Java BOI与NIO超详细实例精讲

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("服务端启动");
        while (true) {
            System.out.println("等待链接...");
            Socket socket = serverSocket.accept();
            pool.execute(() -> {
                handler(socket);
            });
        }
    }
    private static void handler(Socket socket) {
        try {
            System.out.println("有一个客户端接入：" + Thread.currentThread().getName());
            byte[] bytes = new byte[1024];
            //通过socket 获取输入流
            InputStream inputStream = socket.getInputStream();
            //循环读取客户端发送的数据
            while (true) {
                System.out.println("等待读取数据...");
                int read = inputStream.read(bytes);
                if (read != -1) {
                    //输出客户端读取的数据
                    System.out.println("线程信息：" + Thread.currentThread().getName());
                    System.out.println(new String(bytes, 0, read));
                } else {
                    break;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            System.out.println("关闭client链接：" + 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();
        //注册客户端链接事件到selector
        serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
        while (true) {
            int select = selector.select(1000L);
            if (select == 0) {
                System.out.println("等待1秒，没有事件发生");
                continue;
            }
            //监听到相关事件发生，读取SelectionKey集合，遍历处理所有事件
            Iterator<SelectionKey> keyIterator = selector.selectedKeys().iterator();
            while (keyIterator.hasNext()) {
                SelectionKey key = keyIterator.next();
                if (key.isAcceptable()) {
                    SocketChannel socketChannel = serverSocketChannel.accept();
                    System.out.println("客户端链接成功，生成一个sockeChannel " + socketChannel.hashCode());
                    //将socketChannel设置为非阻塞
                    socketChannel.configureBlocking(false);
                    //注册内容读取事件到selector，同时关联一个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("读取到数据: " + new String(byteBuffer.array(), 0, read));
                    } catch (Exception e) {
                        if (channel != null) {
                            channel.close();
                        }
                        e.printStackTrace();
                    }
                }
                //手动从集合中移除当前的SelectionKey，防止重复操作
                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("链接未完成，客户端不会阻塞....");
            }
        }
        String str = "Hello,你好~~~";
        ByteBuffer byteBuffer = ByteBuffer.wrap(str.getBytes());
        socketChannel.write(byteBuffer);
        System.in.read();
    }
}