import java.net.*;
import java.io.*; 
import java.util.*; 

public class TinyHttpd {

  public static void main( String argv[] ) throws IOException {

    // Get the port number from the command line
    // Create a ServerSocket object to watch 
    // this port for clients
    ServerSocket ss =
       new ServerSocket( Integer.parseInt(argv[0]));
    System.out.println("starting...");

    // Here we loop indefinitely, just waiting for 
    // clients to connect
    while ( true ) {

      // accept() does not return until a client 
      // requests a connection.
	 // Now that a client has arrived, create an instance 
      // of our special thread subclass to respond to it. 
      new TinyHttpdConnection( ss.accept() ).start(); 
      System.out.println("new connection"); 
  
    } // Now loop back around and wait 
      // for next client to be accepted. 
  } 
} 

// Here is our thread class to handle clients.
class TinyHttpdConnection extends Thread { 
  Socket client; 

  // Pass the socket as a argument to the constructor
  TinyHttpdConnection ( Socket client ) throws SocketException { 
    this.client = client; 

    // Set the thread priority down so that the ServerSocket
    // will be responsive to new clients.
    setPriority( NORM_PRIORITY - 1 ); 
  } 

  public void run() { 
    try { 

      // Use the client socket to obtain an input stream from it.
      // For text input we wrap an InputStreamReader around 
      // the raw input stream and set ASCII character encoding. 
      // Finally, use a BufferReader wrapper to obtain 
      // buffering and higher order read methods.
      BufferedReader in = new BufferedReader(
	new InputStreamReader(client.getInputStream(),"8859_1"));

      // Now get an output stream to the client.
      OutputStream out = client.getOutputStream(); 

      // For text output we wrap an OutputStreamWriter around 
      // the raw output stream and set ASCII character encoding.
      // Finally, we use a PrintWriter wrapper to obtain its
      // higher level output methods.
      // Open in append mode. 
      PrintWriter pout = new PrintWriter(
	new OutputStreamWriter(out, "8859_1"), true ); 

      // First read the request line from the client
      String request = in.readLine(); 
      System.out.println( "Request: "+request ); 

      // Use aStringTokenizer to examine the request text.
      StringTokenizer st = new StringTokenizer( request ); 

      // Check if HTTP/1.0 or later. If so, add MIME header 
      boolean sendMIME = false; 
      if ( request.indexOf("HTTP/") != -1) sendMIME = true; 

      // Check that the request has a minimun number of words
      // and that the first word is the GET command.
      if ( (st.countTokens() >= 2) &&
	    st.nextToken().equals("GET") ) { 

	// Ignore the leading "/" on the file name.
	if ( (request = st.nextToken()).startsWith("/") ) 
	  request = request.substring( 1 ); 

	// If no file name is there, use index.html default.

	if ( request.endsWith("/") || request.equals("") ) 
	  request = request + "index.html"; 

	// Check if the file is hypertext or plain text 
	String ContentType; 
	if (request.endsWith(".html") || 
	    request.endsWith(".htm")) { 
	   ContentType = "text/html"; 
	} 
	else { 
	   ContentType = "text/plain"; 
	} 

	// Now read the file from the disk and write it to the
	// output stream to the client.
	try { 

	  // Open a stream to the file. Remember that by this
	  // all the text but the file name has been stripped 
	  // from the "request" string. 
	  FileInputStream fis = new FileInputStream ( request ); 

	  if( sendMIME) { 
	    // Follow example in "Java Network Programming"
	    PrintStream os = new PrintStream(out); 
	    os.print("HTTP/1.0 200 OK\r\n"); 
	    Date now = new Date(); 
	    os.print("Date: " + now + "\r\n"); 
	    os.print("Server: TinyHttpd 1.0\r\n"); 
	    os.print("Content-length: " + fis.available() +
		     "\r\n"); 
	    os.print("Content-type: " + ContentType + 
		     "\r\n\r\n"); 
	  } 

	  // Creat a byte array to hold the file.
	  byte [] data = new byte [ fis.available() ]; 

	  fis.read( data ); // Read file into the byte array
	  out.write( data );// Write it to client output stream
	  out.flush();      // Remember to flush output buffer

	} catch ( FileNotFoundException e ) { 
	  // If no such file, then send the famous 404 message.
	  pout.println( "404 Object Not Found" ); } 

      } else 
	pout.println( "400 Bad Request" ); 
      client.close(); 
    } catch ( IOException e ) { 
      System.out.println( "I/O error " + e ); } 
  // On return from run() the thread process will stop. 
  } 
}