java网络编程中tcp和udp

java网络编程中tcp和udp

在网络编程中，先启动service，再启动clent。
1.tcp
服务端

public class Service {

public static void main(String[] args) throws Exception {

ServerSocket ss = new ServerSocket(6666);

System.out.println("等待");

while (true) {

Socket socket  =ss.accept();

InputStream is = socket.getInputStream();

DataInputStream dataInputStream = new DataInputStream(is);

System.out.println(dataInputStream.readUTF());

dataInputStream.close();

socket.close();

}

}

}
客户端

public class CientSocket {

public static void main(String[] args) throws Exception {

Socket socket = new Socket("127.0.0.1",6666);

OutputStream outputStream = socket.getOutputStream();

DataOutputStream dataOutputStream = new DataOutputStream(outputStream);

dataOutputStream.writeUTF("333333333");

dataOutputStream.flush();

dataOutputStream.close();

socket.close();

}

}

udp通信，是不区分客户端和服务端的

public class Service {

public static void main(String[] args) throws Exception {

byte buf[] = new byte[1024];

DatagramPacket dPacket = new DatagramPacket(buf, buf.length);

DatagramSocket dSocket = new DatagramSocket(5678);

while (true) {

dSocket.receive(dPacket);

System.out.println(new String(buf,0,dPacket.getLength()));

}

}

}

public class UdpClient {

public static void main(String[] args) throws Exception{

while (true) {

byte[] buf = (new String("hello")).getBytes();

DatagramPacket dpPacket = new DatagramPacket(buf, buf.length, new InetSocketAddress("127.0.0.1", 5678));

//自己占用9999端口

DatagramSocket dSocket = new DatagramSocket(9999);

dSocket.send(dpPacket);

dSocket.close();

}

}

}