//类一:
try {
     ObjectInputStream ois = new ObjectInputStream(socket.getInputStream());
     reception = ois.readObject();
     ois.close();
     socket.close(); //关闭Socket
} catch (Exception e) {
     e.printStackTrace();
}

//类二:
public Object reqInfo (Object req , Socket socket){
     ArrayList al = (ArrayList) req;
     al.add(socket);
     Object obj = (Object) al;
     return obj;
}

//类三:
public void jud_do(Object temp){
al = (ArrayList)temp;
sokect = al.get(X).toString();//X代表类二中socket存的位置
receiveRequest(socket)
}
  
//类四:
public void receiveRequest(Socket socket) {
        this.socket = socket; 
        try {
            ObjectOutputStream oos= new ObjectOutputStream(socket.getOutputStream());
            oos.writeObject(reception);
            oos.flush();
            oos.close();
            socket.close(); //关闭Socket
        } catch (Exception e) {
            e.printStackTrace();
        }
}