服务器+客户端（Java）
首先执行服务器
package Demo03;import .DatagramPacket;import .DatagramSocket;//这边也是需要等待客户端的连接public class UdpServerDemo01 {public static void main(String[] args) throws Exception {//1.开放端口DatagramSocket socket = new DatagramSocket(9090);//2.接收数据（即接收包）byte[] buffer = new byte[1024];DatagramPacket packet = new DatagramPacket(buffer, 0, buffer.length);//接收//这里将 DatagramPacket封装 成一个对象socket.receive(packet); //阻塞接收System.out.println(packet.getAddress().getHostAddress());System.out.println(new String(packet.getData(),0,packet.getLength()));//3.关闭连接socket.close();}}
接着再执行客户端
package Demo03;import .DatagramPacket;import .DatagramSocket;import .InetAddress;//不要连接服务器public class UdpClientDemo01 {public static void main(String[] args) throws Exception {//1.建立一个SocketDatagramSocket socket = new DatagramSocket();//2.建个 包String msg="你好啊，服务器！";//接收对象InetAddress localhost = InetAddress.getByName("localhost");int port=9090;//以下解释：数据、数据长度起始、接收对象DatagramPacket packet = new DatagramPacket(msg.getBytes(), 0, msg.getBytes().length, localhost, port);//3.发送 包socket.send(packet);//4.关闭流（资源）socket.close();}}
