运用EasyUI中datagrid读取数据库数据实现分页

com.hanqi.dao; import java.util.ArrayList; import java.util.List; import org.hibernate.Query; 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.han.entity.Student; public class StudentDAO { //定义变量 Configuration cfg = null ; ServiceRegistry sr = null ; SessionFactory sf = null ; Session se = null ; Transaction ts = null ; //构造方法 public StudentDAO() { //1获取配置文件 cfg = new Configuration().configure() ; //2注册配置 sr = new StandardServiceRegistryBuilder(). applySettings(cfg.getProperties()).build(); } //初始化方法 private void init() { //3获取SessionFactory sf = cfg.buildSessionFactory(sr) ; //4产生Session se =sf.openSession() ; //5启动事务 ts = se.beginTransaction() ; } //关闭释放资源 private void destroy() { ts.commit(); //提交事务 se.close() ;//关闭释放资源 sf.close();//关闭释放资源 } //获取分页数据集合 public List<Student> getPageList(int page, int rows) { List<Student> list = new ArrayList<>() ;//定义list变量并实例化 init() ;//初始化方法 list = se.createQuery("from Student") .setMaxResults(rows)//每页行数 .setFirstResult((page-1)*rows)//起始页码 .list() ; destroy() ;//关闭释放资源 return list ;//返回该集合 } //获取数据条数 public int getTotal() { int rtn = 0 ;//定义变量并赋值 init() ;//初始化方法 Query qu = se.createQuery("select count(1) from Student ") ;//获取Query对象 List<Object> list = qu.list() ;//定义list变量并实例化 if(list != null && list.size() > 0 )//判断获取的集合非空及长度 { rtn = Integer.parseInt(list.get(0).toString()) ;//给变量rtn赋值 } destroy();//关闭并释放资源 return rtn ;//返回变量值 } }

2service层

package com.hanqi.service;

import java.util.List;

import com.alibaba.fastjson.JSONArray;
import com.han.entity.Student;
import com.hanqi.dao.StudentDAO;

public class StudentService {
    
    //查询分页数据，并返回JSON
    public String getPageJSON(int page, int rows)
    {
        String rtn = "{‘total‘:0,‘rows‘:[ ]}" ;
        
        int total =  new StudentDAO().getTotal() ;
        
        if(total > 0)
        {
            List<Student> list =  new StudentDAO().getPageList(page, rows) ;
            
            //将List集合转为JSON集合
            String json_list = JSONArray.toJSONString(list) ;
            
            //转义字符返回复合类型的JSON字符串
            rtn =  "{\"total\":"+total+",\"rows\":"+json_list+"}" ;
        }
        
        return rtn ;
    }
}

3servlet

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");
        
        //接收请求
            //1每页行数
        String rows = request.getParameter("rows") ;
        
            //2页码
        String page = request.getParameter("page") ;
        
        //System.out.println("rows = "+ rows );
        //System.out.println("page = " + page );
        if(page != null && rows != null)
        {
            int rowss = Integer.parseInt(rows) ;
            
            int pagess = Integer.parseInt(page) ;
             
            String json_list = new StudentService().getPageJSON(pagess, rowss) ;
            //返回数据
            System.out.println(json_list);
            response.getWriter().write(json_list) ;
        }
        else
        {
            response.getWriter().write("{total: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);
    }

}

4html

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<!-- 1    jQuery的js包 -->
<script type="text/javascript" src="jquery-easyui-1.4.4/jquery.min.js"></script>

<!-- 2    css资源 -->
<link rel="stylesheet" type="text/css" href="jquery-easyui-1.4.4/themes/default/easyui.css">

<!-- 3    图标资源 -->
<link rel="stylesheet" type="text/css" href="jquery-easyui-1.4.4/themes/icon.css"> 

<!-- 4    EasyUI的js包 -->
<script type="text/javascript" src="jquery-easyui-1.4.4/jquery.easyui.min.js"></script>
 
<!-- 5    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(){
$(‘#dg‘).datagrid({    
    url:‘StudentServlet‘,    
    columns:[[    
        {field:‘sno‘,title:‘课程号‘,width:100},    
        {field:‘sname‘,title:‘姓名‘,width:100},    
        {field:‘ssex‘,title:‘性别‘,width:100,align:‘right‘},
        {field:‘sbirthday‘,title:‘生日‘,width:100,align:‘right‘},
        {field:‘sclass‘,title:‘班级‘,width:100,align:‘right‘} 
    ]],
    pagination:true,//分页
    fitColumns:true,//列自适应宽度
});  
})
</script>
<table id="dg"></table>  
</body>
</html>

 

 

运用EasyUI中datagrid读取数据库数据实现分页

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