利用NIO的Selector处理服务器-客户端模型

package NIOTEST;

import java.io.IOException;
import java.net.InetAddress;
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;
import java.util.Set;

public class NIOServer {
    public static void main(String[] args) throws IOException, InterruptedException {
        Selector selector = Selector.open();

        ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
        InetSocketAddress address = new InetSocketAddress(InetAddress.getLocalHost(), 8080);
        serverSocketChannel.socket().bind(address);
        serverSocketChannel.configureBlocking(false);
        serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);

        while (true) {
            if (selector.select() > 0) {
                Set<SelectionKey> selectionKeys = selector.selectedKeys();
                Iterator<SelectionKey> it = selectionKeys.iterator();
                while (it.hasNext()) {
                    SelectionKey selectionKey = it.next();
                    if (selectionKey.isAcceptable()) {
                        serverSocketChannel = (ServerSocketChannel)selectionKey.channel();
                        SocketChannel socketChannel = serverSocketChannel.accept();
                        socketChannel.configureBlocking(false);
                        socketChannel.register(selector, SelectionKey.OP_READ);
                        System.out.println("Connected: " + socketChannel.socket().getRemoteSocketAddress());
                    } else if (selectionKey.isReadable()) {
                        SocketChannel socketChannel = (SocketChannel) selectionKey.channel();
                        ByteBuffer buffer = ByteBuffer.allocate(1024);
                        while (socketChannel.read(buffer) > 0) {
                            buffer.flip();
                            byte[] dis = new byte[buffer.limit()];
                            buffer.get(dis);
                            System.out.println("当前线程="+Thread.currentThread().getId()+"--"+new String(dis));
                        }
                    }

                    it.remove();
                }
            }

            Thread.sleep(100);
        }
    }
}

客户端

package NIOTEST;

import java.io.IOException;
import java.net.InetAddress;
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.text.SimpleDateFormat;
import java.util.Date;
import java.util.Iterator;
import java.util.Set;
public class NIOClient {
    public static void main(String[] args) throws IOException {
        SocketChannel socketChannel = SocketChannel.open();
        InetSocketAddress address = new InetSocketAddress(InetAddress.getLocalHost(), 8080);
        socketChannel.socket().connect(address);

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

        ByteBuffer buffer = ByteBuffer.allocate(1024);
        while (true) {
            try {
                buffer.clear();
                String time = sdf.format(new Date());
                buffer.put(time.getBytes());
                buffer.flip();
                socketChannel.write(buffer);
                Thread.sleep(5000);
            } catch (Exception e) {
                System.out.println("Connection Close");
                break;
            }
        }
    }
}