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經(jīng)過(guò)多番努力，問(wèn)題終于得到解決。感謝校長(zhǎng)的提示。
在此說(shuō)明解決方法： 同樣類(lèi)似使用代理的意念，在java內(nèi)寫(xiě)一個(gè)servlet來(lái)處理這個(gè)問(wèn)題。
詳細(xì)處理方式是：1.首先，同樣使用xmlhttp方式處理；
2.然后，在進(jìn)行open提交的時(shí)候，不直接提交到對(duì)應(yīng)數(shù)據(jù)源所在的URL地址。而是提交到代理程序，而通過(guò)代理程序打開(kāi)需要讀取的數(shù)據(jù)源URL,同時(shí)處理讀取并返回。
3.最后，重新用xmlhttp進(jìn)行解析顯示處理即可以實(shí)現(xiàn)跨域讀取RSS源。
修改上面的js代碼：
var PROXY_SERVLET_URL="../../proxyServlet?url=";//對(duì)應(yīng)配置的servlet參數(shù)
if(url.toLowerCase().indexOf("[url=http://]http://")==-1[/url]){
readRSS(url);
}else{
url = PROXY_SERVLET_URL + url;
readRSS(url);
}
java源代碼如下：
package action;
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;
public class ProxyServletUtil extends HttpServlet {
/**
*
*/
private static final long serialVersionUID = 1L;
private int READ_BUFFER_SIZE = 1024;
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);
}
System.out.println(outs);
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);
}
}
}
}
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