ajax.jar实例代码

package com.briup.web; import java.io.IOException; import java.io.PrintWriter; import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.TreeMap; import javax.servlet.RequestDispatcher; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class OptionServlet extends HttpServlet { private Map<String,List<String>> options=new TreeMap<String,List<String>>(); public void init(){ List<String> list1=new ArrayList<String>(); list1.add("请选择"); options.put("0", list1); List<String> list2 =new ArrayList<String>(); list2.add("宁波"); list2.add("杭州"); list2.add("嘉兴"); options.put("1", list2); List<String> list3=new ArrayList<String>(); list3.add("苏州"); list3.add("南京"); list3.add("无锡"); options.put("2", list3); List<String> list4=new ArrayList<String>(); list4.add("杨浦区"); list4.add("黄浦区"); list4.add("徐汇区"); options.put("3", list4); } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String province =request.getParameter("province"); List<String> cities =options.get(province); request.setAttribute( "cities", cities); RequestDispatcher rd =request.getRequestDispatcher( "result.jsp"); rd.forward(request, response); } }