ajax实现通过empno不刷新网页查询emp数据表对象（使用JSON）
JSP
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<%@include file="commons/basePath.jsp" %>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>查员工</title>
<script type="text/javascript" src="js/createXHR.js"></script>
<script type="text/javascript">
function find(){
var empno = document.getElementById("empno").value.trim();
createXHR();
xhr.open("POST","findEmp");
xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
xhr.onreadystatechange=function(){
if(xhr.readyState==4&&xhr.status==200){
var date = xhr.responseText;
var obj = JSON.parse(date);
document.getElementById("ename").value=obj.ename;
document.getElementById("job").value=obj.job;
document.getElementById("sal").value=obj.sal;
document.getElementById("hiredate").value=obj.hiredate;
document.getElementById("dept").value=obj.deptno;
}
}
xhr.send("empno="+empno);
}
</script>
</head>
<body>
<p>员工编号:<input id="empno">
<input type="button" value="查询" onclick="find()">
</p>
<hr>
<div>
<p>姓名<input id="ename"></p>
<p>职位<input id="job"></p>
<p>薪水<input id="sal"></p>
<p>雇佣日期<input type="date" id="hiredate"></p>
<p>
部门名<select id="dept">
<option value="10">ACCOUNTING</option>
<option value="20">RESEARCH</option>
<option value="30">CHICAGO</option>
</select>
</p>
</div>
</body>
</html>
servlet（QueryTableDAO这个不用在意，这是我通过反射写的单表查询万能dao，就当他是个普通的dao方法就可以了）
package top.yibobo.web.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Date;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import net.sf.json.JSONObject;
import net.sf.json.JSONSerializer;
import net.sf.json.JsonConfig;
import top.yibobo.pojo.Emp;
import top.yibobo.util.DateValueProcessor;
import top.yibobo.util.QueryTableDAO;
@WebServlet("/findEmp")
public class EmpServlet extends HttpServlet{
QueryTableDAO empdao = new QueryTableDAO("emp_pyb", Emp.class);
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req, resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("utf-8");
resp.setCharacterEncoding("utf-8");
String empno = req.getParameter("empno");
System.out.println(empno);
Emp e = empdao.findSingle("empno", empno);
JsonConfig config = new JsonConfig();
config.registerJsonValueProcessor(Date.class, new DateValueProcessor());
JSONObject jo = (JSONObject) JSONSerializer.toJSON(e,config);
PrintWriter out = resp.getWriter();
out.println(jo);
out.close();
}
}
