Java Try-With-Resources 未知资源计数

Question

我需要打开 N 个多播套接字(其中 N 来自参数列表的大小)。然后，我将在循环内将相同的数据发送到 N 个套接字中的每一个，最后关闭每个套接字。我的问题是，如何使用 try-with-resources block 来做到这一点？以下是我如何使用单个资源执行此操作:

final int port = ...;
try (final MulticastSocket socket = new MulticastSocket(port)) {
    // Do a bunch of sends of small packet data over a long period of time
    ...
}

我能想到的使用多个端口执行此操作的唯一方法如下:

final List<Integer> ports = ...;
final List<MulticastSocket> sockets = new ArrayList<>(ports.size());
try {
    for (final Integer port : ports) {
        sockets.add(new MulticastSocket(port));
    }

    // Do a bunch of sends of small packet data over a long period of time
    ...
} finally {
    for (final MulticastSocket socket : sockets) {
        try {
            socket.close();
        } catch (final Throwable t) {
            // Eat the exception
        }
    }
}

是否有更简洁的方法来完成此任务，或者我提出的解决方案是否足够好？

Answer 1

递归地执行以保持 try-with-resources 的保证:

void foo(List<Integer> ports, List<Socket> sockets) {
  if (sockets.size() == ports.size()) {
    // Do something with your sockets.
  } else {
    try (Socket s = new MulticastSocket(ports.get(sockets.size())) {
      sockets.add(s);
      foo(ports, sockets);
      // You could call sockets.remove(sockets.size()-1) here.
      // Not convinced whether it's worth it.
    }
  }
}