正文
easyui-datagrid连接数据库实现分页查询数据
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一、利用MVC思想建立底层数据库：
package com.hanqi.dao;import java.util.ArrayList;
import java.util.List;import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;import com.hanqi.entity.Student;public class StudentDAO { ServiceRegistry sr=null;
Configuration cfg=null;
SessionFactory sf=null;
Session se=null;
Transaction tr=null; public StudentDAO()
{
cfg=new Configuration().configure(); sr=new StandardServiceRegistryBuilder()
.applySettings(cfg.getProperties()).build(); }
//初始化
private void init()
{ sf=cfg.buildSessionFactory(sr);
se=sf.openSession();
tr=se.beginTransaction();
}
//提交和释放资源
private void destory()
{
tr.commit();
se.close();
sf.close();
}
//获取分页的数据集合
public List<Student> getPageList(int page,int rows)
{
List<Student> rtn=new ArrayList<Student>();
init();
int num=(page-)*rows;
rtn=se.createQuery("from Student").setFirstResult(num).setMaxResults(rows).list();
destory();
return rtn;
} //获取数据条数
public int getTotal()
{
int rtn=;
init();
List<Object>lo=se.createQuery("select count(1) from Student").list();
if(lo!=null&&lo.size()>)
{
rtn=Integer.parseInt(lo.get().toString());
} destory();
return rtn;
}}
二、建立service层
package com.hanqi.service;import java.util.List;import com.alibaba.fastjson.JSONArray;
import com.hanqi.dao.StudentDAO;
import com.hanqi.entity.Student;public class StudentService { //查询分页数据 //返回JSON
public String getPageJSON(int page,int rows)
{
String rtn="{'title':0,'rows':[]}"; int total=new StudentDAO().getTotal();
if(total>)
{
List<Student>ls= new StudentDAO().getPageList(page, rows); String ls_json=JSONArray.toJSONString(ls);
//利用转义字符转成JSON格式的语句
rtn="{\"total\":"+total+",\"rows\":"+ls_json+"}"; } return rtn;
}}
三、建立servlet：
package com.hanqi.web;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.hanqi.service.StudentService;/**
* Servlet implementation class StudentServlet
*/
public class StudentServlet extends HttpServlet {
private static final long serialVersionUID = 1L; /**
* @see HttpServlet#HttpServlet()
*/
public StudentServlet() {
super();
// TODO Auto-generated constructor stub
} /**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8");
response.setCharacterEncoding("UTF-8");
response.setContentType("text/html"); String spage=request.getParameter("page");
String srows=request.getParameter("rows"); if(spage!=null&& srows!=null)
{
int page=Integer.parseInt(spage);
int rows=Integer.parseInt(srows); String json =new StudentService().getPageJSON(page, rows); response.getWriter().print(json);
}
else
{
response.getWriter().print( "{'title':0,'rows':[]}");
}
} /**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}}
4、写出显示界面
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<!-- 、JQuery的js包 -->
<script type="text/javascript" src="jquery-easyui-1.4.4/jquery.min.js"></script>
<!-- css资源 -->
<link rel="stylesheet" type="text/css" href="jquery-easyui-1.4.4/themes/default/easyui.css">
<!-- 、图标资源 -->
<link rel="stylesheet" type="text/css" href="jquery-easyui-1.4.4/themes/icon.css">
<!-- 、easyui的js包 -->
<script type="text/javascript" src="jquery-easyui-1.4.4/jquery.easyui.min.js"></script><!-- 、本地语言 -->
<script type="text/javascript" src="jquery-easyui-1.4.4/locale/easyui-lang-zh_CN.js"></script>
</head>
<body>
<script type="text/javascript">
$(function(){
//创建data_grid
$("#st").datagrid({ url:'StudentServlet', //数据来源
//冻结列 //列的定义
columns:[[
{field:'sno',title:'学生编号',width:},
{field:'sname',title:'学生姓名',width:},
{field:'ssex',title:'性别',width:,align:'right'},
{field:'sbirthday',title:'生日',width:,align:'center',hidden:true},
{field:'sclass',title:'班级',width:,align:'right',sortable:true}
]], fitColumns:true,//列自适应宽度，不能和冻结列同时设置为true
striped:true,//斑马线效果
idField:'sno',//主键列
rownumbers:true,//显示行号
singleSelect:false,//是否单选
pagination:true,//显示分页栏
pageList:[,,,],//每页行数选择列表
pageSize:,//出事每页行数
remoteSort:false,//是否服务器端排序，设成false，才能客户端排序
sortName:'sclass'//设置排序列 });
})</script>
学生表
<br><br>
<table id="st"></table></body>
</html>
效果图：
