Question

这是一个非常简单的Java客户端/服务器应用程序。在这里，我尝试同步对ArrayList的访问。但是，抛出异常。而且我认为我已经保护了我应该做的一切。任何人都可以帮助解释这段代码的错误吗？还有什么需要注意的吗？

public class ChatServerSynchronized {

    public static void main(String[] args) {
        new ChatServerSynchronized().go();
    }

    private ArrayList<ClientHandler> clients;
    private int numOfClients;
    public ChatServerSynchronized() {
        clients = new ArrayList<ClientHandler>();
        numOfClients = 0;
    }
    public void go() {
        try {
            ServerSocket ss = new ServerSocket(10000);
            System.out.println("Listening at 10000");
            while(true) {
                Socket s = ss.accept();
                int thisClient = (++numOfClients); 
                ClientHandler client = new ClientHandler(thisClient, s);
                System.out.println("New connection: "+thisClient);
                addClient(client);

                new Thread(client).start();
            }
        } catch (IOException e) {
        }
    }
    public synchronized void addClient(ClientHandler client) {
        clients.add(client);
    }
    public synchronized void removeClient(ClientHandler client) {
        clients.remove(client);
    }
    public synchronized void broadcast(String message) {
        for(ClientHandler client: clients) {
            client.send(message);
        }
    }

    private class ClientHandler implements Runnable {
        private BufferedReader in;
        private PrintWriter out;
        private int id;
        public ClientHandler(int clientID, Socket s) throws IOException {
            id = clientID;
            in = new BufferedReader(new InputStreamReader(s.getInputStream()));
            out = new PrintWriter(s.getOutputStream());
        }
        public void run() {
            try {
                while(true) {
                    String message = in.readLine();
                    if(message == null)
                        break;
                    System.out.println(id+": Message '"+ message + "' received");
                    broadcast(id+": "+message);
                }
            } catch (IOException e) {
                //System.out.println(e);
                //This is where the exception is thrown
            } finally {
                System.out.println("Closed: "+id);
                removeClient(this);
            }
        }
        public void send(String message) {
            out.println(message);
            out.flush();
        }
    }

}

Answer 1

这可能是因为您关闭了客户端上的连接并将流保存在服务器上。因此，如果您写入已关闭的套接字（由客户端关闭） - ＆gt;错误。

即使你不写，我会在客户端停止连接/中止时立即出现错误。（有人应该确认这一点）在你的客户端设置一个Thread.sleep（5000）然后你可能在5秒后看到错误。：）

Jeerze，

西蒙

java SocketException：软件导致连接中止：recv失败

1 个答案: