java,NIO非阻塞式网络通信DEMO.

    @Test
    public void client() throws IOException {

        SocketChannel sChannel = SocketChannel.open(new InetSocketAddress("127.0.0.1", 9898));

        //切换非阻塞模式
        sChannel.configureBlocking(false);

        ByteBuffer buffer = ByteBuffer.allocate(1024);

        //4.发送数据给服务器

        buffer.put("zzzzz".getBytes());
        buffer.flip();
        sChannel.write(buffer);

        sChannel.close();

    }

    @Test
    public void server() throws IOException {

        //1.获取通道
        ServerSocketChannel ssChannel = ServerSocketChannel.open();

        //2.切换非阻塞模式
        ssChannel.configureBlocking(false);

        //3.绑定连接
        ssChannel.bind(new InetSocketAddress(9898));

        //4. 获取选择器
        Selector selector = Selector.open();

        //5.将通道注册到选择器上,并且指定 监听接受时间
        ssChannel.register(selector, SelectionKey.OP_ACCEPT);

        ///6.轮询式的获取选择器上已经'准备就绪'的事件
        while (selector.select() > 0) {
            //7. 获取当前选择器中所有注册的“选择键(已就绪的监听事件)”
            Iterator it = selector.selectedKeys().iterator();

            while (it.hasNext()) {

                //8. 获取准备“就绪”的是事件
                SelectionKey sk = it.next();

                //9.判断具体是什么事件准备就绪
                if (sk.isAcceptable()) {
                    //10. 若“接收就绪”，获取客户端连接
                    SocketChannel accept = ssChannel.accept();
                    //切换到非阻塞模式
                    accept.configureBlocking(false);
                    //将改通道注册到选择器
                    accept.register(selector, SelectionKey.OP_READ);


                } else if (sk.isReadable()) {
                    //13. 获取当前选择器上“读就绪”状态的通道
                    SocketChannel channel = (SocketChannel) sk.channel();

                    //14.读取数据
                    ByteBuffer buffer = ByteBuffer.allocate(1024);

                    int len = 0;

                    while ((len = channel.read(buffer)) > 0) {
                        buffer.flip();
                        System.out.println(new String(buffer.array(), 0, len));
                        buffer.clear();
                    }


                }

                //15. 取消选择键 SelectionKey
                it.remove();
            }
        }
    }