Ajax添加省份到下拉框里

一、jsp页面

<select name="province" >
         <option>请选择省份：</option>
</select>

 

$(function(){
 //第一步：创建XMLHttpRequest对象
 var xmlhttp;
 if (window.XMLHttpRequest){
   xmlhttp=new XMLHttpRequest();
   }
 else{
   xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
   }
 //第二步：调用open()
 xmlhttp.open("GET","${pageContext.servletContext.contextPath}/cityServlet.do?method=chooseCity",true);
//第三步：调用send() 
xmlhttp.send();
//第四步 
 xmlhttp.onreadystatechange = function(){
  if (xmlhttp.readyState==4){
   if(xmlhttp.status==200){
       var city = xmlhttp.responseText;
       var provinces = city.split(",");
       for(var i = 0 ; i<provinces.length-1 ; i=i+2){
        var opt = new Option(provinces[i+1],provinces[i]);
        $("select[name='province']").append(opt); 
       }
     }else{
      alert("错误");
     }
  }
 };
});

  

二、CityServlet.java(继承HttpServlet、重写方法、配置xml)

response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
out.print("01,山西,02,山东,03,河北");