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
$('#updateStu').dialog('close');
$('#addStu').dialog('close');
//配置学生信息表格
$('#students').datagrid({
url:'${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:'年龄',width:100,align:'right'}
]],
pagination : true, //显示分页
pagePosition:'bottom',//分页显示在底部
toolbar: [{ iconCls: 'icon-edit',
text:'添加',
handler: function(){
$('#addStu').dialog('open');//点击添加按钮显示添加框
}
},'-',{
iconCls: 'icon-delete',
text:'删除',
handler: function(){
var sids='';
var ss=$("#students").datagrid('getSelections');//接收选中的对象结果集
if(ss.length==0){//对选中的大小判断
$.messager.alert('这是一个提示信息！','请至少选择一条数据进行删除!');
}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('提示', '确认删除？', 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','删除成功！');
$("#students").datagrid('reload');
}else{
$.messager.confirm('删除失败!',"删除数据失败!");
}
}
})
});
}
}
},'-',{
iconCls: 'icon-update',
text:'修改',
handler: function(){
var stus = $("#students").datagrid('getSelections');
if (stus.length != 1) {
$.messager.confirm('提示', '请选择一条数据', function(r){
$("#students").datagrid('unselectAll');
})
} else {
//显示修改框
$('#updateStu').dialog('open');
//将选中的数据加载到修改面板上
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','添加商品信息失败，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','修改学生信息失败!','修改失败!',function(){
$('#upStu').form('clear');
});
}
}
});
<!--配置搜索框,该功能尚未实现-->
$('#searchStu').searchbox({
searcher : function(value, name) {
var sname = value;
$('#goods').datagrid('reload', {
searchname : sname,
});
}
});
});
//配置修改学生信息表单提交
function updataForm() {
$("#upStu").form('submit');
}
function addForm() {
$("#addStuf").form('submit');
}
</script>
</head>
<body>
<input id="searchStu" class="easyui-searchbox"
data-options="prompt:'输入学生查询信息',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);
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