import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class BIOServerTest {
    public static void main(String[] args) throws Exception {
        ExecutorService pool = Executors.newCachedThreadPool();
        ServerSocket serverSocket = new ServerSocket(8888);
        System.out.println("服務(wù)端啟動(dòng)");
        while (true) {
            System.out.println("等待鏈接...");
            Socket socket = serverSocket.accept();
            pool.execute(() -> {
                handler(socket);
            });
        }
    }
    private static void handler(Socket socket) {
        try {
            System.out.println("有一個(gè)客戶(hù)端接入：" + Thread.currentThread().getName());
            byte[] bytes = new byte[1024];
            //通過(guò)socket 獲取輸入流
            InputStream inputStream = socket.getInputStream();
            //循環(huán)讀取客戶(hù)端發(fā)送的數(shù)據(jù)
            while (true) {
                System.out.println("等待讀取數(shù)據(jù)...");
                int read = inputStream.read(bytes);
                if (read != -1) {
                    //輸出客戶(hù)端讀取的數(shù)據(jù)
                    System.out.println("線(xiàn)程信息：" + Thread.currentThread().getName());
                    System.out.println(new String(bytes, 0, read));
                } else {
                    break;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            System.out.println("關(guān)閉client鏈接：" + Thread.currentThread().getName());
            try {
                socket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

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.util.Iterator;
public class NIOServer {
    public static void main(String[] args) throws Exception {
        ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
        InetSocketAddress inetSocketAddress = new InetSocketAddress(7000);
        serverSocketChannel.socket().bind(inetSocketAddress);
        serverSocketChannel.configureBlocking(false);
        Selector selector = Selector.open();
        //注冊(cè)客戶(hù)端鏈接事件到selector
        serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
        while (true) {
            int select = selector.select(1000L);
            if (select == 0) {
                System.out.println("等待1秒，沒(méi)有事件發(fā)生");
                continue;
            }
            //監(jiān)聽(tīng)到相關(guān)事件發(fā)生，讀取SelectionKey集合，遍歷處理所有事件
            Iterator<SelectionKey> keyIterator = selector.selectedKeys().iterator();
            while (keyIterator.hasNext()) {
                SelectionKey key = keyIterator.next();
                if (key.isAcceptable()) {
                    SocketChannel socketChannel = serverSocketChannel.accept();
                    System.out.println("客戶(hù)端鏈接成功，生成一個(gè)sockeChannel " + socketChannel.hashCode());
                    //將socketChannel設(shè)置為非阻塞
                    socketChannel.configureBlocking(false);
                    //注冊(cè)內(nèi)容讀取事件到selector，同時(shí)關(guān)聯(lián)一個(gè)Buffer
                    socketChannel.register(selector, SelectionKey.OP_READ, ByteBuffer.allocate(1024));
                }
                if (key.isReadable()) {
                    SocketChannel channel = null;
                    try {
                        channel = (SocketChannel) key.channel();
                        ByteBuffer byteBuffer = (ByteBuffer) key.attachment();
                        int read = channel.read(byteBuffer);
                        System.out.println("讀取到數(shù)據(jù): " + new String(byteBuffer.array(), 0, read));
                    } catch (Exception e) {
                        if (channel != null) {
                            channel.close();
                        }
                        e.printStackTrace();
                    }
                }
                //手動(dòng)從集合中移除當(dāng)前的SelectionKey，防止重復(fù)操作
                keyIterator.remove();
            }
        }
    }
}

import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SocketChannel;
public class NIOClient {
    public static void main(String[] args) throws Exception {
        SocketChannel socketChannel = SocketChannel.open();
        socketChannel.configureBlocking(false);
        InetSocketAddress inetSocketAddress = new InetSocketAddress("127.0.0.1", 7000);
        if (!socketChannel.connect(inetSocketAddress)){
            while (!socketChannel.finishConnect()){
                System.out.println("鏈接未完成，客戶(hù)端不會(huì)阻塞....");
            }
        }
        String str = "Hello,你好~~~";
        ByteBuffer byteBuffer = ByteBuffer.wrap(str.getBytes());
        socketChannel.write(byteBuffer);
        System.in.read();
    }
}