![](https://images2017.cnblogs.com/blog/725061/201712/725061-20171213174020097-963118806.png)
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
public class test_udp_send {
public static void main(String arg[]) throws Exception{
DatagramSocket dSocket=new DatagramSocket(3000);
String string ="Hello,word";
DatagramPacket datagramPacket=new DatagramPacket(string.getBytes(), string.length(),InetAddress.getByName("127.0.0.1"),8001);
dSocket.send(datagramPacket);
dSocket.close();
}
}
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
public class test_udp_server {
public static void main(String args[]) throws Exception{
byte buf[]=new byte[1024];
DatagramSocket dSocket= new DatagramSocket(8001);
DatagramPacket datagramPacket=new DatagramPacket(buf, 1024);
dSocket.receive(datagramPacket);
String str=new String(datagramPacket.getData());
System.out.println(str);
dSocket.close();
}
}
![](https://images2017.cnblogs.com/blog/725061/201712/725061-20171213174111988-1784355978.png)
import java.io.IOException;
import java.io.InputStream;
import java.net.InetAddress;
import java.net.Socket;
public class test_tcp_send {
public static void main(String arg[]) throws Exception{
new client().connect();
}
}
class client{
public void connect() throws Exception, IOException{
Socket client=new Socket(InetAddress.getLocalHost(),8009);
InputStream inputStream=client.getInputStream();
byte buf[]=new byte[1024];
int length=inputStream.read(buf);
System.out.println(new String(buf));
client.close();
}
}
public class test_tcp_server {
public static void main(String args[]) throws Exception
{
new server().connect();
}
}
class server{
public void connect() throws Exception{
ServerSocket serverSocket=new ServerSocket(8009);
Socket client=serverSocket.accept();
OutputStream outputStream=client.getOutputStream();
outputStream.write("hello,word".getBytes());
outputStream.close();
client.close();
}
}