Java socket based on UDP/IP protocol

Java socket based on UDP/IP protocol application

Server side: 1, create Datagramsocket, specify port number

2. Create Datagrampacket

3, receive the data sent by the client

4. Read data

Client:

1. Define send message: The IP port number of the server to send the content

2. Create a datagrampacket that contains the information that will be sent

3. Create Datagramsocket

4. Send data

Server-side

Import java.io.IOException;
Import Java.net.DatagramPacket;
Import Java.net.DatagramSocket;
Import java.net.InetAddress;
Import java.net.SocketException;

/**
* server-side, implementation of UDP-based user login
* Created by Jim Calark on 2017/3/19.
*/
public class Udpserver {
public static void Main (String[]args) throws SocketException, ioexception{
1. Create server-side datagramsocket, specify port
Datagramsocket datagramsocket = new Datagramsocket (8800);
2. Create a datagram to accept data sent by the client
byte []data = new byte[1024];//creating byte array, specifying the size of the accepted datagram
Datagrampacket datagrampacket = new Datagrampacket (data,data.length);
3, receive the data sent by the client
System. out. println ("Server is turned on, waiting for client Connection");
This method will block until the data is received
Datagramsocket.receive (Datagrampacket);
4, read the data sent by the client
Parameter: Data to be converted array 0 starting from subscript 0 of the array datagrampacket.getlength () length is the length received
String info = new String (Data,0,datagrampacket.getlength ());
System. out. println ("Here is the message from the server, the client:--" +info);

/**
*  Responding to a client
*/
1, define the client's address, port number, data
Get Client IP Address
InetAddress inetaddress = datagrampacket.getaddress ();
Get Client port number
int port= datagrampacket.getport ();
Save the contents of the response to a byte array
byte []DATA2 = "Welcome!" ". GetBytes ();
2 Create a datagram that contains the data information for the response
Datagrampacket datagramPacket12 = new Datagrampacket (data2,data2.length,inetaddress,port);
3. Responding to clients
Datagramsocket.send (datagramPacket12);
4. Close Resources
Datagramsocket.close ();

}
}

Client

Import java.io.IOException;
Import java.net.*;

/**udpClient
* Created by Jim Calark on 2017/3/19.
*/
public class UdpClient {
public static void Main (string[] args) throws Unknownhostexception, socketexception,ioexception{
1. Define server address, port number, data
InetAddress inetaddress = inetaddress.Getbyname("localhost");
int port = 8800;
byte [] data = "User name: the most handsome; Password: 123". GetBytes ();
2. Create a datagram that contains the information sent
Datagrampacket datagrampacket = new Datagrampacket (data,data.length,inetaddress,port);
3. Create a Datagramsocket object
Datagramsocket datagramsocket = new Datagramsocket ();
4. Send datagrams to server side
Datagramsocket.send (Datagrampacket);

/**
* client receives server-side response information
*
*/
1. Create a datagram to receive server-side response data and save the data in a byte array
byte [] data2 = new byte[1024];
Datagrampacket datagramPacket1 =new datagrampacket (data2, data2.length);
2. Receiving server response data
Datagramsocket.receive (DATAGRAMPACKET1);
3. Read data
string reply = new string (Data2,0,datagrampacket1.getlength ());
System. out. println ("Here is the message from the client, server side:--" + reply);
4. Close Resources
Datagramsocket.close ();


}
}

Java socket based on UDP/IP protocol