/* <!-- in case someone opens this in a browser... --> <pre> */
/*
 * This is a program that listens for HTTP requests on a given port
 * and sends back the HTTP header and body that were sent by the
 * client. It's nice for looking at the header information that your
 * browser is sending, or looking at the contents of SOAP requests
 * that a program is generating. It's just a little single-threaded 
 * job, so don't pretend it's a real web server or anything.
 *
 * Julian Robichaux -- http://www.nsftools.com
 */
import java.io.*;
import java.net.*;

public class HttpEcho
{
	public static void main (String args[])
	{
		if (args.length == 0)
		{
			System.out.println("USAGE: java HttpEcho <port number>");
			return;
		}
			
		
		try {
			int port = Integer.parseInt(args[0]);
			ServerSocket server = new ServerSocket(port);
			System.out.println("Started HttpEcho on port " + port + ". Press CTRL-C to end.\n");
			
			while (true)
			{
				Socket client = server.accept();
				BufferedReader in = new BufferedReader(
									new InputStreamReader(client.getInputStream()));
				PrintWriter out = new PrintWriter(client.getOutputStream());
				
				StringBuffer header = new StringBuffer("");
				StringBuffer body = new StringBuffer("");
				String data;
				int contentLength = 0;
				int pos = 0;
				
				// get the header
				while ((data = in.readLine()) != null)
				{
					// the header ends at the first blank line
					if (data.length() == 0)
						break;
					header.append(data + "\n");
					pos = data.toLowerCase().indexOf("content-length:");
					if (pos >= 0)
						contentLength = Integer.parseInt(data.substring(pos + 15).trim());
				}
				
				// get the body, if any
				if (contentLength > 0)
				{
					try {
						char[] cbuf = new char[contentLength];
						in.read(cbuf);
						body.append(cbuf);
					}  catch (Exception e)  {
						body.append("Error: " + e);
					}
				}  else  {
					body.append("No Body information retrieved. " + 
								"Content-Length equals zero or was not specified.");
				}
				
				// write back to the client
				out.print("HTTP/1.0 200\nContent Type: text/plain\n\n");
				out.println("HEADER:");
				out.println(header);
				out.println("BODY:");
				out.println(body);
				
				// write to the console too
				System.out.println("HEADER:");
				System.out.println(header);
				System.out.println("BODY: (" + contentLength + " / " + body.length() + ")");
				System.out.println(body);
				System.out.println("\n============ HttpEcho on Port " + port + 
									". Press CTRL-C to End ============\n");
				
				// close all the client streams so we can listen again
				out.close();
				in.close();
				client.close();
			}
		}  catch (Exception e)  {
			System.out.println(e);
		}
	}
}