java - Client-server application file transfer -

i trying design client-server application, this: user connects server , when authentication ok server send user files. problem files written in single file (with method).

here code:

the function transfers file

public void processfile(int id, dataoutputstream ostream, socket socket, int tip){         string filename;         if(tip==0){             filename="file"+integer.tostring(intrebari[id])+".txt";         }else{             filename="image"+integer.tostring(intrebari[id])+".jpg";         }         byte[] buffer=null;         int bytesread = 0;         fileinputstream file=null;          try {             file = new fileinputstream(filename);             buffer = new byte[socket.getsendbuffersize()];             while((bytesread = file.read(buffer))>0)                 {                 ostream.write(buffer,0,bytesread);                 }             file.close();         } catch (ioexception ex) {            system.out.println(ex);         }      } 

and function choose file have send

private void send(int id) throws ioexception {         os.writebytes("sendfile" + id+"\n");          system.out.println("sendfile" + id);         generatedfiles.processfile(id, os, comunicare, 0);         if (generatedfiles.imagini[id] == 1) {             os.writebytes("sendimage" + id+"\n");             try {                 thread.sleep(1000);             } catch (interruptedexception ex) {                 logger.getlogger(clientthread.class.getname()).log(level.severe, null, ex);             }             system.out.println("sendimage" + id);             generatedfiles.processfile(id, os, comunicare, 1);         }     } 

i have mention os dataoutputstream , comunicare socket type.

i think problem combine writebytes write. can me problem? how can make server , client receive both files , messages?

i this:

server -send command server -send file client -confirms file sucessfull

server -send command server -send file client -confirms file sucessfull ...

like this...supose have socket client, you...

socket.getoutputstream.write("file: somefile.bin, size: 872973493\r\n".getbytes("choose encoding")) socket.getoutputstream.flush(); (you need flush if expecting server string response like: ok send me file, im ready, otherwise no need too) client reads , see file , has bytes size, starts reading socket.getinputstream untill gets length of file expected. after clients confirm recived file

then server can send file, instead of file, use image: or want. have read message client side see if file or image

here functions might you:

public static void readinputstreamtofile(inputstream is, fileoutputstream fout,         long size, int buffersize) throws exception {     byte[] buffer = new byte[buffersize];     long curread = 0;     long totalread = 0;     long sizetoread = size;     while(totalread < sizetoread)     {         if(totalread + buffer.length <= sizetoread)         {             curread = is.read(buffer);         }         else         {             curread = is.read(buffer, 0, (int)(sizetoread - totalread));         }         totalread = totalread + curread;         fout.write(buffer, 0, (int) curread);     } }   public static void writefileinputstreamtooutputstream(fileinputstream in, outputstream out, int buffersize) throws exception {     byte[] buffer = new byte[buffersize];     int count = 0;     while((count = in.read(buffer)) != -1)     {         out.write(buffer, 0, count);     } }