/* * Copyright (c) 2000 David Flanagan.  All rights reserved. * This code is from the book Java Examples in a Nutshell, 2nd Edition. * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied. * You may study, use, and modify it for any non-commercial purpose. * You may distribute it non-commercially as long as you retain this notice. * For a commercial use license, or to purchase the book (recommended), * visit http://www.davidflanagan.com/javaexamples2. */package com.davidflanagan.examples.net;import java.io.*;import java.net.*;/** * This program is a very simple Web server.  When it receives a HTTP request * it sends the request back as the reply.  This can be of interest when * you want to see just what a Web client is requesting, or what data is * being sent when a form is submitted, for example. **/public class HttpMirror {    public static void main(String args[]) {        try {            // Get the port to listen on            int port = Integer.parseInt(args[0]);            // Create a ServerSocket to listen on that port.            ServerSocket ss = new ServerSocket(port);            // Now enter an infinite loop, waiting for & handling connections.            for(;;) {                // Wait for a client to connect.  The method will block;		// when it returns the socket will be connected to the client                Socket client = ss.accept();                // Get input and output streams to talk to the client                 BufferedReader in = new BufferedReader(			       new InputStreamReader(client.getInputStream()));                PrintWriter out = new PrintWriter(client.getOutputStream());                // Start sending our reply, using the HTTP 1.0 protocol                out.print("HTTP/1.0 200 \n");          // Version & status code                out.print("Content-Type: text/plain\n"); // The type of data                out.print("\n");                         // End of headers                // Now, read the HTTP request from the client, and send it                // right back to the client as part of the body of our                // response.  The client doesn't disconnect, so we never get                // an EOF.  It does sends an empty line at the end of the                // headers, though.  So when we see the empty line, we stop                // reading.  This means we don't mirror the contents of POST                // requests, for example.  Note that the readLine() method 		// works with Unix, Windows, and Mac line terminators.                String line;                while((line = in.readLine()) != null) {                    if (line.length() == 0) break;                    out.print(line + "\n");                }                // Close socket, breaking the connection to the client, and		// closing the input and output streams		out.close();     // Flush and close the output stream		in.close();      // Close the input stream                client.close();  // Close the socket itself            } // Now loop again, waiting for the next connection        }        // If anything goes wrong, print an error message        catch (Exception e) {            System.err.println(e);            System.err.println("Usage: java HttpMirror <port>");        }    }}