1.jsp代码
<script>
function select() {
var val = $("#inputcount").val();
window.location.href = "${pageContext.request.contextPath}/querypage?everyCount="+val;
}
</script>
<%--页面实现代码--%>
<body>
<div class="container">
<div class="row">
<span style="margin-left: 20px"> 每页显示</span>
<input type="text" style="height:30px;width:30px;border-radius: 8px" class="text-left text-info"
id="inputcount" value="10"> <span>条</span>
<button class="btn btn-success" οnclick="select()">查询</button>
<h3 style="text-align: center">我的所有项目</h3>
</div>
<table border="1" class="table table-bordered table-hover table-responsive text-center">
<tr class="success text-center">
<th></th>
<th>编号</th>
<th>项目名称</th>
<th>项目ID</th>
<th>项目类型</th>
<th>创建时间</th>
<th>项目路径</th>
<th colspan="2">操作</th>
</tr>
<c:forEach var="h" items="${pageBean.list}" varStatus="vs">
<tr>
<td><input type="checkbox"></td>
<td>${vs.count}</td>
<td>${h.pName}</td>
<td>${h.id}</td>
<td>${h.pType}</td>
<td>${h.date}</td>
<td>${h.pPath}</td>
<td>
<a class="btn btn-default btn-sm" href="#">修改</a>
<a class="btn btn-default btn-sm">删除</a>
</td>
</tr>
</c:forEach>
<tr>
<td colspan="8" align="center">
<ul class="pagination success">
<%--此处判断当前页是否是第一页，如果是第一页，上一页按钮不能用--%>
<c:if test="${pageBean.currentPage==1}">
<li class="disabled">
<a href="#" aria-label="Previous"><span aria-hidden="true">«</span>
</a>
</li>
</c:if>
<c:if test="${pageBean.currentPage!=1}">
<li class="disabled">
<a href="${pageContext.request.contextPath}/querypage?currentPage=${pageBean.currentPage-1}&everyCount=${pageBean.everypagecount}"
aria-label="Previous"><span aria-hidden="true">«</span>
</a>
</li>
</c:if>
<%--此处生成页号--%>
<c:forEach var="i" begin="1" end="${pageBean.countPage}" step="1">
<%--当前活动页面深色显示不能点击--%>
<c:if test="${pageBean.currentPage==i}">
<li class="active"><a
href="${pageContext.request.contextPath}/querypage?currentPage=${i}&everyCount=${pageBean.everypagecount}">${i}</a></li>
</c:if>
<c:if test="${pageBean.currentPage!=i}">
<li><a href="${pageContext.request.contextPath}/querypage?currentPage=${i}&everyCount=${pageBean.everypagecount}">${i}</a></li>
</c:if>
</c:forEach>
<%--此处判断是否为最后一页，如果是最后一页，下一页按钮不能用--%>
<c:if test="${pageBean.currentPage==pageBean.countPage}">
<li><a class="disabled" href="#" aria-label="Next"><span aria-hidden="true">»</span></a>
</li>
</c:if>
<c:if test="${pageBean.currentPage!=pageBean.countPage}">
<li><a class="disabled"
href="${pageContext.request.contextPath}/querypage?currentPage=${pageBean.currentPage+1}&everyCount=${pageBean.everypagecount}"
aria-label="Next"><span aria-hidden="true">»</span></a></li>
</c:if>
</ul>
</td>
</tr>
</table>
</div>
</body>
Dao层代码
/**
* 查询当前页面的数据
* @param currentPage 当前页
* @param a 每页记录数
* @return 当前页数据
*/
public List<Project> queryCurrentPageData(int currentPage, int a) {
String sql = "select * from project limit ?,? ";
int begin = (currentPage - 1) * a;//当前页开始数据位置
List<Project> currentProject = jdbcTemplate.query(sql, new BeanPropertyRowMapper<>(Project.class),begin,a);
return currentProject;
}
service层实现代码
/**
* 获取当前页的数据
*
* @param currentPage 当前页
* @param currentCountPage 当前页要显示的记录数
* @return
*/
public PageBean queryPageProject(String currentPage, String currentCountPage) {
int cp = Integer.parseInt(currentPage); //当前页
int ccp = Integer.parseInt(currentCountPage); //每页数据数
List<Project> currentPageList = projectOperationDao.queryCurrentPageData(cp, ccp); //当前页面用户数据
//将项目数据封装到PageBean
PageBean pageBean = new PageBean();
pageBean.setList(currentPageList); //当前页数据
pageBean.setCurrentPage(cp); //当前页
//查询数据库记录总条数
int pagecount = projectOperationDao.pagecount();
int ceil = (int) Math.ceil(pagecount/ ccp);
pageBean.setCountPage(ceil); //总页数
pageBean.setEverypagecount(ccp);
return pageBean;
}
4.web层实现代码（servlet的实现）
@WebServlet(name = "querypage", urlPatterns = "/querypage")
public class PageQueryServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
//获取每页显示的条数，如果未指定每页显示数目，则默认显示十条
String everyCount = request.getParameter("everyCount");
if (everyCount==null||"".equals(everyCount)){
everyCount="10";
}
//获取当前页
String currentPage = request.getParameter("currentPage");
if (currentPage==null||"".equals(currentPage)){
currentPage="1";
}
//调用查询方法查询每页数据
ProjectOperationService projectOperationService = new ProjectOperationService();
PageBean pageBean = projectOperationService.queryPageProject(currentPage, everyCount);
request.setAttribute("pageBean",pageBean);
request.getRequestDispatcher("/page/testpage/pagelist.jsp").forward(request,response);
}
}
5.JavaBean
package com.sps.entity;
import java.util.List;
public class PageBean {
private List<Project> list; //每页的项目数据
private int currentPage; //当前页
private int countPage; //总页数
private int everypagecount; //每页显示的记录数
public PageBean() {
}
public PageBean(List<Project> list, int currentPage, int countPage, int everypagecount) {
this.list = list;
this.currentPage = currentPage;
this.countPage = countPage;
this.everypagecount = everypagecount;
}
public int getEverypagecount() {
return everypagecount;
}
public void setEverypagecount(int everypagecount) {
this.everypagecount = everypagecount;
}
public List<Project> getList() {
return list;
}
public void setList(List<Project> list) {
this.list = list;
}
public int getCurrentPage() {
return currentPage;
}
public void setCurrentPage(int currentPage) {
this.currentPage = currentPage;
}
public int getCountPage() {
return countPage;
}
public void setCountPage(int countPage) {
this.countPage = countPage;
}
@Override
public String toString() {
return "PageBean{" +
"list=" + list +
", currentPage=" + currentPage +
", countPage=" + countPage +
", everypagecount=" + everypagecount +
'}';
}
}
6.util工具类和配置文件（此Demo用的是c3p0连接池和mysql数据库，可根据个人情况修改配置文件，此处包括util工具类和配置文件）
/**
* 目的:
* 1. 保证DataSource只有一个
* 2. 提供连接(DataSource获得)
* 3. 释放资源
*/
public class C3P0Utils {
//创建C3P0数据源(连接池)
private static DataSource dataSource = new ComboPooledDataSource();
/**
* 提供数据源
* @return
*/
public static DataSource getDataSource(){
return dataSource;
}
/**
* 从dataSource(连接池)获得连接对象
*
* @return
* @throws Exception
*/
public static Connection getConnection() throws Exception {
Connection connection = dataSource.getConnection();
return connection;
}
/**
* 释放资源
*
* @param resultSet
* @param statement
* @param connection
*/
public static void release(ResultSet resultSet, Statement statement, Connection connection) {
if (resultSet != null) {
try {
resultSet.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (statement != null) {
try {
statement.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (connection != null) {
try {
connection.close();//看Connection来自哪里, 如果Connection是从连接池里面获得的, close()方法其实是归还; 如果Connection是创建的, 就是销毁
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
---------------------------------以下是配置文件----------------------------------------
<c3p0-config>
<!--配置方式一：使用默认配置（default-config）读取连接池对象-->
<default-config>
<!--连接参数，必须要写的-->
<property name="driverClass"> com.mysql.jdbc.Driver</property>
<property name="jdbcUrl">jdbc:mysql://localhost:3306/mysystem </property>
<property name="user">root</property>
<property name="password">339869</property>
<!-- 连接池参数 -->
<property name="initialPoolSize">7</property>
<!--初始连接数：刚创建好连接池的时候准备的连接数量-->
<property name="maxPoolSize">10</property>
<!--最大连接数：连接池中最多可以放多少个连接-->
<property name="cheakoutTimeout">1000</property>
<!--最大等待时间：连接池中没有连接时最长等待时间-->
<property name="maxIdleTime">2000</property>
<!--最大空闲回收时间：连接池中的空闲连接多久没有使用就会回收-->
</default-config>
</c3p0-config>
7.实现效果图
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