Ajax实现动态及时刷新表格数据

大家好，我是雄雄，今天分享的技术很简单，即ajax结合jdbc动态实现及时刷新表单数据。

前言：相信大家在网上冲浪的时候，肯定会发现这样的场景，在实现某个查询功能时，下方表格中会显示需要展示的结果，当查询条件换掉之后，数据表格中显示的信息也会及时更新，今天，我们就来实现一下这样的功能。

效果图如下所示：

​编辑

数据库：mysql

开发编辑器：myeclipse

浏览器：chrome

采用java三层架构分层开发，首先我们先来看看数据库的表结构：

Emp表：

​编辑

Dept表：

​编辑

接下来就是按照表结构写实体类，代码如下：

Emp实体类：

package org.entity;

public class Emp {
  
  private int eid;
  private String ename;
  private String epass;
  private int edid;
  private Dept dept;
  
  
  public Dept getDept() {
    return dept;
  }
  public void setDept(Dept dept) {
    this.dept = dept;
  }
  public int getEid() {
    return eid;
  }
  public void setEid(int eid) {
    this.eid = eid;
  }
  public String getEname() {
    return ename;
  }
  public void setEname(String ename) {
    this.ename = ename;
  }
  public String getEpass() {
    return epass;
  }
  public void setEpass(String epass) {
    this.epass = epass;
  }
  public int getEdid() {
    return edid;
  }
  public void setEdid(int edid) {
    this.edid = edid;
  }
  
  public Emp( String ename, String epass, int edid) {
    super();
    this.ename = ename;
    this.epass = epass;
    this.edid = edid;
  }
  
  public Emp(){
    
  }
  
  

}

Dept实体类：

package org.entity;

public class Emp {
  
  private int eid;
  private String ename;
  private String epass;
  private int edid;
  private Dept dept;
  
  
  public Dept getDept() {
    return dept;
  }
  public void setDept(Dept dept) {
    this.dept = dept;
  }
  public int getEid() {
    return eid;
  }
  public void setEid(int eid) {
    this.eid = eid;
  }
  public String getEname() {
    return ename;
  }
  public void setEname(String ename) {
    this.ename = ename;
  }
  public String getEpass() {
    return epass;
  }
  public void setEpass(String epass) {
    this.epass = epass;
  }
  public int getEdid() {
    return edid;
  }
  public void setEdid(int edid) {
    this.edid = edid;
  }
  
  public Emp( String ename, String epass, int edid) {
    super();
    this.ename = ename;
    this.epass = epass;
    this.edid = edid;
  }
  
  public Emp(){
    
  }
  
  

}

连接数据库所需的BaseDao：

package org.entity;

public class Emp {
  
  private int eid;
  private String ename;
  private String epass;
  private int edid;
  private Dept dept;
  
  
  public Dept getDept() {
    return dept;
  }
  public void setDept(Dept dept) {
    this.dept = dept;
  }
  public int getEid() {
    return eid;
  }
  public void setEid(int eid) {
    this.eid = eid;
  }
  public String getEname() {
    return ename;
  }
  public void setEname(String ename) {
    this.ename = ename;
  }
  public String getEpass() {
    return epass;
  }
  public void setEpass(String epass) {
    this.epass = epass;
  }
  public int getEdid() {
    return edid;
  }
  public void setEdid(int edid) {
    this.edid = edid;
  }
  
  public Emp( String ename, String epass, int edid) {
    super();
    this.ename = ename;
    this.epass = epass;
    this.edid = edid;
  }
  
  public Emp(){
    
  }
  
  

}

接着，就是Dao层接口，IEmpDao：

package org.entity;

public class Emp {
  
  private int eid;
  private String ename;
  private String epass;
  private int edid;
  private Dept dept;
  
  
  public Dept getDept() {
    return dept;
  }
  public void setDept(Dept dept) {
    this.dept = dept;
  }
  public int getEid() {
    return eid;
  }
  public void setEid(int eid) {
    this.eid = eid;
  }
  public String getEname() {
    return ename;
  }
  public void setEname(String ename) {
    this.ename = ename;
  }
  public String getEpass() {
    return epass;
  }
  public void setEpass(String epass) {
    this.epass = epass;
  }
  public int getEdid() {
    return edid;
  }
  public void setEdid(int edid) {
    this.edid = edid;
  }
  
  public Emp( String ename, String epass, int edid) {
    super();
    this.ename = ename;
    this.epass = epass;
    this.edid = edid;
  }
  
  public Emp(){
    
  }
  
  

}

接口实现类EmpDaoImpl：

package org.dao.impl;

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 org.dao.BaseDao;
import org.dao.IEmpDao;
import org.entity.Dept;
import org.entity.Emp;

import com.sun.corba.se.spi.orbutil.fsm.Guard.Result;

public class EmpDaoImpl implements IEmpDao {

  private Connection conn;
  private PreparedStatement p;
  private ResultSet rs;
  BaseDao base = new BaseDao();
  
  @Override
  public int addEmp(Emp emp) {
    String sql = "insert into Emp(ename,epass,edid) values(?,?,?);";
    List<Object> prama = new ArrayList<Object>();
    prama.add(emp.getEname());
    prama.add(emp.getEpass());
    prama.add(emp.getEdid());
    int rel = 0;
    try {
      rel = base.ExecuteUpdate(sql, prama);
    } catch (SQLException e) {
      e.printStackTrace();
    }finally{
      base.closeConn(conn, p, rs);
    }
    return rel;
  }

  //查询全部
  @Override
  public List<Emp> findEmpAll() {
    String sql = "SELECT * FROM emp ,dept WHERE emp.edid = dept.did";
    List<Emp> eList = new ArrayList<Emp>();
    try {
      rs = base.ExecuteQuery(sql, null);
      while(rs.next()){
        Emp emp = new Emp();
        emp.setEid(rs.getInt("eid"));
        emp.setEname(rs.getString("ename"));
        emp.setEpass(rs.getString("epass"));
        emp.setEdid(rs.getInt("edid"));
        Dept dept = new Dept();
        dept.setDid(rs.getInt("did"));
        dept.setDname(rs.getString("dname"));
        emp.setDept(dept);
        eList.add(emp);
      }
    } catch (SQLException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }finally{
      base.closeConn(conn, p, rs);
    }
    return eList;
  }

  @Override
  public int delEmp(int eid) {
    String sql = "delete from emp where eid = ?;";
    List<Object> prama = new ArrayList<Object>();
    prama.add(eid);
    int rel = 0;
    try {
      rel = base.ExecuteUpdate(sql, prama);
    } catch (SQLException e) {
      e.printStackTrace();
    }finally{
      base.closeConn(conn, p, rs);
    }
    return rel;
  }

  
  @Override
  public Emp findEmpByName(String name) {
    String sql = "select * from Emp where ename =?";
    List<Object> pa= new ArrayList<Object>();
    pa.add(name);
    Emp emp = new Emp();
    try {
      rs = base.ExecuteQuery(sql, pa);
      while(rs.next()){
        emp.setEid(rs.getInt("eid"));
        emp.setEname(rs.getString(2));
        emp.setEpass(rs.getString(3));
        emp.setEdid(rs.getInt("edid"));
      }
    } catch (SQLException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }finally{
      base.closeConn(conn, p, rs);
    }
    return emp;
  }

  //根据部门编号查询
  @Override
  public List<Emp> findEmpByDid(int edid) {
    List<Emp> empList = new ArrayList<Emp>();
    List<Object> param = new ArrayList<Object>();
    String sql = null;
    if(edid!=0){
      sql = "SELECT * FROM emp ,dept WHERE emp.edid = dept.did and edid = ?";
      param.add(edid);
    }else{
      sql = "SELECT * FROM emp ,dept WHERE emp.edid = dept.did";
    }
    try {
      rs = base.ExecuteQuery(sql, param);
      while(rs.next()){
        Emp emp = new Emp();
        emp.setEid(rs.getInt("eid"));
        emp.setEname(rs.getString("ename"));
        emp.setEpass(rs.getString("epass"));
        emp.setEdid(rs.getInt("edid"));
        Dept dept = new Dept();
        dept.setDid(rs.getInt("did"));
        dept.setDname(rs.getString("dname"));
        emp.setDept(dept);
        empList.add(emp);
      }
    } catch (SQLException e) {
      e.printStackTrace();
    }finally{
      base.closeConn(conn, p, rs);
    }
    return empList;
  }

}

Service层接口IEmpService：

package org.service;

import org.dao.IEmpDao;

public interface IEmpService extends IEmpDao {

}

Service层实现类：EmpServiceImpl:

package org.service.impl;

import java.util.List;

import org.dao.IEmpDao;
import org.dao.impl.EmpDaoImpl;
import org.entity.Emp;
import org.service.IEmpService;

public class EmpServiceImpl implements IEmpService {

  IEmpDao empDao = new EmpDaoImpl();
  
  @Override
  public int addEmp(Emp emp) {
    return empDao.addEmp(emp);
  }

  @Override
  public List<Emp> findEmpAll() {
    // TODO Auto-generated method stub
    return empDao.findEmpAll();
  }

  @Override
  public int delEmp(int eid) {
    // TODO Auto-generated method stub
    return empDao.delEmp(eid);
  }

  @Override
  public Emp findEmpByName(String name) {
    // TODO Auto-generated method stub
    return empDao.findEmpByName(name);
  }

  @Override
  public List<Emp> findEmpByDid(int edid) {
    return empDao.findEmpByDid(edid);
  }

}

主要内容在前台jsp页面，我们先来写一个下拉列表，用来存放Dept表中的所有部门名称，当加载该jsp页面时，先从数据库中查询所有部门名称，然后通过jstl遍历至下拉列表中。代码如下：

<%
        IEmpService empService = new EmpServiceImpl();
        List<Emp> empList = empService.findEmpAll();
      request.setAttribute("empList", empList);
      IDeptService deptService = new DeptServiceImpl();
      List<Dept> deptList = deptService.findAllDept();
      request.setAttribute("deptList", deptList);
     %>

部门编号：
  <!-- <input type="text" name="edid"/> -->
     <select id="deptid">
         <option value="0">全部</option>
       <c:forEach items="${deptList }" var="dept">
         <option value="${dept.did }">${dept.dname }</option>
       </c:forEach>
     </select>
     
     <input type="button" id="serch" value="查询"/>

当点击查询按钮时，通过ajax去Servlet中，根据部门编号查询员工信息，在回调函数（success）中处理返回的json数据，遍历动态添加至表格中。

“查询”按钮 的点击事件：

//点击查询查询值
         $("#serch").click(function(){
           //获取部门编号
           //var edid = $("input[name='edid']").val();
           //获取下拉列表中的值
           var edid = $("#deptid").val();
           var data = {"edid":edid,"tag":"getEmpByEdid"};
           $.getJSON("EmpServlet",data,function(data){
             $("#dataTable").html("<tr><td>编号</td><td>姓名</td><td>密码</td><td>部门编号</td><td>操作</td></tr>");
             for(var i in data){
               //给表格中添加数据
               $("#dataTable").append("<tr><td>"
               +data[i].eid+"</td><td>"
               +data[i].ename+"</td><td>"
               +data[i].epass+"</td><td>"
               +data[i].dept.dname+"</td><td><a href='EmpServlet?tag=del&eid="+data[i].eid+"'>删除</a></td></tr>");
             }
           });
         });

数据表格的代码：

<table border="1" id="dataTable">
       <tr>
         <td>编号</td>
         <td>姓名</td>
         <td>密码</td>
         <td>部门名称</td>
      <td>操作</td>
       </tr>
       <c:forEach items="${empList }" var="emp">
         <tr>
           <td>${emp.eid }</td>
           <td>${emp.ename }</td>
           <td>${emp.epass}</td>
           <td>${emp.dept.dname}</td>
        <td>
          <a href="EmpServlet?tag=del&eid=${emp.eid }">删除</a>
        </td>
         </tr>  
       </c:forEach>
     </table>

Servlet类中关键代码：

//根据部门编号查询信息
  public void getEmpByEdid(HttpServletRequest request, HttpServletResponse response) throws IOException{
    Integer edid = Integer.parseInt(request.getParameter("edid"));
    List<Emp> emplist = empService.findEmpByDid(edid);
    String jsonresult = JSON.toJSONString(emplist);
    System.out.println(jsonresult);
    PrintWriter out = response.getWriter();
    out.print(jsonresult);
  }

基本思路就是这样的，怎么样，是不是很简单？