socket编程

# bio 

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

public class SocketServer {

    public static void main(String[] args) throws Exception{
        ServerSocket serverSocket = new ServerSocket(9000);
        while (true) {
            System.out.println("Start to accept.");
            Socket socket = serverSocket.accept();
            new Thread(() -> {
                try {
                    handler(socket);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }).start();
        }
    }

    public static void handler(Socket socket) throws IOException{
        byte[] bytes = new byte[1024];
        int read = socket.getInputStream().read(bytes);
        if (read != -1) {
            System.out.println(new String(bytes, 0, read));
        }
    }
}

# nio
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.util.*;

public class SocketServer {

    private static final Set<SocketChannel> socketChannels = new HashSet<>();
    public static void main(String[] args) throws Exception{
        ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
        serverSocketChannel.socket().bind(new InetSocketAddress(9000));
        serverSocketChannel.configureBlocking(false);

        while (true) {
            SocketChannel socketChannel = serverSocketChannel.accept();
            if (socketChannel != null) {
                socketChannel.configureBlocking(false);
                socketChannels.add(socketChannel);
            }
            Iterator iterator = socketChannels.iterator();
            while (iterator.hasNext()) {
                SocketChannel socketChannel1 = (SocketChannel) iterator.next();
                ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
                int len = socketChannel1.read(byteBuffer);
                if (len > 0) {
                    System.out.println(new String(byteBuffer.array()));
                }
                if (len == -1){
                    socketChannels.remove(socketChannel1);
                }
            }
        }
    }
}