总觉得哪里写的不对，老师帮忙看看。。。

package com.imooc.ajax.test;
/**
 * 员工类
 * @author 888
 *
 */
public class Employee {
private String name;//名字
private String job;//职务
private String department;//部门
public Employee() {
}
public Employee(String name,  String job,String department) {
super();
this.name = name;
this.department = department;
this.job = job;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDepartment() {
return department;
}
public void setDepartment(String department) {
this.department = department;
}
public String getJob() {
return job;
}
public void setJob(String job) {
this.job = job;
}
}

package com.imooc.ajax.test;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
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 com.alibaba.fastjson.JSON;
@WebServlet("/emp")
public class EmployeeServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
List list=new ArrayList();
list.add(new Employee("小红","职员","人事部"));
list.add(new Employee("小明","经理","技术部"));
list.add(new Employee("小白","职员","无线事业部"));
String json=JSON.toJSONString(list);
response.setContentType("text/html;charset=UTF-8");
response.getWriter().println(json);
}
}

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<div align="center">
<input style="width: 200px" id="inp1"  type="button" value="员工列表">
<input style="width: 200px" id="inp2" type="button" value="职位列表">
<input style="width: 200px" id="inp3" type="button" value="部门列表">
</div>
<div id="content" align="center"></div>
<script type="text/javascript">
var xmlhttp;
if(window.XMLHttpRequest){
xmlhttp=new XMLHttpRequest();
}else{
smlhttp=new ActiveXOject("Microsoft","XMLHTTP");
}
xmlhttp.open("GET","/ajax/emp",true);
xmlhttp.send();
xmlhttp.onreadystatechange=function(){
if(xmlhttp.readyState==4&&xmlhttp.status==200){
var text=xmlhttp.responseText;
var json=JSON.parse(text);
//员工列表
document.getElementById("inp1").onclick=function(){
var html="";
for(emp in json){
html+=json[emp].name+"<br>";
}
document.getElementById("content").innerHTML=html;
}
//职位列表
document.getElementById("inp2").onclick=function(){
var html="";
var num=0;
for(emp in json){
var job=json[emp].job;
if(job=='职员'){
num++;
}
if(num>1){
job="";
}
html+=job+"<br>";
}
document.getElementById("content").innerHTML=html;
}
//部门列表
document.getElementById("inp3").onclick=function(){
var html="";
for(emp in json){
html+=json[emp].department+"<br>";
}
document.getElementById("content").innerHTML=html;
}
}
}
</script>
</body>
</html>