用js直接读取Rss新闻的两种方法
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。
/** * */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 requestpublic 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 requestpublic void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}// Clean up resourcespublic void destroy() {}}<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