Sockets and InputStream

[sani]

Hi

I want to move files (ascii and binarys) between two systems and have to use sockets for that. Now, I wrote this simple program (for test only):

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

public class Server
{

    public static void main(String[] args) throws IOException
    {
        String fileName = "note.txt";

        ServerSocket server = new ServerSocket(8080);
        FileInputStream fis = new FileInputStream(fileName);

        System.out.println("\nServer is ready: 8080\n");
       
        Socket client = server.accept();

        InputStream socketInput = client.getInputStream();
        OutputStream socketOutput = client.getOutputStream();
       
   
        // wait for ok (if n == 0)
        int n = socketInput.read();

        if (n == 0)
        {
            byte[] buffer = new byte[10];

            int count = 0;

            count = fis.read(buffer);

            while (count != -1)
            {
                // send data
                socketOutput.write(buffer);
                // read data from file again
                count = fis.read(buffer);
            }
        }

        // only to avoid closing of the 'socketOutput'
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter an int-number: ");
        sc.nextInt();
       
        socketOutput.close();
    }
}

And the client-class:

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

public class Client
{

    public static void main(String[] args) throws UnknownHostException,
            IOException
    {
        FileOutputStream fos = new FileOutputStream("C:/Temp/client/fileCopied.txt");

        Socket client = new Socket("127.0.0.1", 8080);

        OutputStream socketOutput = client.getOutputStream();
        InputStream socketInput = client.getInputStream();

        int n = 0;

        // send OK
        socketOutput.write(n);

        byte[] buffer = new byte[10];

        int count = 0;

        // read data
        count = socketInput.read(buffer);

        while (count != -1)
        {
            // write data into file
            fos.write(buffer);
            // read data from socket-InputStream again
            count = socketInput.read(buffer);  // here waits the client for new data!!!
        }

        fos.close();

        // only for debug
        Scanner sc = new Scanner(System.in);
        System.out.print("enter an int-number: ");
        int x = sc.nextInt();
    }
}

And now my problem:
The client is not able to recognize the end of the stream (-1). If I close the Server-OutputStream, the client is go on. Otherwise the client waits for new data to read. What I'm doing wrong? And, how to say the client, that the there are no more data, without closing the Server-OutputStream?

Tahnks for any help and HAPPY NEW YEAHR.

 

[Grizzly]

On the start of the transmission, send the length of bytes of the file as an long. So the client knows the size of the file / the length of the transmission.

Happy New Year, too.

 

[SlaterB]

else you could send a special char-sequence to indicate a special situation,

else there is nothing to do, you can only send data or close the stream

-------

hint:

if the Server reads at the end of a file the last 5 chars,
the byte-Array has the 5 new chars at postion 0-4 and 5 old ones at position 5-9 which you are sending the client,
the client cannot distinguish between old an new chars and writes all in the file!

->

while (count != -1) {
	// send data
	socketOutput.write(buffer,0,count);
	// read data from file again
	count = fis.read(buffer);
}


while (count != -1) {

	// write data into file
	fos.write(buffer,0,count);
				
	// read data from socket-InputStream again
   count = socketInput.read(buffer);
}