Thread: Implementing a webproxy

HI,,I am currently writting a web proxy in java.The problem that I currently have is that my http response keeps hanging..Can anyone please spot the error in my code.

import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
 
 
 
 
public class Server  {
	ServerSocket proxyserver=null;
	InetSocketAddress adr;
 
	ClientHandler handler;
	Socket socket;
 
	public Server(){
 
		adr= new InetSocketAddress("localhost",8088);
    	try {
			proxyserver= new ServerSocket();
			proxyserver.bind(adr);
			System.out.println("Serversocket created");
		} catch (IOException e) {
 
			e.printStackTrace();
		}
	}
	public static void main(String[] args) {
		Server server= new Server();
		server.run();
	}
 
 
	public void run() {
 
 
 
		while(true){
		try {
			 System.out.println("Waiting for connection to be made to proxy server");
			//socket= proxyserver.accept();
 
			  new Thread( new ClientHandler(proxyserver.accept())).start();  // calls the start method to start a thread which also starts the run method
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		}
 
	}
}
 
 
 
import java.net.*;
import java.io.*;
 
public class ClientHandler implements Runnable{
	Socket socket;
	Socket serverSocket;
	private InputStream clientinput;
	private OutputStream clientoutput;
	private HttpRequest httprequest;
	private HttpResponse httpresponse;
	BufferedWriter toClient;
    BufferedWriter toServer;
 
 
    public ClientHandler(Socket socket){
		this.socket=socket;
 
 
		  System.out.println("Accepted a request!\n" + httprequest);
		  try {
				this.clientinput=socket.getInputStream();
 
				this.clientoutput=socket.getOutputStream();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			httprequest= new HttpRequest(clientinput);
	}
 
	@Override
	public void run() {
		while (true){
			try{
			  System.out.println("Accepted a request!\n" + httprequest);
			  while(httprequest.busy);
			    URL url = null;
                try {
                    url = new URL(httprequest.getRequestURL());
                } catch (MalformedURLException e){
                    try {
						url = new URL("http:\\"+httprequest.getRequestHost()+httprequest.getRequestURL());
					} catch (MalformedURLException e1) {
						// TODO Auto-generated catch block
						e1.printStackTrace();
					}
                }
 
           //     {
                int remotePort = (url.getPort() == -1) ? 80 : url.getPort();
                System.out.println("I am going to try to connect to: " + url.getHost() + " at port " + remotePort);
 
					serverSocket = new Socket(url.getHost(), 80);
					 System.out.println("Connected to tcd proxy"+ serverSocket.getLocalAddress());
 
 
 
 
                //write to the server - keep it open.
                System.out.println("Writing to the server's buffer...");
 
					toServer = new BufferedWriter(new OutputStreamWriter(serverSocket.getOutputStream()));
 
					toServer.write(httprequest.getFullRequest());
 
 
					toServer.flush();
 
                System.out.println("flushed.");
 
 
 
                System.out.println("Getting a response...");
 
					httpresponse = new HttpResponse(serverSocket.getInputStream());
 
                System.out.println("Got a response!\n" + httpresponse);
              while(httpresponse.isBusy());   
              //         }
 
 
                toClient = new BufferedWriter(new OutputStreamWriter(clientoutput));
 
					toClient.write(httpresponse.getFullResponse());
					toClient.flush();
		            toClient.close();
		            this.socket.close();
			}
			catch (IOException e) {
                e.printStackTrace();
                continue;
            }
 
 
		}//while
 
	}
 
}
 
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
 
 public class HttpResponse{
        private String fullResponse = "";
        private BufferedReader reader;
        private boolean busy=true; 
    //    private int responseCode;
    //    private CacheControl cacheControl;
 
        public HttpResponse(String input) {
            this(new ByteArrayInputStream(input.getBytes()));
        }
 
        public HttpResponse(InputStream input) {
        	//busy=true;
            reader = new BufferedReader(new InputStreamReader(input));
            try {
                while (!reader.ready());//wait for initialization.
 
                String line;
                while ((line = reader.readLine()) != null) {
                    fullResponse += "\r\n" + line;
 
              //System.out.println("hellooo  " +fullResponse);
                }
                reader.close();
                fullResponse = "\r\n" + fullResponse.trim() + "\r\n\r\n";
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } 
            busy = false;
        }
 
 
 
        public String getFullResponse() {
            return fullResponse;
        }
 
        public boolean isBusy() {
            return busy;
        }
 
 
 
        //@Override
        public String toString() {
            return "Response\n==============================\n" + fullResponse;
        }
    }
 
 
 
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
 
 
  /*This class is used to take in a stream which contains a Http request and produce parse valuable information form
    like host name
    url
    The http request would be get request in this case
    */
  public class HttpRequest{
	 private BufferedReader request; // bufferedreader
	 String httpfullrequest="";
	 private String httprequestHost;
     private String httprequestURL;
     public boolean busy=true;
 
 
     public HttpRequest(String input) {
         this(new ByteArrayInputStream(input.getBytes()));
     }
     public HttpRequest( InputStream inputstream){
         request = new BufferedReader(new InputStreamReader(inputstream));
 
         parserequest();
     }
 
     /*
      * This private function parses a request 
      */
     private void parserequest(){
 
           try {
               while (!request.ready());//wait for buffer not to be empty
 
               String line;
               while ((line = request.readLine()) != null) {
                   if(!line.startsWith("Accept-Encoding:")) httpfullrequest += "\r\n" + line;
                   if(line.startsWith("GET ")){httprequestURL=line.split(" ")[1];System.out.println("url \""+httprequestURL+"\"");}
                   if(line.startsWith("Host:")){httprequestHost=line.substring(6);System.out.println("Host \""+httprequestHost+"\"");}
                   if(line.length()==0){System.out.println("empty line");break;}
 
               }
 
               httpfullrequest = "\r\n" + httpfullrequest.trim() + "\r\n\r\n";
             //  request.close();
           } catch (IOException e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
           }
          busy=false;
       }
 
     public boolean isBusy() {
         return busy;
     }
 
     public String getFullRequest() {
         return httpfullrequest;
     }
 
 
     public String getRequestURL() {
         return httprequestURL;
     }
 
 
 
     public String getRequestHost() {
         return httprequestHost;
     }
     //@Override
     public String toString() {
         return "Request\n==============================\n" +httpfullrequest ;
 
     }
 
     }//http request class

Originally Posted by Norm

Do you have a driver class for executing and testing the program?

The server class Is the driver class.It has a main

Originally Posted by Norm

What are the steps for testing the code?

Set the proxy to server 8088 in your web browser .Then run the code and type in any url