01 Networking

  public class CloseTestClient {

	public static void main(String[] args) throws Exception {
		final String msg = "This is line %3d of a long message " +
				"sent over TCP/IP to the server.\n";
		final int n = 400;

		String host = "localhost";
		int port = 1234;
		if (args.length > 0) { host = args[0]; }
		if (args.length > 1) { port = Integer.parseInt(args[1]); }
		
		Socket s = new Socket(host, port);
		System.out.println("sending data to " + s);

		OutputStream out = s.getOutputStream();

		// class Formatter formats data to a given out stream
		try (Formatter formatter = new Formatter(out)) {
			for (int i = 0; i < n; i++) {
				formatter.format(msg, i);
			}
			s.close();
			System.out.println("done.");
		}
	}
}
  

  public class CompressClient {

	public static final int BUFSIZE = 256; // Size of read buffer
	public static final String FILE_NAME = "Test"; // name of the generated file
	public static final int FILE_SIZE = 3200; // size of the generated file in KBtyes

	public static void main(String[] args) throws Exception {
		String server = "localhost";
		int port = 1234;
		// server = "86.119.38.130";
		// create a file with a given size
		createFile(FILE_NAME, FILE_SIZE * 1024);
		
		// Open input and output file (named input.gz)
		final FileInputStream fileIn = new FileInputStream(FILE_NAME);
		final FileOutputStream fileOut = new FileOutputStream(FILE_NAME + ".gz");

		// Create socket connected to server on specified port
		final Socket sock = new Socket(server, port);
		
		// Send uncompressed byte stream to server
		sendBytes(sock, fileIn);

		// Receive compressed byte stream from server
		InputStream sockIn = sock.getInputStream();
		int bytesRead;
		byte[] buffer = new byte[BUFSIZE]; 
		while ((bytesRead = sockIn.read(buffer)) != -1) {
			fileOut.write(buffer, 0, bytesRead);
			Log('R'); // Reading progress indicator
		}
		System.out.println(); // End progress indicator line

		sock.close();
		fileIn.close();
		fileOut.close();
	}

	private static void createFile(String name, int size) throws Exception {
		Random r = new Random();
		OutputStream out = new FileOutputStream(new File(name));
		byte[] buf = new byte[8];
		int pos = 0;
		while(pos < size) {
			Arrays.fill(buf, (byte)r.nextInt());
			out.write(buf, 0, Math.min(8, size-pos));
			pos += 8;
		}
		out.close();
	}

	private static void sendBytes(Socket sock, InputStream fileIn)
			throws IOException {
		OutputStream sockOut = sock.getOutputStream();
		int bytesRead;
		byte[] buffer = new byte[BUFSIZE];
		while ((bytesRead = fileIn.read(buffer)) != -1) {
			sockOut.write(buffer, 0, bytesRead);
			Log('W'); // Writing progress indicator
		}
		sock.shutdownOutput();
		System.out.println(); // End progress indicator line
	}

	private static int c = 0;
	static synchronized void Log(char s) {
		System.out.print(s);
		if(++c % 100 == 0) System.out.println();
	}
}