套接字ObjectInputStream和ObjectOutputStream不起作用

Question

I tried a simple client server with ObjectInputStream and ObjectOutputStream instead BufferedReader and BufferedWriter but this code don't want to work . This is the code

[CLIENT]

[CODE]

public class MainClient {

public static final String SERVER_ADDRESS_STRING = "192.168.0.2";
public static final int PORT_NO = 8000;
private static ObjectInputStream ois;
private static ObjectOutputStream oos;

public static void main(String[] args) {

    Socket socket = null;
    try {
        socket = new Socket(SERVER_ADDRESS_STRING, PORT_NO);
    } catch (IOException e1) {
        e1.printStackTrace();
    }

    System.out.println("Client : 1");

    try {
        ois = new ObjectInputStream(socket.getInputStream());
    } catch (IOException e) {
        e.printStackTrace();
    }

    System.out.println("Client : 2");

    try {
        oos = new ObjectOutputStream(socket.getOutputStream());
        oos.flush();
    } catch (IOException e) {
        e.printStackTrace();
    }

    System.out.println("Client : 3");

    //Diffie-Hellman
    try {
        @SuppressWarnings("unused")
        BigInteger shared_key = DiffieHellmanExchangeClient(socket, ois, oos);
        System.out.println(shared_key);
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    }   

    try {
        socket.close();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

[\\CODE]

[SERVER]

[CODE]

public class MainServer {

public static final int PORT_NO = 8000;
private static final int BACKLOG_NO = 10;
private static ObjectInputStream ois;
private static ObjectOutputStream oos;

public static void main(String[] args) {

    ServerSocket sslserver = null;
    try {
        sslserver = new ServerSocket(PORT_NO, BACKLOG_NO);
    } catch (IOException e2) {
        e2.printStackTrace();
    }

    System.out.println("Server : 1");
    Socket socket = null;
    try {
        socket = (Socket) sslserver.accept();
    } catch (IOException e1) {
        e1.printStackTrace();
    }

    System.out.println("Server : 2");

    try {
        ois = new ObjectInputStream(socket.getInputStream());
    } catch (IOException e) {
        e.printStackTrace();
    }

    System.out.println("Server : 3");

    try {
        oos = new ObjectOutputStream(socket.getOutputStream());
        oos.flush();
    } catch (IOException e) {
        e.printStackTrace();
    }

    System.out.println("Server : 4");

    //Diffie-Hellman
    try {
        @SuppressWarnings("unused")
        BigInteger shared_key = DiffieHellmanExchangeServer(socket, ois, oos);
        System.out.println(shared_key);
    } catch (ClassNotFoundException | IOException e) {
        e.printStackTrace();
    }

    try {
        socket.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
    try {
        sslserver.close();
    } catch (IOException e) {
        e.printStackTrace();
    }

}

[\\CODE]

The problem is that the client and server are blocked on ois = new ObjectInputString.

Why?

Answer 1

在ObjectInputStream之前创建ObjectOutputStream，否则会出现死锁。