public class HttpClient2 {
    public static void main(String[] args) {
        try {
            // Check the arguments
            if ((args.length != 1) && (args.length != 2))
                throw new IllegalArgumentException("Wrong number of args");
            
            // Get an output stream to write the URL contents to
            OutputStream to_file;
            if (args.length == 2) to_file = new FileOutputStream(args[1]);
            else to_file = System.out;
            
            // Now use the URL class to parse the user-specified URL into
            // its various parts.  
            URL url = new URL(args[0]);
            String protocol = url.getProtocol();
            if (!protocol.equals("http")) // Check that we support the protocol
               throw new IllegalArgumentException("Must use 'http:' protocol");
            String host = url.getHost();
            int port = url.getPort();
            if (port == -1) port = 80; // if no port, use the default HTTP port
            String filename = url.getFile();
 
            // Open a network socket connection to the specified host and port
            Socket socket = new Socket(host, port);
 
          
             // Get input and output streams for the socket (modified inspired in HTTPMirror)
                BufferedReader in = 
                	new BufferedReader(
			       		new InputStreamReader(
			       			socket.getInputStream()));
			       			
                PrintWriter out = new PrintWriter(socket.getOutputStream());
 
                // Send the HTTP GET command to the Web server, specifying the file
                // This uses a newer version from the HTTP protocol.
                
                out.print("GET " + filename + "\n"); 
                out.write(filename);    
                out.print("\n");                         // End 
                out.flush(); // Send it right now!
 
                // 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;
                // this is the header reader
                while((line = in.readLine()) != null) {
                    if (line.length() == 0) break;
                    System.out.println(line + "\n");
                }
                
                // this is the GET reader
                while((line = in.readLine()) != null) {
                    if (line.length() == 0) break;
                    System.out.println(line + "\n");
                }
 
            
		
		socket.close();		// Close the socket itself
 
		in.close();      // Close the input stream
		to_file.close();     // Flush and close the output stream 
        }
        catch (Exception e) {    // Report any errors that arise
            System.err.println(e);
            System.err.println("Usage: java HttpClient2 <URL> [<filename>]");
        }
    }
}

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

public class HttpClient2 {
    public static void main(String[] args) {
	    Socket socket = null;
        try {
            // Check the arguments
            if ((args.length != 1) && (args.length != 2))
                throw new IllegalArgumentException("Wrong number of args");
           
            // Get an output stream to write the URL contents to
            FileWriter fw = new FileWriter(args[1]);
           
            // Now use the URL class to parse the user-specified URL into
            // its various parts. 
            URL url = new URL(args[0]);
            String protocol = url.getProtocol();
            if (!protocol.equals("http")) // Check that we support the protocol
               throw new IllegalArgumentException("Must use 'http:' protocol");
			String html = "";
			String resource = "/";
			String headerString = "";
			String host = url.getHost();
			int httpPort = 80;
			String userAgent = "";
			System.out.println("Creating connection to " + host 
				  + " on port " + String.valueOf(httpPort) + ".");
			socket = new Socket(host, httpPort);
			//create connection
			System.out.println("Created socket: " + socket.toString());

			System.out.println("Setting up communications to and from the connection.");
			PrintStream ps = new PrintStream(socket.getOutputStream());

			String request = "TRACE " + resource + "  HTTP/1.0\n";
		  	request = request + "Hello: hey over there\n";
			request = request +  "User-Agent: Java Man From Mars\n";
			request = request + "Host: host\n";
			request = request + "Accept: text/html, image/gif, image/jpeg, /\n";
			request = request + "Connection: close\n";

			System.out.println("Sending HTTP request: " + request);
			ps.println(request);
			ps.flush();
			BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
			System.out.println("Reading webpage header: " + host + resource);
			//read up to blank line
			String s = br.readLine();
			fw.write(s + "\n");

			while ((s = br.readLine()) != null && !s.equals("")){
				headerString = headerString + s;
				s = br.readLine();
				System.out.println(s);
				fw.write(s + "\n");
				if (s.indexOf("User-Agent") >= 0){
					System.out.println("Found User-Agent");
					userAgent = s.substring(s.indexOf(":") + 1);
					System.out.println("User-Agent: " + userAgent);					
				}
			}
			System.out.println("Reading webpage: " + host + resource);

			s = br.readLine();
				fw.write(s + "\n");
			while((s = br.readLine()) != null){
				html = html + s + "\n";
				System.out.println(s);
				fw.write(s + "\n");
				if (s.indexOf("User-Agent") >= 0){
					System.out.println("Found User-Agent");
					userAgent = s.substring(s.indexOf(":") + 1);
					System.out.println("User-Agent: " + userAgent);					
				}
			}
			fw.close();
		}catch(MalformedURLException murle){
			System.err.println("MalformedURLException: " + murle.getMessage());
		}catch(UnknownHostException uhe){
			System.err.println("UnknownHostException: " + uhe.getMessage());
		}catch (ConnectException ce){
			System.err.println("ConnectException: " + ce.getMessage());
		}catch (IOException ioe){
			System.err.println("IOException: " + ioe.getMessage());
		}finally{
			if (socket != null) {
				try{
					socket.close();
				}catch (IOException ioe){
					System.err.println("IOException: " + ioe.getMessage());
				}
			}
		}
    }
}