;
width:500px;
border-collapse: collapse;
margin: auto;
td
border: 1px solid blue;
text-align: center;
th
border: 1px solid blue;
body
text-align: center;
a
text-decoration: none;
#unselectedPage
border: 1px solid blue;
width:500px;
margin: auto;
公共类C3p0Pool.java
package cn.hncu.pubs;
import java.sql.Connection;
import java.sql.SQLException;
import javax.sql.DataSource;
import com.mchange.v2.c3p0.ComboPooledDataSource;
//我们的这个包装，只是为了把c3p0池做成让每个线程(客户端)获得的是同一个连接，方便做b/s框架下的事务
public class C3p0Pool
private static DataSource pool;
private static ThreadLocal<Connection> t=new ThreadLocal<Connection>();
static
pool=new ComboPooledDataSource();
public static DataSource getDataSource()
return pool;
public static Connection getConnection() throws SQLException
Connection con=t.get();
if (con==null)
con=pool.getConnection();
t.set(con);
return con;
DAO层
接口：IPageDAO2.java
package cn.hncu.page2.dao;
import java.util.Map;
import cn.hncu.page2.domain.Stud;
public interface IPageDAO2
public Map<String, Object> query(Integer pageNo, Stud stud) throws Exception;
package cn.hncu.page2.dao;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.MapListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;
import cn.hncu.page2.domain.Stud;
import cn.hncu.pubs.C3p0Pool;
public class PageJdbc2 implements IPageDAO2
private final int pageSize=10;
@Override
public Map<String, Object> query(Integer pageNo, Stud stud) throws Exception
Map<String, Object> result=new HashMap<String, Object>();
//总行数
String sql="select count(1) from dbutilsstud where 1=1 ";//查总行数
String sql2="select * from dbutilsstud where 1=1 ";//查内容
if (stud.getId()!=null&&stud.getId().trim().length()!=0)
sql+="and id like '%"+stud.getId()+"%'";
sql2+="and id like '%"+stud.getId()+"%'";
if (stud.getName()!=null&&stud.getName().trim().length()!=0)
sql+="and name like '%"+stud.getName()+"%'";
sql2+="and name like '%"+stud.getName()+"%'";
QueryRunner run=new QueryRunner(C3p0Pool.getDataSource());
int rows=Integer.parseInt(""+run.query(sql, new ScalarHandler()));
//总页数
int pageCount=rows/pageSize + (rows%pageSize==0 ? 0:1);
result.put("pageCount", pageCount);
//分页面内容
int startNo=(pageNo-1)*pageSize;
sql2=sql2+" limit "+startNo+", "+pageSize;
List<Map<String, Object>> datas=run.query(sql2, new MapListHandler());
result.put("datas", datas);
return result;
service层
接口：IPageService2.java
package cn.hncu.page2.service;
import java.util.Map;
import cn.hncu.page2.domain.Stud;
public interface IPageService2
public Map<String, Object> query(Integer pageNo, Stud stud) throws Exception;
package cn.hncu.page2.service;
import java.util.Map;
import cn.hncu.page2.dao.IPageDAO2;
import cn.hncu.page2.dao.PageJdbc2;
import cn.hncu.page2.domain.Stud;
public class PageServiceImpl2 implements IPageService2
//注入dao
IPageDAO2 dao=new PageJdbc2();
@Override
public Map<String, Object> query(Integer pageNo, Stud stud) throws Exception
return dao.query(pageNo, stud);
servlet ：PageServlet2.java
package cn.hncu.page2.servlet;
import java.io.IOException;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import cn.hncu.page2.domain.Stud;
import cn.hncu.page2.service.IPageService2;
import cn.hncu.page2.service.PageServiceImpl2;
public class PageServlet2 extends HttpServlet
//注入service
IPageService2 service=new PageServiceImpl2();
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
doPost(request, response);
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
String pageNo=request.getParameter("page");
if (pageNo==null||pageNo.trim().length()==0)
pageNo="1";
Stud stud=null;
if (request.getMethod().equalsIgnoreCase("GET"))
stud=(Stud) request.getSession().getAttribute("stud");
if (stud==null)
stud=new Stud();
else
stud=new Stud();
String id=request.getParameter("id");
String name=request.getParameter("name");
stud.setId(id);
stud.setName(name);
request.getSession().setAttribute("stud", stud);
try
Integer iPageNo=Integer.parseInt(pageNo);
Map<String, Object> result=service.query(iPageNo,stud);
//给结果集补一个数据: currentPage
result.put("currentPage", iPageNo);
//把结果集放入容器中
request.setAttribute("result", result);
int showSize=10;
int showStart=0;
int showEnd=0;
int pageCount=Integer.parseInt(""+result.get("pageCount"));
if (pageCount<showSize)
showStart=1;
showEnd=pageCount;
else
if (iPageNo<=(showSize/2+(showSize%2==0?0:1)))
showStart=1;
showEnd=showSize;
else
showStart=iPageNo-showSize/2;
showEnd=showStart+showSize-1;
if (showEnd>pageCount)
showEnd=pageCount;
showStart=showEnd-showSize+1;
request.setAttribute("showStart", showStart);
request.setAttribute("showEnd", showEnd);
//转到结果页面
request.getRequestDispatcher("/jsps/show2.jsp").forward(request, response);
catch (NumberFormatException e)
throw new RuntimeException("当前页格式转换错误", e);
catch (Exception e)
e.printStackTrace();
值对象层：Stud.java
package cn.hncu.page2.domain;
public class Stud
private String id;
private String name;
public Stud()
public String getId()
return id;
public void setId(String id)
this.id = id;
public String getName()
return name;
public void setName(String name)
this.name = name;
@Override
public int hashCode()
final int prime = 31;
int result = 1;
result = prime * result + ((id == null) ? 0 : id.hashCode());
return result;
@Override
public boolean equals(Object obj)
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Stud other = (Stud) obj;
if (id == null)
if (other.id != null)
return false;
else if (!id.equals(other.id))
return false;
return true;
这个小项目我是放在了page2这个包里面的，page1是这个项目的另一个版本，就没贴上来了；另外下面的show.jsp也是给另一个用的，这个项目使用的是show2.jsp
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