我想从我的客户机发送一个字符串列表到服务器。
服务器

ObjectOutputStream objectOutput = new ObjectOutputStream(connsock.getOutputStream());
public  List<String> current_clients_listening_songs = new ArrayList<String>();

current_clients_listening_songs.add("client 1 is listening to" + song);//song variable is string
//send list to client
objectOutput.writeObject(current_clients_listening_songs);

客户

ObjectInputStream objectInput = new ObjectInputStream(clientSocket.getInputStream());

//get list from server
Object get_client_listening = objectInput.readObject();

ArrayList<String> client_listening_songs = new ArrayList<String>();
//make a new list with server's list data
client_listening_songs = (ArrayList<String>) get_client_listening;
//print data
for (int i = 0; i < client_listening_songs.size(); i++) {

    System.out.println(client_listening_songs.get(i));
    }

服务器确实在列表中添加了项，但是客户端没有得到它们，怎么了？