JavaNIO实现阻塞式UDP通信

服务端

import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.ProtocolFamily;
import java.net.SocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.DatagramChannel;
import java.util.Scanner;
import java.util.Date;
public class Server{
	public static void main(String[] args) throws IOException{
        DatagramChannel channel = DatagramChannel.open();
        channel.bind(new InetSocketAddress(8989));
        ByteBuffer buffer = ByteBuffer.allocate(1024);
        while (true) {
            SocketAddress receive = channel.receive(buffer);
            buffer.flip();//切换读取数据的模式
            String str = new String(buffer.array(), 0, buffer.limit());
            System.out.println(new Date());
            System.out.println(str);

            buffer.clear();//清空缓冲区
            buffer.put(("服务器已收到消息("+new Date() +"):" + str).getBytes());
            buffer.flip();//切换读取数据的模式
            channel.send(buffer, receive);
            buffer.clear();//清空缓冲区

            if (str.equals("quit")) {
                break;
            }
        }
        channel.close();
	}
}

客户端

import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.ProtocolFamily;
import java.net.SocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.DatagramChannel;
import java.util.Scanner;
import java.util.Date;
public class Client{
	public static void main(String[] args) throws IOException{
        //获得通道
        DatagramChannel channel = DatagramChannel.open();
        //获得SocketAddress对象
        InetSocketAddress address = new InetSocketAddress("127.0.0.1", 8989);
        Scanner sc = new Scanner(System.in);
        ByteBuffer buffer = ByteBuffer.allocate(1024);
        System.out.print(">");
        while (sc.hasNext()) {
            String str = sc.next();
            buffer.put(str.getBytes());
            buffer.flip();
            channel.send(buffer, address);

            buffer.clear();
            channel.receive(buffer);
            buffer.flip();
            System.out.println(new String(buffer.array() , 0 ,buffer.limit()));

            buffer.clear();
            System.out.print(">");

            if (str.equals("quit")) {
                break;
            }
        }
        sc.close();
        channel.close();
	}
}

运行结果截图