发表时间：2009-03-13
最后修改：2009-03-13
在这里我主要是用了两种方法:
第一种是直接用js来访问,这种方法的优点是简单,但缺点是不能在firefox上使用
第二种是用prototype进行实现,当然对ie和firefox就都能满足了
但不论你是用哪种方法,都会面临一个问题:
由于客户端浏览器的安全设置问题，从客户端JavaScript脚本中用XMLHttpRequest直接访问第三方的网址是被禁止的。
最简单的方法就是在自己的服务器上添加一个代理，客户端脚本先把请求发送给代理，代理转发请求，把响应发回给客户端脚本。
所以,我们先在自己的服务器上添加一个代理
/**
*
*/
package com.sech.web.servlet;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.net.URLConnection;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.lang.StringUtils;
/**
*
* <p>
* Copyright: Copyright (c) 2009
* </p>
*
* @author sech
*
* @version 1.0
*/
public class RssRead extends HttpServlet {
/**
*
*/
private static final long serialVersionUID = 4431127246599359389L;
private static int READ_BUFFER_SIZE = 1024;
/**
*
*/
public RssRead() {
// TODO Auto-generated constructor stub
}
public void init() throws ServletException {
}
// Process the HTTP Get request
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String urlString = request.getParameter("url");
writeResponse(response, urlString);
}
private void writeResponse(HttpServletResponse response, String urlString)
throws ServletException {
try {
URL url = new URL(urlString);
URLConnection urlConnection = url.openConnection();
response.setContentType(urlConnection.getContentType());
InputStream ins = urlConnection.getInputStream();
OutputStream outs = response.getOutputStream();
byte[] buffer = new byte[READ_BUFFER_SIZE];
int bytesRead = 0;
while ((bytesRead = ins.read(buffer, 0, READ_BUFFER_SIZE)) != -1) {
outs.write(buffer, 0, bytesRead);
}
outs.flush();
outs.close();
ins.close();
} catch (Exception e) {
try {
response.sendError(
HttpServletResponse.SC_INTERNAL_SERVER_ERROR, e
.getMessage());
} catch (IOException ioe) {
throw new ServletException(ioe);
}
}
}
// Process the HTTP Post request
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
// Clean up resources
public void destroy() {
}
}
然后再在web.xml中配置下:
<servlet>
<servlet-name>rssread</servlet-name>
<servlet-class>com.sech.web.servlet.RssRead</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>rssread</servlet-name>
<url-pattern>/rssread</url-pattern>
</servlet-mapping>
这样我们就可以直接访问:http://localhost/rssread 了
既然已经建立了服务器代理,那下面我们就进行js的编写.
第一种:
function get_news(servername)
{
var URL,i;
var s_wz,e_wz,str,htmlText;
htmlText = "";
URL = servername+"rssread?url=http://news.sohu.com/rss/shehui.xml";
var xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
xmlDoc.async=false;
xmlDoc.load(URL);
nodes = xmlDoc.documentElement.childNodes;
var ItemN = xmlDoc.getElementsByTagName("item");
for(i=0;i<7;i++)
{
TextTitle = ItemN[i].selectSingleNode("title").text;//获取title内容
TextLink = ItemN[i].selectSingleNode("link").text;//获取link内容
//Textdescription = ItemN[0].selectSingleNode("description").text;
//s_wz = Textdescription.indexOf("src='");
//e_wz = Textdescription.indexOf("'",s_wz+5);
//Imgurl = Textdescription.slice(s_wz+5,e_wz);
htmlText = htmlText + "<LI><a href='"+TextLink+"' target=_blank>"+TextTitle+"</a></LI>"
}
return htmlText;
}
html的调用:
<DIV class=textDiv id="news">
<UL>
<script language="JavaScript">
document.writeln(sendRequest('http://localhost/'))
</script>
</UL>
</DIV>
第二种方法:
var SendRequestAjax = Class.create();
SendRequestAjax.prototype ={
initialize: function(servername) {
this.servername = servername;
},
sendRequest:function(){
var url =this.servername+"rssread?url=http://news.sohu.com/rss/shehui.xml";
var pars = "";
var myAjax = new Ajax.Request(url, {method: 'get', parameters: pars, onComplete: this.sendRequestCompleted.bind(this)});
},
sendRequestCompleted:function(res){
var results= res.responseXML;
var title = null;
var item = null;
var link = null;
var htmlText="";
var items = results.getElementsByTagName("item");
for(var i = 0; i < 7; i++) {
item = items[i];
link=items[i].getElementsByTagName("link")[0].firstChild.nodeValue;
title = items[i].getElementsByTagName("title")[0].firstChild.nodeValue;
htmlText = htmlText + "<LI><a href='"+link+"' target=_blank>"+title+"</a></LI>"
}
$("news").innerHTML="<UL>"+htmlText+"</UL>";
}
};
function sendRequest(servername) {
var oSendRequestAjax = new SendRequestAjax(servername);
oSendRequestAjax.sendRequest();
}
html代码:
<script type="text/javascript" src="js/prototype.js"></script>
<DIV class=textDiv id="news">
<script language="JavaScript">
(sendRequest('http://localhost/'))
</script>
</DIV>
OK.这样两种方法就都搞定了.
