AJAX处置以XML返回的响应

AJAX处理以XML返回的响应

Ajax请求，服务器端返回XML形式的数据，在页面上用Javascript处理会非常方便。

代码：

// 发送请求
var req;
		
function getXMLHttpRequest() {
	var xRequest = null;
	if (window.XMLHttpRequest) {
		xRequest = new XMLHttpRequest();
	} else if (typeof ActiveXObject != "undefined") {
		xRequest = new ActiveXObject("Microsoft.XMLHTTP");
	}
	return xRequest;
}
		
function sendRequest(url, params, HttpMethod, callback) {
	if (!HttpMethod) {
		HttpMethod = "GET";
	}
	req = getXMLHttpRequest();
	if (req) {
		req.onreadystatechange = callback;
		req.open(HttpMethod,url,true);
		req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded; charset=EUC-JP"); 
		req.send(params);
	}
}

// 回调函数
function change() {
            if (xmlHttp.readyState == 4) {
                if (xmlHttp.status == 200) {
                    var data = xmlHttp.responseXML;
                    var datas = data.getElementsByTagName('info');
                    for (var i = 0; i < datas.length; i++) alert(datas[i].firstChild.nodeValue);
                    datas = data.getElementsByTagName('memo');
                    for (i = 0; i < datas.length; i++) alert(datas[i].firstChild.nodeValue);
                }
            }
        }

// 服务器端代码

// XML头，没有这个Javascript解析不出XML，编码一定要设，要不然会乱码
StringBuilder infoBuilder = new StringBuilder("<?xml version=\"1.0\" encoding=\"EUC-JP\"?>");
// 根元素<root></root>一定需要，否则Javascript解析不出XML，但名字不一定要叫root
infoBuilder.append(("<root><info>a</info><info>b</info><memo>c</memo><memo>d</memo></root>");
);

PrintWriter writer = null;
		try {
			
			// 设置编码
response.setContentType("text/xml;charset=EUC-JP");
			writer = response.getWriter();
			writer.println(infoBuilder.toString());
			writer.flush();
		} catch (Exception e) {
			
		} finally {
			if (writer != null) writer.close();
		}