MVC模式下的数据展示:EasyUI的datagrid

我的数据库设计是一张老师表teacher,一张学生表student,一个教师对应多个学生,在学生一方建立外键;

还有一点想清楚,需要展示的数据是根据什么来的,是成功登陆的用户的id?还是直接展示所有的学生?

student表

教师表:

我是习惯性的从后写到前,这里展示的是登录成功的老师下的学生信息

1 建立项目,建立好对应的包以及工具包

 

2建立好与数据库对应的实体类 

package com.zr.model;
public class Student {
        private int sid;
        private  String  sname;
        private  String sage;
        //自行get  set
        public Student() {
            super();
        }
        public Student(int sid, String sname, String sage) {
            super();
            this.sid = sid;
            this.sname = sname;
            this.sage = sage;
        }

}

package com.zr.model;

public class Teacher {
            private  int  tid;
            private  String tname;
            private  String tpsw;
            //自行get set
            public Teacher(String tname, String tpsw) {
                super();
                this.tname = tname;
                this.tpsw = tpsw;
            }
            public Teacher(int tid, String tname, String tpsw) {
                super();
                this.tid = tid;
                this.tname = tname;
                this.tpsw = tpsw;
            }
            public Teacher() {
                super();
            }
}

3 StudentDao.java,因为使用的是easyUI,所以传入参数多了起始页码start和页面容量pageSize,这两个参数都是从页面的datagrid获取的,是datagrid自带的参数,方便后面的分页

package com.zr.dao;
import java.util.List;
import com.zr.model.Student;
public interface StudentDao {
    /**
     *
     * @param tid
     * @return 学生对象
     * 根据老师id返回学生对象
     */
    public  List<Student> getStudentBytid(int tid,int start,int pageSize);

    /**
     * 根据学生id删除学生
     * @param s
     * @return
     */
    public  boolean  deleteStudentsBysid(String  s[]);
    /**
     * 根据学生id更新学生信息
     * @param student
     * @return
     */
    public  boolean  updateStudentBysid(int sid, String sname,String sage);
    /**
     * 根据当前老师id添加学生
     */
    public  boolean  addStudent(String sname,String sage,int tid);


/**
     * @param tid传入老师ID
     * @return 返回学生总数
     */
    public  int  getScountStudentByTid(int tid);


}

4 StudentDaoImpl.java实现studentDao.java

package com.zr.daoIm;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import JDBCUtil.JDBCUtil;
import com.zr.dao.StudentDao;
import com.zr.model.Student;
public class StudentDaoImpl  implements StudentDao{
    /**
     * 根据传入的老师id获取学生
     */
    public List<Student> getStudentBytid(int tid,int start,int pageSize) {
        //定义学生对象集合students接收数据库返回
        List<Student>  students =  new ArrayList<Student>();
        //获取数据库连接
        Connection con=JDBCUtil.getConnection();
        //编写SQL语句
        StringBuffer sql=new StringBuffer("select sid,sname,sage from student where tid=? limit ?,?");
        try {
            PreparedStatement pst=con.prepareStatement(sql.toString());
            pst.setInt(1, tid);
            pst.setInt(2, start);
            pst.setInt(3, pageSize);
            //返回一个结果集
            ResultSet rs=pst.executeQuery();
            while (rs.next()) {
                //学生对象接收结果集的结果
                Student s=new Student();
                s.setSid(rs.getInt("sid"));
                s.setSname(rs.getString("sname"));
                s.setSage(rs.getString("sage"));
                students.add(s);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return students;
    }

@Override
    public int getScountStudentByTid(int tid) {
        int scounts=0;

        StringBuffer sql=new StringBuffer("select count(sid) scount from student where tid=?");
        Connection con=JDBCUtil.getConnection();
        try {
            PreparedStatement pst=con.prepareStatement(sql.toString());
            pst.setInt(1, tid);
            ResultSet rs=pst.executeQuery();
            while(rs.next()){
                scounts=rs.getInt("scount");
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return scounts;
    }

}

5 service层:searchService.java以及实现层searchServiceImpl.java

package com.zr.service;
import java.util.List;
import com.zr.model.Student;
public interface searchService {
    /**
     * 查询服务
     * @param tid 通过老师ID
     * @return 学生对象所有信息
     */
public List<Student> getStudents(int  tid,int start,int pageSize);

/**
 *
 * @param tid传入老师ID
 * @return 返回学生总数
 */
public  int  getScountStudentByTid(int tid);

}

package com.zr.serviceIm;

import java.util.ArrayList;
import java.util.List;
import com.zr.dao.StudentDao;
import com.zr.dao.TeacherDao;
import com.zr.daoIm.StudentDaoImpl;
import com.zr.daoIm.TeacherDaoImpl;
import com.zr.model.Student;
import com.zr.service.searchService;
public class searchServiceImpl implements searchService{

    public List<Student> getStudents(int tid,int start,int pageSize) {

        List<Student> students=new ArrayList<Student>();
        StudentDao studentDaoImpl =new StudentDaoImpl();
        students=    studentDaoImpl.getStudentBytid(tid,start,pageSize);
        return students;
    }

@Override
    public int getScountStudentByTid(int tid) {
        TeacherDao teacherDao =new TeacherDaoImpl();

        return teacherDao.getScountStudentByTid(tid);
    }
}

6 控制层com.zr.controller.SearchController.java

注:控制层涉及一个参数scount是当前老师下的学生总数

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import com.zr.model.Student;
import com.zr.model.Teacher;
import com.zr.service.searchService;
import com.zr.serviceIm.searchServiceImpl;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
public class SearchController extends HttpServlet {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        //设置字符编码
        req.setCharacterEncoding("utf8");
        resp.setCharacterEncoding("utf8");
        //实例化服务层,方便参数调用
        searchService s=new searchServiceImpl();
        //获取datagrid的分页参数page当前页码和页面容量rows,保持参数名一直
        int page=Integer.parseInt(req.getParameter("page"));
        int rows=Integer.parseInt(req.getParameter("rows"));
        //用学生集合接收返回的数据
        List<Student> students=new  ArrayList<Student>();
        //起始页码start=当前页码减1乘以页面容量
        int start= (page-1)*rows;
        //获取存放在session中的teacher对象,在登录的时候返回老师对象并存入session对象
        Teacher teacher=(Teacher) req.getSession().getAttribute("teacher");
        //获取老师ID
        int  tid=   teacher.getTid();

        int scount =s.getScountStudentByTid(tid);
        //根据老师id获取学生对象
        students= s.getStudents(tid, start, rows);
        //easy前台接收的是json对象JSONObject
        JSONObject jso=new JSONObject();
        //将数据返回给datagrid
        jso.put("total",scount);
        //rows后边的参数代表需要在前台显示的数据,格式为json的集合,再放入json的对象中
        jso.put("rows", JSONArray.fromObject(students));
        jso.put("page", start);
        resp.getWriter().write(jso.toString());

    }
    }

7 前台页面编写main.jsp

数据展示并不需要进行过多的配置,只需要配置好对应的列名以及请求参数,数据格式,本页面前台的配置包含整个数据的增加,删除,修改

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<link href="${pageContext.request.contextPath}/themes/bootstrap/easyui.css" rel="stylesheet">
<link href="${pageContext.request.contextPath}/themes/icon.css" rel="stylesheet">
<script src="${pageContext.request.contextPath}/js/jquery.min.js"></script>
<script src="${pageContext.request.contextPath}/js/jquery.easyui.min.js"></script>
<script src="${pageContext.request.contextPath}/js/easyui-lang-zh_CN.js"></script>
<title>login</title>
<script type="text/javascript">
$(function(){
    //将增加框和修改框进行隐藏
    $(&#39;#updateStu&#39;).dialog(&#39;close&#39;);
    $(&#39;#addStu&#39;).dialog(&#39;close&#39;);
    //配置学生信息表格
    $(&#39;#students&#39;).datagrid({
        url:&#39;${pageContext.request.contextPath}/selectStus&#39;,
        columns:[[
            {field:&#39;checked&#39;,checkbox:true,width:100},
            {field:&#39;sid&#39;,title:&#39;ID&#39;,width:100},
            {field:&#39;sname&#39;,title:&#39;姓名&#39;,width:100},
            {field:&#39;sage&#39;,title:&#39;年龄&#39;,width:100,align:&#39;right&#39;}
        ]],
        pagination : true, //显示分页
        pagePosition:&#39;bottom&#39;,//分页显示在底部
        toolbar: [{ iconCls: &#39;icon-edit&#39;,
            text:&#39;添加&#39;,
            handler: function(){
                $(&#39;#addStu&#39;).dialog(&#39;open&#39;);//点击添加按钮显示添加框


                }
        },&#39;-&#39;,{
            iconCls: &#39;icon-delete&#39;,
            text:&#39;删除&#39;,
            handler: function(){

                var sids=&#39;&#39;;
                var ss=$("#students").datagrid(&#39;getSelections&#39;);//接收选中的对象结果集

                  if(ss.length==0){//对选中的大小判断
                    $.messager.alert(&#39;这是一个提示信息！&#39;,&#39;请至少选择一条数据进行删除!&#39;);
                }else{
                 //对选中数据的id以逗号进行拼接,结果会多一个逗号,后台再进行处理:截取字符串
                $.messager.confirm(&#39;提示&#39;, &#39;确认删除？&#39;, function(r) {
                    $.each(ss,function(n,v){
                         sids=sids+v.sid+&#39;,&#39;
                });
                    $.ajax({
                        type:&#39;post&#39;,
                        url:&#39;${pageContext.request.contextPath}/deleteStus&#39;,
                        data:{&#39;sids&#39;:sids},
                        dataType:"text",
                        success:function(data){
                            if(data=="1"){
                                $.messager.alert(&#39;提示&#39;,&#39;删除成功！&#39;);
                               $("#students").datagrid(&#39;reload&#39;);

                           }else{
                               $.messager.confirm(&#39;删除失败!&#39;,"删除数据失败!");
                           }
                        }
                    })
                });
            }
                }
        },&#39;-&#39;,{
            iconCls: &#39;icon-update&#39;,
            text:&#39;修改&#39;,
            handler: function(){
                var stus = $("#students").datagrid(&#39;getSelections&#39;);

                if (stus.length != 1) {
                    $.messager.confirm(&#39;提示&#39;, &#39;请选择一条数据&#39;, function(r){

                            $("#students").datagrid(&#39;unselectAll&#39;);

                    })
                } else {
                    //显示修改框
                    $(&#39;#updateStu&#39;).dialog(&#39;open&#39;);

                  //将选中的数据加载到修改面板上
                   var stu = stus[0];
                    $(&#39;#upStu&#39;).form(&#39;load&#39;,stu);


                }


            }
        }]

    });

    /* 配置添加框 */
    $("#addStuf").form({
        type:&#39;post&#39;,
        url:&#39;${pageContext.request.contextPath}/AddStu&#39;,
        dataType:"text",
        success : function(data) {
            if(data=="1"){

                $(&#39;#addStu&#39;).dialog(&#39;close&#39;);
                $(&#39;#addStuf&#39;).form(&#39;clear&#39;);
                $.messager.alert(&#39;我的消息&#39;,&#39;添加商品信息成功&#39;,&#39;info&#39;,function(){
                    $(&#39;#students&#39;).datagrid(&#39;reload&#39;);
                });
            }else{
                $.messager.alert(&#39;我的消息&#39;,&#39;添加商品信息失败，重新添加&#39;,&#39;info&#39;,function(){
                    $("#addStuf").form(&#39;clear&#39;);
                });
            }
        }
    });

    /* 配置修改框 */
    $("#upStu").form({
        type:&#39;post&#39;,
        url:&#39;${pageContext.request.contextPath}/updataStu&#39;,
        dataType:"text",
        success : function(data) {

            if(data=="1"){

               $("#students").datagrid(&#39;reload&#39;);
               $.messager.alert(&#39;提示!&#39;,&#39;修改成功&#39;);
               $(&#39;#updateStu&#39;).dialog(&#39;close&#39;);

           }else{
               $.messager.alert(&#39;我的消息&#39;,&#39;修改学生信息失败!&#39;,&#39;修改失败!&#39;,function(){
                   $(&#39;#upStu&#39;).form(&#39;clear&#39;);
                });

           }
        }
    });

    <!--配置搜索框,该功能尚未实现-->
    $(&#39;#searchStu&#39;).searchbox({
        searcher : function(value, name) {
            var sname = value;
            $(&#39;#goods&#39;).datagrid(&#39;reload&#39;, {
                searchname : sname,
            });
        }
    });

});

//配置修改学生信息表单提交
function updataForm() {
    $("#upStu").form(&#39;submit&#39;);
}

function addForm() {
    $("#addStuf").form(&#39;submit&#39;);

}
</script>
</head>
<body>
<input id="searchStu" class="easyui-searchbox"
        data-options="prompt:&#39;输入学生查询信息&#39;,width:150">

    <table id="students"></table>

    <!-- 配置修改框面板 -->
    <div id="updateStu" class="easyui-dialog" title="更新学生信息信息"
        style="width: 400px; height: 450px;" data-options="modal:true">

        <form id="upStu" method="post">
        //id默认隐藏,这样就不允许修改
        <div style="margin-bottom: 20px;">
                <span>id</span>
                <input class="easyui-textbox" name="sid" id="sid" style="width: 200px;display: none;">
            </div>
            <div style="margin-bottom: 20px">
                <span>学生姓名</span>
                <input class="easyui-textbox" name="sname" style="width: 200px">
            </div>
            <div style="margin-bottom: 20px">
                <span>学生年龄</span>
                <input class="easyui-textbox" name="sage" style="width: 200px">
            </div>
        </form>
        <div style="text-align: center; padding: 5px 0;">
            <a href="javascript:void(0)" class="easyui-linkbutton"
                onclick="updataForm()" style="width: 80px" id="tt">提交</a>
        </div>
    </div>



        <!-- 配置增加框 -->
    <div id="addStu" class="easyui-dialog" title="添加学生信息信息"
        style="width: 400px; height: 450px;" data-options="modal:true">

        <form id="addStuf" method="post">
            <!-- <div style="margin-bottom: 20px;display: none;">
                <span>学生ID</span>
                <input class="easyui-textbox" name="sid" style="width: 200px;">
            </div> -->
            <div style="margin-bottom: 20px">
                <span>学生姓名</span>
                <input class="easyui-textbox" name="sname" style="width: 200px">
            </div>

            <div style="margin-bottom: 20px">
                <span>    学生年龄</span>
                <input class="easyui-textbox" name="sage">
            </div>
        </form>

        <div style="text-align: center; padding: 5px 0;">
            <a href="javascript:void(0)" class="easyui-linkbutton"
                onclick="addForm()" style="width: 80px" id="tt">提交</a>
        </div>
    </div>
</body>
</html>

最后配置请求文件

<!-- 查询当前下面的学生信息 -->
          <servlet>
              <servlet-name>selectStus</servlet-name>
              <servlet-class>com.zr.controller.SearchController</servlet-class>
          </servlet>
          <servlet-mapping>
                  <servlet-name>selectStus</servlet-name>
                  <url-pattern>/selectStus</url-pattern>
          </servlet-mapping>

最后数据展示:

总结:利用easyUI进行数据展示的时候,自带的参数page,rows是需要获取的,并以此来实现分页功能;

后台返回到前台的时候,需要返回三个参数:

page: int page=Integer.parseInt(req.getParameter("page"));   int start= (page-1)*rows;   jso.put("page", start);

rows是需要展示的数据json集合 jso.put("rows", JSONArray.fromObject(students));

第三个需要返回的是数据总数total:jso.put("total",scount);