Ajax 请求的处理

function ajaxTest() {


/* 1.创建XHR */
var xmlhttp;
if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp = new XMLHttpRequest();
} else {// code for IE6, IE5
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
/* 4.监听 */
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4) {
if (xmlhttp.status == 200) {
alert(xmlhttp.responseText);
//alert("OK");
}
/* if (xmlhttp.status == 404) {
alert(xmlhttp.responseText);
//alert("OK");
} */
}
}
/* 2.创建请求连接 */
xmlhttp.open("get", "demo1", true);
/* 3. */
xmlhttp.send(null);
}
//ajaxTest();

function getTest() {
$.get("demo2",
"name=tom",
function(data){
alert(data);
},
"text");
}
//getTest();
function postTest() {
$.post("demo3",
"name=jerry",
function(data){
alert(data);
},
"text");
}
//postTest();
function $ajaxTest(){
$.ajax({
url:"demo4",
type:"post",
data:{"name":"laowang","pwd":"1234"},
dataType:"json",
success:function(data){
$("#div1").html("");
$("#div1").append(data[1]+"<br/>");
}
});

}

@WebServlet("/demo4")
public class Demo4 extends HttpServlet{
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
String name = req.getParameter("name");
String pwd = req.getParameter("pwd");
System.out.println(name+"\t"+pwd);
List<String> list = new ArrayList<String>();
list.add("a");
list.add("b");
list.add("c");
list.add("d");
String jsonString = JSON.toJSONString(list);
resp.getWriter().write(jsonString);
}
}