iframe拒绝访问 java 读取网页内容

昨天，在应用开发中，遇到了一个iframe跨域拒绝访问的问题，在网上找了半天，最后，决定使用java重定向读取网页内容显示的办法解决，可是在java读取网页内容的时候，有碰到了乱码问题，网上也有好多的解决办法，可是都不适用，琢磨到今天，终于解决了，先贴出来，与大家分享一下。

关键语句在于：new InputStreamReader(conn.getInputStream(),
                 conn.getContentEncoding()!=null?conn.getContentEncoding():"UTF-8"))。

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
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 GetHtmlContentByURL extends HttpServlet {

private static final long serialVersionUID = 1L;

public GetHtmlContentByURL() {
   super();
}

public void destroy() {
   super.destroy();
}

public void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
   String htmlUrl = request.getParameter("url");
   response.setCharacterEncoding("UTF-8");
   URL url = null;
   URLConnection conn = null;
   PrintWriter out = null;
     try { 
         out = response.getWriter();
         url = new URL(htmlUrl);
         conn = url.openConnection();
         //将网页文件默认设置为UTF-8字符集，
           BufferedReader reader = new BufferedReader(
               new InputStreamReader(conn.getInputStream(),
                 conn.getContentEncoding()!=null?conn.getContentEncoding():"UTF-8"));
            String line = null;
            while ((line=reader.readLine()) != null){
                out.println(line);
            }

        out.flush();
        reader.close();
     } catch (Exception ex) {   
         ex.printStackTrace();
     } finally { 
     if(out!=null){
        try{
         out.close();
        }catch(Exception e){
         e.printStackTrace();
        }
     }
     } 
}

public void doPost(HttpServletRequest request, 
                    HttpServletResponse response) 
                        throws ServletException, IOException {
   this.doGet(request, response);
}

public void init() throws ServletException {}
}