暂未考虑花大时间去学这些底层代码，直接进入框架的学习，代码来自网络

 

Server

package spring.server;import java.io.IOException;import java.net.InetSocketAddress;import java.nio.ByteBuffer;import java.nio.channels.SelectionKey;import java.nio.channels.Selector;import java.nio.channels.ServerSocketChannel;import java.nio.channels.SocketChannel;import java.nio.charset.Charset;import java.util.Iterator;public class Server {    /*     * 处理器类     */    static class Handler {        private int bufferSize = 1024; // 缓冲器容量        private String localCharset = "UTF-8"; // 编码格式        public Handler() {        }        public Handler(int bufferSize) {            this(bufferSize, null);        }        public Handler(String localCharset) {            this(-1, localCharset);        }        public Handler(int bufferSize, String localCharset) {            if (bufferSize > 0) {                this.bufferSize = bufferSize;            }            if (localCharset != null) {                this.localCharset = localCharset;            }        }        /*         * 连接请求处理方法         */        public void handleAccept(SelectionKey selectionKey) throws IOException {            // 通过选择器键获取服务器套接字通道，通过accept()方法获取套接字通道连接            SocketChannel socketChannel = ((ServerSocketChannel) selectionKey.channel()).accept();            // 设置套接字通道为非阻塞模式            socketChannel.configureBlocking(false);            // 为套接字通道注册选择器，该选择器为服务器套接字通道的选择器，即选择到该SocketChannel的选择器            // 设置选择器关心请求为读操作，设置数据读取的缓冲器容量为处理器初始化时候的缓冲器容量            socketChannel.register(selectionKey.selector(), SelectionKey.OP_READ, ByteBuffer.allocate(bufferSize));        }        public void handleRead(SelectionKey selectionKey) throws IOException {            // 获取套接字通道            SocketChannel socketChannel = (SocketChannel) selectionKey.channel();            // 获取缓冲器并进行重置,selectionKey.attachment()为获取选择器键的附加对象            ByteBuffer byteBuffer = (ByteBuffer) selectionKey.attachment();            byteBuffer.clear();            // 没有内容则关闭通道            if (socketChannel.read(byteBuffer) == -1) {                socketChannel.close();            } else {                // 将缓冲器转换为读状态                byteBuffer.flip();                // 将缓冲器中接收到的值按localCharset格式编码保存                String receivedRequestData = Charset.forName(localCharset).newDecoder().decode(byteBuffer).toString();                System.out.println("接收到客户端的请求数据：" + receivedRequestData);                // 返回响应数据给客户端                String responseData = "已接收到你的请求数据，响应数据为：(响应数据)";                byteBuffer = ByteBuffer.wrap(responseData.getBytes(localCharset));                socketChannel.write(byteBuffer);                // 关闭通道                socketChannel.close();            }        }    }    public static void main(String[] args) {        try {            // 创建ServerSocketChannel通道，绑定监听端口为8080            ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();            serverSocketChannel.socket().bind(new InetSocketAddress(8080));            // 设置为非阻塞模式            serverSocketChannel.configureBlocking(false);            // 注册选择器,设置选择器选择的操作类型            Selector selector = Selector.open();            serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);            // 创建处理器            Handler handler = new Handler(1204);            while (true) {                // 等待请求，每次等待阻塞3s，超过时间则向下执行，若传入0或不传值，则在接收到请求前一直阻塞                if (selector.select(3000) == 0) {                    System.out.println("等待请求超时......");                    continue;                }                System.out.println("-----处理请求-----");                // 获取待处理的选择键集合                Iterator
     
       keyIterator = selector.selectedKeys().iterator();                while (keyIterator.hasNext()) {                    SelectionKey selectionKey = keyIterator.next();                    try {                        // 如果是连接请求，调用处理器的连接处理方法                        if (selectionKey.isAcceptable()) {                            handler.handleAccept(selectionKey);                        }                        // 如果是读请求，调用对应的读方法                        if (selectionKey.isReadable()) {                            handler.handleRead(selectionKey);                        }                    } catch (IOException e) {                        keyIterator.remove();                        continue;                    }                }                // 处理完毕从待处理集合移除该选择键                keyIterator.remove();            }        } catch (IOException e) {            e.printStackTrace();        }    }}
     

Client

package spring.server;import java.io.IOException;import java.net.InetSocketAddress;import java.nio.ByteBuffer;import java.nio.channels.SocketChannel;public class Client {    public static void main(String[] args) throws IOException {        SocketChannel socketChannel = SocketChannel.open();        socketChannel.connect(new InetSocketAddress("127.0.0.1", 8080));        String newData = "New String to write to file..." + System.currentTimeMillis();        ByteBuffer buf = ByteBuffer.allocate(48);        buf.clear();        buf.put(newData.getBytes());        buf.flip();        while (buf.hasRemaining()) {            socketChannel.write(buf);        }//        socketChannel.configureBlocking(false);//        socketChannel.connect(new InetSocketAddress("http://jenkov.com", 80));////        while(! socketChannel.finishConnect() ){//            //wait, or do something else...    //        }                socketChannel.close();    }}