public class BioServer {
    static ExecutorService executorService = Executors.newCachedThreadPool();
    public static void main(String[] args) {
        try {
            // 啟動(dòng)服務(wù)，綁定8080端口
            ServerSocket serverSocket = new ServerSocket();
            serverSocket.bind(new InetSocketAddress(8080));
            System.out.println("開啟服務(wù)");
            while (true){
                System.out.println("等待客戶端建立連接");
                // 監(jiān)聽8080端口，獲取客戶端連接
                Socket socket = serverSocket.accept(); //阻塞
                System.out.println("建立連接："+socket);
                executorService.submit(()->{
                    //業(yè)務(wù)處理
                    try {
                        handler(socket);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                });
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            //TODO 資源回收
        }
    }
    private static void handler(Socket socket) throws IOException {
        byte[] bytes = new byte[1024];
        System.out.println("等待讀取數(shù)據(jù)");
        int read = socket.getInputStream().read(bytes); // 阻塞
        if(read !=-1) {
            System.out.println("讀取客戶端發(fā)送的數(shù)據(jù)：" +
                    new String(bytes, 0, read));
        }
    }
}

public class NioServer {
    public static void main(String[] args)  {
        List<SocketChannel> list = new ArrayList<>();  // 緩存所有的socket
        ByteBuffer byteBuffer = ByteBuffer.allocate(1024); // 緩存區(qū)的大小
        try {
            ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
            // 監(jiān)聽8080
            serverSocketChannel.bind(new InetSocketAddress(8080));
            // channel非阻塞
            serverSocketChannel.configureBlocking(false);
            System.out.println("NioServer 啟動(dòng)....");
            while (true){
                // 非阻塞
                SocketChannel socketChannel = serverSocketChannel.accept();
                Thread.sleep(1000);
                if(socketChannel == null){
                    System.out.println("沒有新的客戶端建立連接");
                }else {
                    System.out.println("新的客戶端建立連接");
                    // channel非阻塞
                    socketChannel.configureBlocking(false);
                    // 將新的socket添加到 list
                    list.add(socketChannel);
                }
                //遍歷所有的socket
                for(SocketChannel channel:list){
                    //非阻塞
                    int read = channel.read(byteBuffer);
                    if(read >0) {
                        //讀模式
                        byteBuffer.flip();
                        System.out.println("讀取客戶端發(fā)送的數(shù)據(jù)：" +new String(byteBuffer.array(),0,read));
                        byteBuffer.clear();
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

public class AioServer {
    public AsynchronousServerSocketChannel serverSocketChannel;
    public static void main(String[] args) throws Exception {
        new AioServer().listen();
        Thread.sleep(Integer.MAX_VALUE);
    }
    private void listen() throws IOException {
        //1. 創(chuàng)建一個(gè)線程池
        ExecutorService es = Executors.newCachedThreadPool();
        //2. 創(chuàng)建異步通道群組
        AsynchronousChannelGroup acg = AsynchronousChannelGroup.withCachedThreadPool(es, 1);
        //3. 創(chuàng)建服務(wù)端異步通道
        serverSocketChannel = AsynchronousServerSocketChannel.open(acg);
        //4. 綁定監(jiān)聽端口
        serverSocketChannel.bind(new InetSocketAddress(8080));
        System.out.println("AioServer 啟動(dòng)....");
        //5. 監(jiān)聽連接，傳入回調(diào)類處理連接請求
        serverSocketChannel.accept(this, new CompletionHandler<AsynchronousSocketChannel, AioServer>() {
            //
            //            //具體處理連接請求的就是completed方法，它有兩個(gè)參數(shù)：第一個(gè)是異步通道，第二個(gè)就是上面?zhèn)魅氲腁ioServer對象
            @Override
            public void completed(AsynchronousSocketChannel socketChannel, AioServer attachment) {
                try {
                    if (socketChannel.isOpen()) {
                        System.out.println("接收到新的客戶端的連接，地址："
                                + socketChannel.getRemoteAddress());
                        final ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
                        //調(diào)用 read 函數(shù)讀取客戶端發(fā)送的數(shù)據(jù)
                        socketChannel.read(byteBuffer, socketChannel,
                                        new CompletionHandler<Integer, AsynchronousSocketChannel>() {
                                            @Override
                            public void completed(Integer result, AsynchronousSocketChannel attachment) {
                                try {
                                    //讀取請求，處理客戶端發(fā)送的數(shù)據(jù)
                                    byteBuffer.flip();
                                    String content = Charset.defaultCharset()
                                            .newDecoder().decode(byteBuffer).toString();
                                    System.out.println("服務(wù)端接受到客戶端發(fā)來的數(shù)據(jù)：" + content);
                                } catch (CharacterCodingException e) {
                                    e.printStackTrace();
                                }
                            }
                            @Override
                            public void failed(Throwable exc, AsynchronousSocketChannel attachment) {
                                exc.printStackTrace();
                                try {
                                    attachment.close();
                                } catch (IOException e) {
                                    e.printStackTrace();
                                }
                            }
                        });
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }finally {
                    //當(dāng)有新的客戶端接入的時(shí)候，直接調(diào)用accept的方法
                    attachment.serverSocketChannel.accept(attachment, this);
                }
            }
            @Override
            public void failed(Throwable exc, AioServer attachment) {
                exc.printStackTrace();
            }
        });
    }
}