NIO模式的IO多路复用底层原理

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产生缘由

底层原理关键词

Nio技术多路IO复用底层实现原理

手写伪NIO代码

public class SocketNioTcpServer {
    private static List<SocketChannel> listSocketChannel = new ArrayList<>();
    private static ByteBuffer byteBuffer = ByteBuffer.allocate(512);

    public static void main(String[] args) {
        try {
            // 1.创建一个ServerSocketChannel
            ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
            // 2. 绑定地址
            ServerSocketChannel bind = serverSocketChannel.bind(new InetSocketAddress(9090));
            serverSocketChannel.configureBlocking(false);
            while (true) {
                /**channel管道：TCP数据传输的通道*/
                SocketChannel socketChannel = serverSocketChannel.accept();
                if (socketChannel != null) {
                    /**通道加入到选择器中*/
                    socketChannel.configureBlocking(false);
                    listSocketChannel.add(socketChannel);
                }
                /**轮询选择器下的所有通道信息，利用buffer缓存机制读取数据*/
                for (SocketChannel scl : listSocketChannel) {
                    try {
                        int read = scl.read(byteBuffer);
                        if (read > 0) {
                            byteBuffer.flip();
                            Charset charset = Charset.forName("UTF-8");
                            String receiveText = charset.newDecoder().decode
                                    (byteBuffer.asReadOnlyBuffer()).toString();
                            System.out.println(Thread.currentThread().getName()+" receiveText:" + receiveText);
                        }
                        listSocketChannel.remove(scl);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

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