客户与服务器之文件传送

服务器
import java.io.*;
import java.net.*;
public class Server implements Runnable{
private Socket socket;
private int ID;
Server(Socket socket,int ID){
this.socket=socket;
this.ID=ID;
}
public static void main(String[] args){

int port=9999;
int count=0;
try{
ServerSocket s=new ServerSocket(port);
System.out.println(" 正在等待端口 "+port);
while(true){
Socket socket=s.accept();
System.out.println("第"+ ++count+"台电脑已经获得连接！！！");
Server server=new Server(socket,count);
Thread thread=new Thread(server);
thread.start();
}
}
catch(Exception e){
System.out.print("错误！！");
}
}

public void run(){
try{

InputStream is=socket.getInputStream();
InputStreamReader isr=new InputStreamReader(is);
BufferedReader br=new BufferedReader(isr);

FileOutputStream fos=new FileOutputStream(new File("aa.txt"));
String str=br.readLine();
byte[] b=new byte[1024];
b=str.getBytes();
fos.write(b);
}
catch(Exception e){
System.out.println(e.toString());
}

finally{
try{
socket.close();
System.out.println(ID+"已经断开了！！！");
}
catch(Exception e){
System.out.print("最后有错误！！");
}
}
}
}
*********************
客户
import java.io.*;
import java.net.*;
public class Client{
public static void main(String[] args){
int port=9999;

try{
InetAddress address=InetAddress.getByName("192.168.0.1");
Socket socket=new Socket(address,port);
String file=args[0];
FileInputStream fips=new FileInputStream(file);
BufferedInputStream bis=new BufferedInputStream(fips);
DataInputStream in=new DataInputStream(bis);

BufferedReader br=new BufferedReader(new InputStreamReader(in));





OutputStream os=socket.getOutputStream();
OutputStreamWriter osw=new OutputStreamWriter(os);
PrintWriter pw=new PrintWriter(osw);

pw.print(br.readLine());
pw.flush();



}
catch(Exception e){
System.out.println(e.toString());
}
}
}
############
我想请教一下，我的目的是用Client这个程序，将一个文件通过网络，发送到Server这个程序上，然后由Server这个程序把数据写到一个自命名的文件上。
请高手指教!!!谢谢!!