MVC模式下的數據展示:EasyUI的datagrid，mvceasyui

MVC模式下的數據展示:EasyUI的datagrid，mvceasyui

我的數據庫設計是一張老師表teacher,一張學生表student,一個教師對應多個學生,在學生一方建立外鍵;

還有一點想清楚,需要展示的數據是根據什麼來的,是成功登陸的用戶的id?還是直接展示所有的學生?

student表

教師表:

我是習慣性的從後寫到前,這裡展示的是登錄成功的老師下的學生信息

1 建立項目,建立好對應的包以及工具包

2建立好與數據庫對應的實體類 

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,因為使用的是easyUI,所以傳入參數多了起始頁碼start和頁面容量pageSize,這兩個參數都是從頁面的datagrid獲取的,是datagrid自帶的參數,方便後面的分頁

package com.zr.dao;
import java.util.List;
import com.zr.model.Student;
public interface StudentDao {
    /**
     * 
     * @param tid
     * @return 學生對象
     * 根據老師id返回學生對象
     */
    public  List<Student> getStudentBytid(int tid,int start,int pageSize);
    
    /**
     * 根據學生id刪除學生
     * @param s
     * @return
     */
    public  boolean  deleteStudentsBysid(String  s[]);
    /**
     * 根據學生id更新學生信息
     * @param student
     * @return
     */
    public  boolean  updateStudentBysid(int sid, String sname,String sage);
    /**
     * 根據當前老師id添加學生
     */
    public  boolean  addStudent(String sname,String sage,int tid);

/**
     * @param tid傳入老師ID
     * @return 返回學生總數
     */
    public  int  getScountStudentByTid(int tid);

}

4 StudentDaoImpl.java實現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{
    /**
     * 根據傳入的老師id獲取學生
     */
    public List<Student> getStudentBytid(int tid,int start,int pageSize) {
        //定義學生對象集合students接收數據庫返回
        List<Student>  students =  new ArrayList<Student>();
        //獲取數據庫連接
        Connection con=JDBCUtil.getConnection();
        //編寫SQL語句
        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);
            //返回一個結果集
            ResultSet rs=pst.executeQuery();
            while (rs.next()) {
                //學生對象接收結果集的結果
                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層:searchService.java以及實現層searchServiceImpl.java

package com.zr.service;
import java.util.List;
import com.zr.model.Student;
public interface searchService {
    /**
     * 查詢服務
     * @param tid 通過老師ID
     * @return 學生對象所有信息
     */
public List<Student> getStudents(int  tid,int start,int pageSize);

/**
 * 
 * @param tid傳入老師ID
 * @return 返回學生總數
 */
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 控制層com.zr.controller.SearchController.java

注:控制層涉及一個參數scount是當前老師下的學生總數

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 {
        //設置字符編碼
        req.setCharacterEncoding("utf8");
        resp.setCharacterEncoding("utf8");
        //實例化服務層,方便參數調用
        searchService s=new searchServiceImpl();
        //獲取datagrid的分頁參數page當前頁碼和頁面容量rows,保持參數名一直        
        int page=Integer.parseInt(req.getParameter("page"));
        int rows=Integer.parseInt(req.getParameter("rows"));
        //用學生集合接收返回的數據
        List<Student> students=new  ArrayList<Student>();
        //起始頁碼start=當前頁碼減1乘以頁面容量
        int start= (page-1)*rows;
        //獲取存放在session中的teacher對象,在登錄的時候返回老師對象並存入session對象
        Teacher teacher=(Teacher) req.getSession().getAttribute("teacher");
        //獲取老師ID
        int  tid=   teacher.getTid();

        int scount =s.getScountStudentByTid(tid);
        //根據老師id獲取學生對象 
        students= s.getStudents(tid, start, rows);
        //easy前台接收的是json對象JSONObject
        JSONObject jso=new JSONObject();
        //將數據返回給datagrid
        jso.put("total",scount);
        //rows後邊的參數代表需要在前台顯示的數據,格式為json的集合,再放入json的對象中
        jso.put("rows", JSONArray.fromObject(students));
        jso.put("page", start);
        resp.getWriter().write(jso.toString());
        
    }
    }

7 前台頁面編寫main.jsp

數據展示並不需要進行過多的配置,只需要配置好對應的列名以及請求參數,數據格式,本頁面前台的配置包含整個數據的增加,刪除,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(){
    //將增加框和修改框進行隱藏
    $('#updateStu').dialog('close');
    $('#addStu').dialog('close');
    //配置學生信息表格
    $('#students').datagrid({    
        url:'${pageContext.request.contextPath}/selectStus',    
        columns:[[    
            {field:'checked',checkbox:true,width:100},
            {field:'sid',title:'ID',width:100},    
            {field:'sname',title:'姓名',width:100},    
            {field:'sage',title:'年齡',width:100,align:'right'}    
        ]],
        pagination : true, //顯示分頁
        pagePosition:'bottom',//分頁顯示在底部
        toolbar: [{ iconCls: 'icon-edit',
            text:'添加',
            handler: function(){
                $('#addStu').dialog('open');//點擊添加按鈕顯示添加框
                
                
                }
        },'-',{
            iconCls: 'icon-delete',
            text:'刪除',
            handler: function(){
                
                var sids='';
                var ss=$("#students").datagrid('getSelections');//接收選中的對象結果集
               
                  if(ss.length==0){//對選中的大小判斷
                    $.messager.alert('這是一個提示信息！','請至少選擇一條數據進行刪除!');
                }else{
                 //對選中數據的id以逗號進行拼接,結果會多一個逗號,後台再進行處理:截取字符串
                $.messager.confirm('提示', '確認刪除？', function(r) {
                    $.each(ss,function(n,v){
                         sids=sids+v.sid+',' 
                });
                    $.ajax({
                        type:'post',
                        url:'${pageContext.request.contextPath}/deleteStus',
                        data:{'sids':sids},
                        dataType:"text",
                        success:function(data){
                            if(data=="1"){
                                $.messager.alert('提示','刪除成功！');
                               $("#students").datagrid('reload'); 
                               
                           }else{
                               $.messager.confirm('刪除失敗!',"刪除數據失敗!");
                           }
                        }
                    })
                });
            }
                }
        },'-',{
            iconCls: 'icon-update',
            text:'修改',
            handler: function(){
                var stus = $("#students").datagrid('getSelections');
                
                if (stus.length != 1) {
                    $.messager.confirm('提示', '請選擇一條數據', function(r){
            
                            $("#students").datagrid('unselectAll');
                        
                    })
                } else {
                    //顯示修改框
                    $('#updateStu').dialog('open');

                  //將選中的數據加載到修改面板上

                   var stu = stus[0];
                    $('#upStu').form('load',stu);
                    
          
                }
                
            
            }
        }]

    }); 
    
    /* 配置添加框 */
    $("#addStuf").form({
        type:'post',
        url:'${pageContext.request.contextPath}/AddStu',
        dataType:"text",
        success : function(data) {
            if(data=="1"){
                
                $('#addStu').dialog('close');
                $('#addStuf').form('clear');
                $.messager.alert('我的消息','添加商品信息成功','info',function(){
                    $('#students').datagrid('reload');
                });
            }else{
                $.messager.alert('我的消息','添加商品信息失敗，重新添加','info',function(){
                    $("#addStuf").form('clear');
                });
            }
        }
    });
    
    /* 配置修改框 */
    $("#upStu").form({
        type:'post',
        url:'${pageContext.request.contextPath}/updataStu',
        dataType:"text",
        success : function(data) {
        
            if(data=="1"){
                
               $("#students").datagrid('reload'); 
               $.messager.alert('提示!','修改成功');    
               $('#updateStu').dialog('close');
               
           }else{
               $.messager.alert('我的消息','修改學生信息失敗!','修改失敗!',function(){
                   $('#upStu').form('clear');
                });  
              
           }
        }
    });
    
    <!--配置搜索框,該功能尚未實現-->
    $('#searchStu').searchbox({
        searcher : function(value, name) {
            var sname = value;
            $('#goods').datagrid('reload', {
                searchname : sname,
            });
        }
    });

});

//配置修改學生信息表單提交
function updataForm() {
    $("#upStu").form('submit');
}

function addForm() {
    $("#addStuf").form('submit');
    
}
</script>
</head>
<body>
<input id="searchStu" class="easyui-searchbox"
        data-options="prompt:'輸入學生查詢信息',width:150">
    
    <table id="students"></table>
    
    <!-- 配置修改框面板 -->
    <div id="updateStu" class="easyui-dialog" title="更新學生信息信息"
         data-options="modal:true">
        
        <form id="upStu" method="post">
        //id默認隱藏,這樣就不允許修改
        <div >
                <span>id</span>
                <input class="easyui-textbox" name="sid" id="sid" >
            </div>
            <div >
                <span>學生姓名</span>
                <input class="easyui-textbox" name="sname" >
            </div>
            <div >
                <span>學生年齡</span>
                <input class="easyui-textbox" name="sage" >
            </div>
        </form>
        <div >
            <a href="javascript:void(0)" class="easyui-linkbutton"
                onclick="updataForm()"  id="tt">提交</a> 
        </div>
    </div>
    
    
    
        <!-- 配置增加框 -->
    <div id="addStu" class="easyui-dialog" title="添加學生信息信息"
         data-options="modal:true">
        
        <form id="addStuf" method="post">
            <!-- <div>-->
            <div >
                <span>學生姓名</span>
                <input class="easyui-textbox" name="sname" >
            </div>
            
            <div >
                <span>&nbsp;&nbsp;&nbsp;&nbsp;學生年齡</span>
                <input class="easyui-textbox" name="sage">
            </div>
        </form>
        
        <div >
            <a href="javascript:void(0)" class="easyui-linkbutton"
                onclick="addForm()"  id="tt">提交</a> 
        </div>
    </div>
</body>
</html>

最後配置請求文件

  <!-- 查詢當前下面的學生信息 -->
          <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>

最後數據展示:

總結:利用easyUI進行數據展示的時候,自帶的參數page,rows是需要獲取的,並以此來實現分頁功能;

後台返回到前台的時候,需要返回三個參數:

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

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

第三個需要返回的是數據總數total:jso.put("total",scount);