1 @Test 2     public void send() throws IOException { 3         DatagramChannel channel = DatagramChannel.open(); 4         channel.configureBlocking(false); 5  6         ByteBuffer byteBuffer = ByteBuffer.allocate(1024); 7  8         Scanner scanner = new Scanner(System.in); 9         SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");10         while (scanner.hasNext()) {11             String line = scanner.next();12             byteBuffer.put((format.format(new Date()) + ":" + line).getBytes());13             byteBuffer.flip();14 15             channel.send(byteBuffer, new InetSocketAddress("127.0.0.1", 9899));16             byteBuffer.clear();17         }18 19         channel.close();20     }21 22     @Test23     public void receive() throws IOException {24         DatagramChannel channel = DatagramChannel.open();25         channel.configureBlocking(false);26         channel.bind(new InetSocketAddress(9899));27 28         Selector selector = Selector.open();29         channel.register(selector, SelectionKey.OP_READ);30 31         while (selector.select() > 0) {32             Iterator<SelectionKey> selectionKeys = selector.selectedKeys().iterator();33             while (selectionKeys.hasNext()) {34                 SelectionKey selectionKey = selectionKeys.next();35                 if (selectionKey.isReadable()) {36                     ByteBuffer buffer = ByteBuffer.allocate(1024);37                     channel.receive(buffer);38                     buffer.flip();39                     System.out.println(new String(buffer.array(), 0, buffer.limit()));40                     buffer.clear();41                 }42 43                 selectionKeys.remove();44             }45         }46 47     }