当服务器返回xml文件时则可以使用responseXML方式获取数据
第一步：服务器返回xml的方式：
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
Random r = new Random();
int a = r.nextInt(20);
//查询学生
List<Stud> ss = new ArrayList<Stud>();
for(int i=0;i<a;i++){
Stud s = new Stud("S"+i,"Jack"+i,i);
ss.add(s);
}
//request.setAttribute("ss",ss);
//request.getRequestDispatcher("/server/stud.jsp").forward(request, response);
String xml = "<?xml version="1.0" encoding="UTF-8"?><studs>";
for(Stud s:ss){
xml+="<stud id=""+s.getId()+"">" +
"<name>"+s.getName()+"</name>" +
"<age>"+s.getAge()+"</age>" +
"</stud>";
}
xml+="</studs>";
response.setContentType("text/xml;charset=UTF-8");
response.getWriter().print(xml);
}
或是封装到request中以后在jsp页面上，让jsp帮助你组织：
<%@ page language="java" contentType="text/xml" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<?xml version="1.0" encoding="UTF-8"?>
<studs>
<c:forEach items="${ss}" var="s">
<stud id="${s.id}">
<name>${s.name}</name>
<age>${s.age}</age></stud>
</c:forEach></studs>
第二步：在JS客户端用JSDOM解析返回的XML
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<style type="text/css">
table{
border-collapse:collapse;
}
table td{
border:1px solid black;
}
</style>
<script type="text/javascript" src="<c:url value='/js/ajax.js'/>"></script>
<script type="text/javascript">
function _search(){
var url = "<c:url value='/QueryServlet'/>";
xhr.open("GET",url);
xhr.onreadystatechange=function(){
if(xhr.readyState==4){
if(xhr.status==200){
//此方法是获取任何数据都是可的。只不过类型是string
//可以通过此方法检查是否返回的数据为正确的数据
var xml = xhr.responseXML;//返回的就成了一个dom对象
//获取所有stud元素
var studs = xml.getElementsByTagName("stud");
alert(studs);//显示一个对象
alert(studs.length);
for(var i=0;i<studs.length;i++){
//获取第几个属性
var id = studs[i].attributes(0).value;
var name = studs[i].childNodes(0);
name = name.firstChild.data;
var age = studs[i].childNodes(1);
age = age.firstChild.data;
//将新生写到第一行
var tr = aa.insertRow();
var td = tr.insertCell();
td.innerHTML=id;
var td = tr.insertCell();
td.innerHTML=name;
var td = tr.insertCell();
td.innerHTML=age;
}
}
}
};
xhr.send();
}
</script>
</head>
<body>
<button onclick="_search();">查询</button>
<table id="aa" style="width:400px;border:1px solid red;">
<tr>
<td>ID</td>
<td>NAME</td>
<td>AGE</td>
</tr>
</table>
</body>
</html>
第三步：解析网上的xml服务;
（1）获取网上的一个服务地址：
（2）步测试：成功
（3）查看调用方式
(4) 代码
<script type="text/javascript">
function _search(){
//1:f声明url
var url = "http://webservice.webxml.com.cn/WebServices/MobileCodeWS.asmx";
//2:打开
xhr.open("POST",url);
//3:设置请求头
xhr.setRequestHeader("Content-Type","text/xml; charset=utf-8");
//4:设置状态变化调用方法
xhr.onreadystatechange=function(){
if(xhr.readyState==4){
if(xhr.status==200){
var xml = xhr.responseXML;
alert(xml);
var ns = xml.getElementsByTagName("getMobileCodeInfoResult");
//获取手机信息
var msg = ns[0].firstChild.data;
//alert(msg);
document.getElementById("msg").innerHTML=msg;
}
}
};
//获取用户的输入的电话
var code = document.getElementsByName("code")[0].value;
//5:声明xml数据
var xml = '<?xml version="1.0" encoding="utf-8"?>'+
'<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"'+
' xmlns:xsd="http://www.w3.org/2001/XMLSchema" '+
'xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">'+
'<soap:Body><getMobileCodeInfo xmlns="http://WebXml.com.cn/">'+
'<mobileCode>'+code+'</mobileCode><userID></userID>'+
'</getMobileCodeInfo></soap:Body></soap:Envelope>';
//6:请求
xhr.send(xml);
}
</script>
第四步：有没有ajax的情况下调用
用java代码也可以调用：
Urlconnection
@Test
public void aa() throws Exception{
Scanner sc = new Scanner(System.in);
String code = sc.nextLine();
URL url = new URL("http://webservice.webxml.com.cn/WebServices/MobileCodeWS.asmx");
HttpURLConnection con =
(HttpURLConnection) url.openConnection();
con.setRequestMethod("POST");
con.setRequestProperty("Content-Type","text/xml;charset=UTF-8");
con.setDoInput(true);
con.setDoOutput(true);
InputStream in = TestDemo.class.getResourceAsStream("a.xml");
ByteArrayOutputStream bout = new ByteArrayOutputStream();
int len = 0;
byte[] b = new byte[1024];
while((len=in.read(b))!=-1){
bout.write(b,0,len);
}
String xml = new String(bout.toByteArray(),"UTF-8");
xml=xml.replace("${code}",code);
con.getOutputStream().write(xml.getBytes("UTF-8"));
int status = con.getResponseCode();
System.err.println(status);
//从服务器读取数据
in = con.getInputStream();
while((len=in.read(b))!=-1){
String s = new String(b,0,len);
System.err.print(s);
}
in.close();
con.disconnect();
}
