Proxy.java

package proxy;
 
import java.io.*;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Map;
import java.util.List;
import java.util.logging.*;
 
import javax.servlet.*;
import javax.servlet.http.*;
 
import java.net.URL;
import java.net.HttpURLConnection;
 
public class Proxy extends HttpServlet {
 
    private ServletContext servletContext;
    private Logger log;
 
    public void init(ServletConfig servletConfig) throws ServletException {
        servletContext = servletConfig.getServletContext();
        log = Logger.getLogger(Proxy.class.getName());
    }
 
    public void doGet(HttpServletRequest request, HttpServletResponse response){
        doPost(request, response);
    }
 
    public void doPost(HttpServletRequest request, HttpServletResponse response){
 
        BufferedInputStream webToProxyBuf = null;
        BufferedOutputStream proxyToClientBuf = null;
        HttpURLConnection con;
 
        try{
            int statusCode;
            int oneByte;
            String methodName;
            String headerText;
 
            String urlString = request.getRequestURL().toString();
            String queryString = request.getQueryString();
 
            urlString += queryString==null?"":"?"+queryString;
            URL url = new URL(urlString);
 
            log.info("Fetching >"+url.toString());
 
            con =(HttpURLConnection) url.openConnection();
 
            methodName = request.getMethod();
            con.setRequestMethod(methodName);
            con.setDoOutput(true);
            con.setDoInput(true);
            con.setFollowRedirects(false);
            con.setUseCaches(true);
 
            for( Enumeration e = request.getHeaderNames() ; e.hasMoreElements();){
                String headerName = e.nextElement().toString();
                con.setRequestProperty(headerName,    request.getHeader(headerName));
            }
 
            con.connect();
 
            if(methodName.equals("POST")){
                BufferedInputStream clientToProxyBuf = new BufferedInputStream(request.getInputStream());
                BufferedOutputStream proxyToWebBuf     = new BufferedOutputStream(con.getOutputStream());
 
                while ((oneByte = clientToProxyBuf.read()) != -1) 
                    proxyToWebBuf.write(oneByte);
 
                proxyToWebBuf.flush();
                proxyToWebBuf.close();
                clientToProxyBuf.close();
            }
 
            statusCode = con.getResponseCode();
            response.setStatus(statusCode);
 
            for( Iterator i = con.getHeaderFields().entrySet().iterator() ; i.hasNext() ;){
                Map.Entry mapEntry = (Map.Entry)i.next();
                if(mapEntry.getKey()!=null)
                    response.setHeader(mapEntry.getKey().toString(), ((List)mapEntry.getValue()).get(0).toString());
            }
 
            webToProxyBuf = new BufferedInputStream(con.getInputStream());
            proxyToClientBuf = new BufferedOutputStream(response.getOutputStream());
 
            while ((oneByte = webToProxyBuf.read()) != -1) 
                proxyToClientBuf.write(oneByte);
 
            proxyToClientBuf.flush();
            proxyToClientBuf.close();
 
            webToProxyBuf.close();
            con.disconnect();
 
        }catch(Exception e){
            System.out.println(e.getMessage());
            e.printStackTrace();
        }
        finally{
        }
    }
}