socket server端无法捕获异常：recvfrom fail :ETIMEDOUT

Question

A手机：开wifi热点，做socket server端
B手机：做socket client端，连接A手机的socket server
socket连接建立后，两边都调用读阻塞；
关闭A手机热点或关闭B手机wifi：client端能捕获异常 recvfrom fail :ETIMEDOUT，server无法捕获请问这是什么原因，有没有办法让server端也捕获到异常？socket

Answer 1

服务端代码：
                Thread a = new Thread() {
                    public void run() {
                        ServerSocket socket;
                        try {
                            socket = new ServerSocket(40000);
                            Socket client = socket.accept();
                            if (null != client) {
                                InputStream in = client.getInputStream();
                                BufferedReader reader = new BufferedReader(
                                        new InputStreamReader(in));
                                reader.readLine();
                            }
                        } catch (IOException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                    }
                };
                a.start();客户端代码：
                Thread a = new Thread() {
                    public void run() {
                        try {
                            Socket server = new Socket();
                            SocketAddress socketAddress = new InetSocketAddress("192.168.43.1",
                                    40000);
                            server.connect(socketAddress);
                            InputStream in = server.getInputStream();
                            BufferedReader reader = new BufferedReader(new InputStreamReader(in));
                            reader.readLine();
                        } catch (IOException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                    }
                };
                a.start();

Answer 2

刚试了把开热点的机器作为客户端，这种情况下断网，socket 服务端可以捕获异常recvfrom fail :ETIMEDOUT现在问题比较明确了，是作为热点的一端无法捕获此异常，有人知道原因吗，请回一下，在线等，谢谢