window.onload = function(){
var xmlHttp = createXMLHttpRequest();
xmlHttp.open("GET","<c:url value='/ProvinceServlet'/>",true);
xmlHttp.send(null);
xmlHttp.onreadystatechange = function(){
if (xmlHttp.readyState == 4 && xmlHttp.status == 200) {
var text = xmlHttp.responseText;
var proArray = eval("("+text+")");
//document.write(xmlHttp.readyState);
//document.write(xmlHttp.status == 200);
for(var i=0;i<proArray.length;i++){
var pro = proArray[i];
var option = document.createElement("option");
option.value = pro.pid;
var node = document.createTextNode(pro.name);
option.appendChild(node);
document.getElementById("p").appendChild(option);
}
}else {
document.write(xmlHttp.readyState==4);
document.write(xmlHttp.status == 200);
}
};
};
xmlHttp.status == 200 输出是true，但是xmlHttp.readyState==4输出是false。
以下是servlet的代码：
public class ProvinceServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
Dao dao = new Dao();
List<Province> listProvinces = dao.findAllProvince();
String jsonProvince = JSONArray.fromObject(listProvinces).toString();
response.getWriter().print(jsonProvince);
}
}
