jquery json实现二级动态联动

以下为代码！需要导入json架包

function getCity1(){
		var unitid = document.getElementById('addformunitid').value;
		
		
		   $.getJSON("../unit/getcity.do?unitid="+unitid, "", function(response){
		   //$ ("#departmentid").show();//将隐藏的select显示出来
		   $ ("#adddepartmentid option").remove();//将select中的信息清空
		   $ ("#adddepartmentid").attr("disabled",false);
		   //alert(response);
			   
             
			$.each(response,function(i){ 
			     //encodeURI(response[i]);
				//encodeURI(fileName)
				//将后台传回的信息打印到页面中
   	     	    $ ("#adddepartmentid").append ("<option value="+response[i].id+">"+ response[i].departmentname +"</option>");
			});
		});
		
    	
 }

<tr> 
				<td class="td_title">所属单位<em>*</em></td>
				<td>
					<select name="eform.unitid"   id="addformunitid"  onChange="getCity1();">
						<option value="0">请选择</option>
						<#list unitList as ul>
							<option value="${ul.id}">${ul.unitname}</option>
						</#list>
					</select>
				</td>
				<td class="td_title">部门<em>*</em></td>
				<td>
					<select name="eform.departmentid" id="adddepartmentid" disabled="disabled">
					    <option value=" ">请选择</option>
					</select>
				</td>
				 <td class="td_title">职位<em>*</em></td>
				<td>
					<select name="eform.positionid">
					<option value=" ">请选择-</option>
						<#list positionList as pl>
							<option value="${pl.id}">${pl.positionname}</option>
						</#list>
					</select>
				</td>
			</tr>

        <!-- 单位，部门二级联动 -->

        <package name="unit" extends="webwork-default" namespace="/unit">
		<action name="getcity" class="com.hnbus.action.unit.EmployeeJsonAction"  method="getcity" >
			<interceptor-ref name="defaultStack"/>
		</action>
		
	</package>

/*
 *文件名:EmployeeJsonAction.java
 *描  述:二级联动action
 *版  权:********有限公司 Copyright (c) 2008-2013,All Rights Reserved.
 *创建者:向洁
 *修改者:向洁
 */

package com.hnbus.action.unit;

import java.io.PrintWriter;
import java.net.URLDecoder;
import java.util.List;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletResponse;

import net.sf.json.JSONArray;

import org.apache.log4j.Logger;
import org.eps.action.BaseAction;

import com.hnbus.model.Department;
import com.hnbus.model.Employee;
import com.hnbus.service.unit.EmployeeService;
import com.opensymphony.webwork.ServletActionContext;
/**
 * @Description (二级联动action)
 * @author   向洁
 * @version  JOHOM V1.0
 * @Date	 2013-8-4-下午10:54:05
 * @see 	 
 */
public class EmployeeJsonAction  extends BaseAction{
	
	private static final Logger logger = Logger.getLogger(EmployeeAction.class);
	
	@Resource
	private EmployeeService employeeService;
	private EmployeeForm1 eform;
	private String unitid;
	
	
	public String getcity() throws Exception {
		logger.info("选择单位ID");
		//获取前台传来的值
		String unitid = this.getRequest().getParameter("unitid");
		
        HttpServletResponse response = ServletActionContext.getResponse();
        /*设置字符集为'UTF-8'*/
        response.setContentType("text/plain;charset=utf-8"); 
		List<Department> department = employeeService.findSameDepartmentlist(unitid);
        ServletActionContext.getRequest().getSession().setAttribute("department",department);
        
		//将list转换成JSON对象
	    JSONArray jr = JSONArray.fromObject(department);
	    PrintWriter out = this.getResponse().getWriter(); 
		//将JSON对象转换成String类型传入前台
		String jsonUser = jr.toString(); 
		out.print(jsonUser);	
		out.flush();
		out.close();			
		return null;
	}

	/**
	 * 变量:employeeService
	 * @return 变量:employeeService
	 */
	public EmployeeService getEmployeeService() {
		return employeeService;
	}
	
	/**
	 * 变量:eform
	 * @return 变量:eform
	 */
	public EmployeeForm1 getEform() {
		return eform;
	}

	/**
	 * 变量:eform
	 * @param eform (Set the variable:eform)
	 */
	public void setEform(EmployeeForm1 eform) {
		this.eform = eform;
	}

	/**
	 * 变量:employeeService
	 * @param employeeService (Set the variable:employeeService)
	 */
	public void setEmployeeService(EmployeeService employeeService) {
		this.employeeService = employeeService;
	}

	/**
	 * 变量:logger
	 * @return 变量:logger
	 */
	public static Logger getLogger() {
		return logger;
	}
	
	/**
	 * 变量:unitid
	 * @return 变量:unitid
	 */
	public String getUnitid() {
		return unitid;
	}

	/**
	 * 变量:unitid
	 * @param unitid (Set the variable:unitid)
	 */
	public void setUnitid(String unitid) {
		this.unitid = unitid;
	}
	
}
class EmployeeForm1 extends Employee{}