Java nio服务端对同一个消息多次select如何处理

Question

服务端代码

        private void listen() throws IOException {
        SocketChannel client;
        while (selector.select() > 0) {
            System.out.println("select");
            Set<SelectionKey> selectionKeys = selector.selectedKeys();
            Iterator<SelectionKey> keyIterator = selectionKeys.iterator();
            while (keyIterator.hasNext()) {
                SelectionKey key = keyIterator.next();
                //置空迭代器
                keyIterator.remove();
                try {
                    if (key.isAcceptable()) {
                        server = (ServerSocketChannel) key.channel();
                        client = server.accept();
                        client.configureBlocking(false);
                        client.register(selector,SelectionKey.OP_READ);
                    }else if (key.isReadable()) {
                        System.out.println("read");
                        ByteBuffer readBuffer = ByteBuffer.allocate(1024);
                        SocketChannel readChannel = (SocketChannel) key.channel();
                        readChannel.read(readBuffer);
                        readBuffer.flip();
                        int i = readBuffer.getInt();
                        System.out.println("输出 " +i);
                    }
                    if (key.isWritable()) {

                    }
                }catch (IOException e) {
                    key.channel().close();
                    key.cancel();
                }
            }
        }
    }

客户端代码

     ByteBuffer writeBuffer = ByteBuffer.allocate(1024);
        writeBuffer.putInt(111);
        try {
            client.write(writeBuffer);
        } catch (IOException e) {
            e.printStackTrace();
        }

服务端输出3次select 其中一次是连接accept 一次是接收消息 还有一次呢？
另外 在另一个程序中 服务端不断地对同一个消息处理 大概6次直到报错（这个程序是持续连接 另起线程）
求助

Answer 1

还有一次write，你服务端时刻缓冲区可写。