HTTPClient

HTTPClient.java

// MyStreamSocket is a Java class presented in Chapter 4.
// import MyStreamSocket;
import java.net.*;
import java.io.*;

public class HTTPClient {

// An application which communicates with a HTTP
// server to retrieve the text contents of a web page.
// These command line arguments are expected, in order: 
//    <host name of the HTTP server>
//    <port number of the HTTP server>
//    <full path to a web document on the server host>

   public static void main(String[] args) {
      if (args.length != 3)
         System.out.println
            ("This program requires 3 command line arguments");
      else {
         try {
  		      InetAddress host = 
                InetAddress.getByName(args[0]);
  		      int port = Integer.parseInt(args[1]);
            String fileName = args[2].trim();
            String request = 
               "GET " + fileName + " HTTP/1.0\n\n";
         	MyStreamSocket mySocket = 
              new MyStreamSocket(host, port);                             
            /**/  System.out.println("Connection made");
            mySocket.sendMessage(request);
	         // now receive the response from the HTTP server
            String response;         
            response = mySocket.receiveMessage();
            // read and display one line at a time
            while (response != null) {
              System.out.println(response);
              response = mySocket.receiveMessage();
            }
         } // end try
         catch (Exception ex) {
            System.out.println("ERROR : " + ex) ;
	         ex.printStackTrace(System.out);
	      }  // end catch
      }// end else
   }// end main 
	
}
	class MyStreamSocket extends Socket {
		private Socket  socket;
		private BufferedReader input;
		private PrintWriter output;
		
		MyStreamSocket(InetAddress acceptorHost,
					   int acceptorPort ) throws SocketException,
		IOException{
			socket = new Socket(acceptorHost, acceptorPort );
			setStreams( );
			
		}
		
		MyStreamSocket(Socket socket)  throws IOException {
			this.socket = socket;
			setStreams( );
		}
		
		private void setStreams( ) throws IOException{
			// get an input stream for reading from the data socket
			InputStream inStream = socket.getInputStream();
			input = 
			new BufferedReader(new InputStreamReader(inStream));
			OutputStream outStream = socket.getOutputStream();
			// create a PrinterWriter object for character-mode output
			output = 
			new PrintWriter(new OutputStreamWriter(outStream));
		}
		
		public void sendMessage(String message)
		throws IOException {	
			output.print(message + "\n");   
			//The ensuing flush method call is necessary for the data to
			// be written to the socket data stream before the
			// socket is closed.
			output.flush();               
		} // end sendMessage
		
		public String receiveMessage( )
		throws IOException {	
			// read a line from the data stream
			String message = input.readLine( );  
			return message;
		} //end receiveMessage
		
		public void close( )
		throws IOException {	
			socket.close( );
		}
	} //end class