Question

我正在制作一个客户端服务器。我的客户端很好地连接到服务器，它在套接字上创建ObjectInputStream（socket.getInputStream（）），从服务器到客户端，反之亦然。然后出于一些神秘的原因，我的服务器的ObjectInputStream以某种方式捕获一个空对象。客户端没有通过套接字发送任何东西（我确实把/../放在了对象发送方法上，以确保这一点，甚至System.out.printed所有先前发送的对象）服务器捕获了神秘对象只有一次，之后客户端发送的所有对象都按照它们的方式工作..

class ClientThread extends Thread {
        //The socket where to listen/talk
        Socket socket;
        ObjectInputStream sInput;
        ObjectOutputStream sOutput;
        InputStream fInput;
        OutputStream Output;
        //my unique id (easier for deconnection)
        int id;
        //Objects that we will be receiving
        Incomingdata datain;
        //the date we connect
        String date;
        Player player;
        boolean Connected = false;

        //Constructor
        ClientThread(Socket socket){
            id = uniqueId++;
            this.socket = socket;
            try{
                sOutput = new ObjectOutputStream(socket.getOutputStream());
                sInput = new ObjectInputStream(socket.getInputStream());
                Output = socket.getOutputStream();
            } catch (Exception e){
                System.out.println("Couldn't create Input/Output streams");
            }
            date = new Date().toString();
        }

        // what will run forever
        public void run() {
            // to loop until LOGOUT
            Connected = true;
            while(Connected) {
                try {
                    datain = (Incomingdata) sInput.readObject(); //<--- this catches the mystical null! Even if nothing is sent over the socket?
                }
                catch (IOException e) {
                    TextArea.AddLine("Exception reading Streams: " + e);
                    break;              
                }
                catch(ClassNotFoundException e2) {
                    break;
                }

Answer 1

如果发送空值，则只能收到空值。

（人们普遍存在一种误解，即readObject()在流的末尾返回null。它没有。）

Java ObjectInputStream（socket.getInputStream（））捕获null对象

1 个答案: