Groovy Tcp клиент / сервер, отправляющий карты

Question

Я создал базовый tcp-клиент и сервер в Groovy, и я хочу отправить карты с сервера на клиент, мне интересно, могу ли я отправлять карты по-прежнему и все еще иметь доступ к значениям.

//TCP Server
def book1 = [Title of Book: "Groovy Recipes", Author: "Scott Davis", Number of Pages: "241"]

server = new ServerSocket(2000)

println("Waiting for connection")

while(true) {
    server.accept() { socket ->
        socket.withStreams { input, output ->   

            w = new BufferedWriter(new OutputStreamWriter(output))
            String message = "Connection was successful"

            r = new BufferedReader(new InputStreamReader(input))

            while(true) {

                if(message != null) {
                    w.writeLine(message)
                    w.flush()
                    message = null
                }

                String a = r.readLine()

                if(a=="book1") {
                    message = book1
                } else {
                    message = "$a command unknown."
                    sendMessage(message)
                    println message
                    message = null
                }
            }
        }
    }
}

def sendMessage(String msg) {
    try {
        w.writeLine(msg)
        w.flush();
    } catch(IOException ioException) {
        ioException.printStackTrace();
    }
}

Вот мой клиент (где я хочу получить карту и получить значения)

//TCP Client

def grabBookInfo {
    queryData()  
}

public void queryData() {
    def hosts = ["localhost"]

    for(int aHost = 0; aHost < hosts.size; aHost++) {
        bookClient(hosts[aHost]);
    }
}

public void bookClient() {
    def commands = ["book1"]
    def answers = [commands.size]

    def requestSocket = new Socket(host, 2000)

    r = new BufferedReader(new InputStreamReader(requestSocket.getInputStream()));
    w = new BufferedWriter(new OutputStreamWriter(requestSocket.getOutputStream()));

    String message = "Connection was successful"

    message = r.readLine()
    println("Server>" + message)

    for(int n = 0; n < commands.size; n++) {
        sendMessage(commands[n]);
        answers[n] = r.readLine()
    }

    //get map values here
    //answers[0] = Book
    //println Book.['Title of Book']
    //println Book.['Author']
    //println Book.['Number of Pages']

    w.flush()
    w.close()
}

public void sendMessage(msg) {
    w.write(msg+"\r\n");
    w.flush();
    System.out.println("client>" + msg);
    }   
}

Я на правильном пути?

Answer 1

На сервере используйте ObjectOutputStream. В клиенте используйте ObjectInputStream.

Сервер:

private static final HashMap<String, Integer> TEST_MAP;
static {
    TEST_MAP = new HashMap<String, Integer>();
    TEST_MAP.put("one", 1);
    TEST_MAP.put("two", 2);
}
...

ServerSocket ss = new ServerSocket(port);
Socket socket = ss.accept();
ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream()); 
out.writeObject(TEST_MAP);
out.close();

Клиент:

Socket socket = new Socket(HOST, PORT);
ObjectInputStream in = new ObjectInputStream(socket.getInputStream());
Object o = in.readObject();
assert o instanceof HashMap<?, ?>;
@SuppressWarnings("unchecked")
HashMap<String, Integer> m = (HashMap<String, Integer>)o;
assertTrue(m.get("one") == 1);
assertTrue(m.get("two") == 2);
in.close();
socket.close();

Answer 2

Сериализация карт, пример

http://www.java2s.com/Tutorial/Java/0140__Collections/SerializingHashMaps.htm