如何使用WebSocket使UWP应用程序与Java服务器一起使用

Question

我正在尝试创建一个与Java服务器通信的UWP Websocket，但是当我尝试在java端获取输入流时，它会抛出NullPointerException，我应该如何配置UWP Websocket以使其与java服务器一起工作？如果你能告诉我怎么能从UWP发送一个对象并在java端解析它，谢谢你sooo muchhh :(：

Provider.java：

public class Server{
    ServerSocket providerSocket;
    Socket connection = null;
    ObjectOutputStream out;
    ObjectInputStream in;
    String message;
    MesageModel model;
    Provider(){}
    void run()
    {
        try{
            providerSocket = new ServerSocket(9999, 10);
            System.out.println("Waiting for connection");
            connection = providerSocket.accept();
            System.out.println("New connection accepted " +
connection.getInetAddress() +
                          ":" + connection.getPort());
            out = new ObjectOutputStream(connection.getOutputStream());
            out.flush();
            in = new ObjectInputStream(connection.getInputStream());
            InputStream in = connection.getInputStream();
            }
        catch(IOException ioException){
            ioException.printStackTrace();
        }
        finally{
            try{
                 providerSocket.close();
            }
            catch(IOException ioException){
                ioException.printStackTrace();
            }
        }
    }
public static void main(String args[])
    {
        Server server = new Server();
        while(true){
            server.run();
        }
    }
}

UWP app：

public sealed partial class MainPage : Page
    {
        public MainPage()
        {
            this.InitializeComponent();
            createSocket();
        }
        public async void createSocket()
        {
            MessageWebSocket webSock = new MessageWebSocket();
            webSock.Control.MessageType = SocketMessageType.Utf8;
            webSock.MessageReceived += webSock_MsgReceived;
            webSock.Closed += webSock_Closed;
            Uri serverUri = new Uri("ws://localhost:9999");
            try
            {
                await webSock.ConnectAsync(serverUri);
                tbConnect.Text = "Connected";
            }
            catch (Exception ex)
            {
                tbConnect.Text = ex.Message + " / " + ex.HResult + " / " + ex.Data;
            }
        }
}

Java错误：

    New connection accepted /0:0:0:0:0:0:0:1:63994
java.io.StreamCorruptedException: invalid stream header: 47455420
    at java.io.ObjectInputStream.readStreamHeader(Unknown Source)
    at java.io.ObjectInputStream.<init>(Unknown Source)
    at Provider.run(Provider.java:26)
    at Provider.main(Provider.java:73)
Waiting for connection