java nio 例子

代码

public static void main(String[] args) throws Exception {
        // 创建通道和选择器
        ServerSocketChannel socketChannel = ServerSocketChannel.open();
        Selector selector = Selector.open();
        InetSocketAddress inetSocketAddress = new InetSocketAddress(
                InetAddress.getLocalHost(), 4700);
        socketChannel.socket().bind(inetSocketAddress);
        // 设置通道非阻塞 绑定选择器
        socketChannel.configureBlocking(false);
        socketChannel.register(selector, SelectionKey.OP_ACCEPT);
        System.out.println("Server started .... port:4700");

        listener(selector);

    }
    public static void listener(Selector in_selector) {
        try {
            while (true) {
                in_selector.select(); // 阻塞 直到有就绪事件为止
                Set<SelectionKey> readySelectionKey = in_selector
                        .selectedKeys();
                Iterator<SelectionKey> it = readySelectionKey.iterator();
                while (it.hasNext()) {
                    SelectionKey selectionKey = it.next();
                    // 判断是哪个事件
                    if (selectionKey.isAcceptable()) {// 客户请求连接
                        System.out.println(selectionKey.attachment()
                                + " - 接受请求事件");

                    }
                    if (selectionKey.isReadable()) {// 读数据
                        System.out.println(" - 读数据事件");
                    }
                    if (selectionKey.isWritable()) {// 写数据
                        System.out.println(" - 写数据事件");
                    }
                    if (selectionKey.isConnectable()) {
                        System.out.println(" - 连接事件");
                    }
                    // 必须removed 否则会继续存在，下一次循环还会进来,
                    // 注意removed 的位置，针对一个.next() remove一次
                    it.remove();
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

    }