StoreThread.java

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

public class StoreThread implements Runnable{

    private final PrintWriter controller;
    private final String filePath;
    private final String fileName;
    private final InputStream in;
    private final OutputStream out;
    private final Socket client;
    private final int fileSize;

    public StoreThread(PrintWriter co, String p, String n, InputStream i, OutputStream o, Socket c, int fs) {
        controller = co;
        filePath = p;
        fileName = n;
        in = i;
        out = o;
        client = c;
        fileSize = fs;
    }

    @Override
    public void run() {
        try {
            //Send ACK to client
            out.write("ACK".getBytes());

            //Prepare to write to file
            File outputFile = new File(filePath+File.separator+fileName);
            FileOutputStream fileOutput = new FileOutputStream(outputFile);

            //Read correct bytes from input stream and write to file
            byte[] buf = in.readNBytes(fileSize);
            fileOutput.write(buf);

            //Send completion ack to controller
            controller.println("STORE_ACK "+fileName);
            controller.flush();

            //Close file output
            fileOutput.close();

            //Close streams
            in.close();
            out.close();
            client.close();
        }catch (Exception e){
            System.out.println("error "+e);
        }
    }
}