Connect.java Source code

Introduction

Here is the source code for Connect.java

Source

/*
 * Copyright (c) 2004 David Flanagan.  All rights reserved.
 * This code is from the book Java Examples in a Nutshell, 3nd 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,
 * including teaching and use in open-source projects.
 * You may distribute it non-commercially as long as you retain this notice.
 * For a commercial use license, or to purchase the book, 
 * please visit http://www.davidflanagan.com/javaexamples3.
 */
//package je3.net;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.SocketTimeoutException;

/**
 * A simple network client that establishes a network connection to a specified
 * port on a specified host, send an optional message across the connection,
 * reads the response from the server and exits. A suitable client for simple
 * network services like the daytime or finger.
 */
public class Connect {
    public static void main(String[] args) {
        try { // Handle exceptions below
            // Get our command-line arguments
            String hostname = args[0];
            int port = Integer.parseInt(args[1]);
            String message = "";
            if (args.length > 2)
                for (int i = 2; i < args.length; i++)
                    message += args[i] + " ";

            // Create a Socket connected to the specified host and port.
            Socket s = new Socket(hostname, port);

            // Get the socket output stream and wrap a PrintWriter around it
            PrintWriter out = new PrintWriter(s.getOutputStream());

            // Sent the specified message through the socket to the server.
            out.print(message + "\r\n");
            out.flush(); // Send it now.

            // Get an input stream from the socket and wrap a BufferedReader
            // around it, so we can read lines of text from the server.
            BufferedReader in = new BufferedReader(new InputStreamReader(s.getInputStream()));

            // Before we start reading the server's response tell the socket
            // that we don't want to wait more than 3 seconds
            s.setSoTimeout(3000);

            // Now read lines from the server until the server closes the
            // connection (and we get a null return indicating EOF) or until
            // the server is silent for 3 seconds.
            try {
                String line;
                while ((line = in.readLine()) != null)
                    // If we get a line
                    System.out.println(line); // print it out.
            } catch (SocketTimeoutException e) {
                // We end up here if readLine() times out.
                System.err.println("Timeout; no response from server.");
            }

            out.close(); // Close the output stream
            in.close(); // Close the input stream
            s.close(); // Close the socket
        } catch (IOException e) { // Handle IO and network exceptions here
            System.err.println(e);
        } catch (NumberFormatException e) { // Bad port number
            System.err.println("You must specify the port as a number");
        } catch (ArrayIndexOutOfBoundsException e) { // wrong # of args
            System.err.println("Usage: Connect <hostname> <port> message...");
        }
    }
}