Fetching a URL from a socket output or input stream in a proxy server

Question

We have written a proxy server in java .
It connects with a client on some local port and forwards the request of the client to main server through socket connections.
The code is as follows...
* BasicProxyServer.java
* A simple multithreaded proxy server.
* A client connects to theserver. The server starts a
* separate threads for data flow though two Sockets.
* The first socket communicates with the socket of the client.
* The second socket is used to communcate with the main server
* for which this server is a proxy. The sockets are connected by pipes.
import java.net.*;
import java.io.*;
public class BasicProxyServer {
     private static int serverPort;
     private static String primaryServerHost;
     private static int primaryServerPort;
     // 1st arg: port to listen on
     // 2nd arg: primary server IP
     // 3rd arg: primary server port
     public static void main(String [] args) {
          serverPort = Integer.parseInt(args[0]);
          primaryServerHost = args[1];
          primaryServerPort = Integer.parseInt(args[2]);
          BasicServer bserv = new BasicServer(serverPort,primaryServerHost,primaryServerPort);
class BasicServer extends Thread {
     private int serverPort;
     private String primaryHost;
     private int primaryPort;
     private ServerSocket servSock = null;
     public BasicServer(int port, String primSrv, int primPort) {
          serverPort = port;
          primaryHost = primSrv;
          primaryPort = primPort;
          start();
     public void run() {
          Socket clientSock = null;
          Socket primaryServerSock = null;
          try {
               servSock = new ServerSocket(serverPort);
          catch (IOException e) {
               e.printStackTrace();
          while(true) {
               try {
                    clientSock = servSock.accept();
                    primaryServerSock = new Socket(primaryHost, primaryPort);
                    PipedInputStream fromClient = new PipedInputStream();
                    PipedOutputStream toMainServer = new PipedOutputStream(fromClient);
                    PipedInputStream fromMainServer = new PipedInputStream();
                    PipedOutputStream toClient = new PipedOutputStream(fromMainServer);
                    Talk clientToMainServer = new Talk(clientSock, fromClient, primaryServerSock, toMainServer);
                    Talk mainServerToClient = new Talk(primaryServerSock, fromMainServer, clientSock, toClient);
                    clientToMainServer.start();
                    mainServerToClient.start();
               catch (IOException e) {
                    e.printStackTrace();
     // Override finalize() to close server socket
protected void finalize() {
if (servSock != null) {
try {
servSock.close();
} catch (IOException e) {
e.printStackTrace();
servSock = null;
class Talk extends Thread {
     private Socket incoming;
     private Socket outgoing;
     private InputStream in;
     private OutputStream out;
     private InputStream from;
     private OutputStream to;
     Talk(Socket inSock, InputStream in, Socket outSock, OutputStream out) {
          this.in = in;
          this.out = out;
          incoming = inSock;
          outgoing = outSock;
     public void run() {
          int aByte;
          try {
               from = incoming.getInputStream();
               to = outgoing.getOutputStream();          
               while(( aByte = from.read()) != -1 ) {     //read from socket
                    out.write(aByte);     // write to pipe`
                    // read the byte from the pipe
                    to.write(in.read());          // write it to the output socket stream
                    to.flush();
               to.close();
               from.close();
               if(incoming != null) {
                    incoming.close();
                    incoming = null;
               if(outgoing != null) {
                    outgoing.close();
                    outgoing = null;
          catch (SocketException e) {
          // there is one for a closed socket. Seems to have no effect.
          //     e.printStackTrace();
          catch (IOException e) {
               e.printStackTrace();
Here,when client gives any URL in the address bar in the web browser the request is forwarded to this proxy server.
We want to fetch the URL which client enters in order to implement content filtering and also store the most visited sites by each user .
But we don't know how to fetch the URL from the socket input or output stream.
Can you suggest any suitable solution for the same??

Answer 1

Shailesh24 wrote:
We want to fetch the URL which client enters in order to implement content filtering and also store the most visited sites by each user .
But we don't know how to fetch the URL from the socket input or output stream.
Can you suggest any suitable solution for the same??Yes. Write a proxy server that actually speaks HTTP.