Reader i Writer prenose 16bit, Stream 8bit.
Dakle, koristi Stream za prenos fajlova.
Poslacu ti kasnije code, ako budem imao vremena, sad nemam.
Ali pokusaj sam da nadjes, tako se najbolje uci ;)

Elem rersio sam problem, al' je dosta sporo:
Server:
FileInputStream input=new FileInputStream("C:\\ivan.txt");
OutputStream output=sock.getOutputStream();
byte[] nextBytes=new byte[sock.getSendBufferSize()];
int bytesRead=0;
while((bytesRead=input.read(nextBytes))>0){
output.write(nextBytes,0,bytesRead);
}

Klijent:
FileOutputStream output=new FileOutputStream(novi);
byte [] outBuffer=new byte[sock.getReceiveBufferSize()];
System.out.println(outBuffer.length);
InputStream input=sock.getInputStream();
int byteReceived=0;
while ((byteReceived=input.read(outBuffer))>0){
output.write(outBuffer,0,byteReceived);
}
bitno je da velicina outBuffer bude manja od velicine fajla, u suprotnom ne radi...
Mana je sto je ova varijanta spora.
Jel zna neko dal' ovo moze da se izvede preko kanala soketa, i dal je brze...

Probaj da umesto Output/InputStream koristis BufferedOutput/InputStream.