AJAX解析XML实例之下拉框二级联动

这个例子是实现省、市二级联动，当选择某一省时，改省下面的市就会在另一个下拉框显示出来。在本例中AJAX通过解析XML文件得到的数据传回到jsp页面，其中省市均是从数据库取到的值：

jsp页面代码：

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>



  
  
  
  
    省：
    请选择
    
    市：
    
    
  

servlet代码：

public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		request.setCharacterEncoding("utf-8");
		String province=request.getParameter("province");
		if(province!=null){
			sendCity(request,response,province);
		}else{
		ShengDao sd=new ShengDao();
		List list=sd.selAll();
		response.setCharacterEncoding("utf-8");
		PrintWriter out=response.getWriter();
		response.setContentType("text/xml");
		out.println("");
		out.println("");
		for (Sheng sheng : list) {
			out.print(""+sheng.getProvince()+"");
			out.println();
		}
		out.println("");
	}
	}
	
	public void sendCity(HttpServletRequest request, HttpServletResponse response,String shorter){
		try {
			request.setCharacterEncoding("utf-8");
		} catch (UnsupportedEncodingException e1) {
			e1.printStackTrace();
		}
		try {
			response.setCharacterEncoding("utf-8");
			PrintWriter out=response.getWriter();
			response.setContentType("text/xml");
			ShengDao sd=new ShengDao();
			List list=sd.selAll(shorter);
			out.println("");
			out.println("");
			for (City city : list) {
				out.println(""+city.getCityname()+"");
				System.out.println(""+city.getCityname()+"");
			}
			out.println("");
		} catch (IOException e) {
			e.printStackTrace();
		}
	}