Transfer a file via Socket

A client module connects to a server then a file is sent to the client. This exemple is very simple with no authentication and hard-coded filename!

First a server module.


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

public class FileServer {
public static void main (String [] args ) throws IOException {
// create socket
ServerSocket servsock = new ServerSocket(13267);
while (true) {
System.out.println("Waiting...");

Socket sock = servsock.accept();
System.out.println("Accepted connection : " + sock);

// sendfile
File myFile = new File ("source.pdf");
byte [] mybytearray = new byte [(int)myFile.length()];
FileInputStream fis = new FileInputStream(myFile);
BufferedInputStream bis = new BufferedInputStream(fis);
bis.read(mybytearray,0,mybytearray.length);
OutputStream os = sock.getOutputStream();
System.out.println("Sending...");
os.write(mybytearray,0,mybytearray.length);
os.flush();
sock.close();
}
}
}

The client module


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

public class FileClient{
public static void main (String [] args ) throws IOException {
int filesize=6022386; // filesize temporary hardcoded

long start = System.currentTimeMillis();
int bytesRead;
int current = 0;
// localhost for testing
Socket sock = new Socket("127.0.0.1",13267);
System.out.println("Connecting...");

// receive file
byte [] mybytearray = new byte [filesize];
InputStream is = sock.getInputStream();
FileOutputStream fos = new FileOutputStream("source-copy.pdf");
BufferedOutputStream bos = new BufferedOutputStream(fos);
bytesRead = is.read(mybytearray,0,mybytearray.length);
current = bytesRead;

// thanks to A. Cádiz for the bug fix
do {
bytesRead =
is.read(mybytearray, current, (mybytearray.length-current));
if(bytesRead >= 0) current += bytesRead;
} while(bytesRead > -1);

bos.write(mybytearray, 0 , current);
bos.flush();
long end = System.currentTimeMillis();
System.out.println(end-start);
bos.close();
sock.close();
}
}

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