Thread: Problem in UDS client,server program

Hi,
I have this problem: My program should be to do this, client send datagram to server and server send datagram to another client. But My program send datagram to server server recived but server doesn´t send to another client. My server code:

try { 
DatagramSocket server = new DatagramSocket(5000); 
byte[] poslana = new byte[256]; 
byte[] prijata = new byte[256]; 
byte[] preposi = new byte[256]; 
byte ip[] = { Network.ip(127), Network.ip(0), Network.ip(0), Network.ip(1)}; 
InetAddress kolo = InetAddress.getByAddress(ip); 
while (true) 
{ 
DatagramPacket prijatyPaket = new DatagramPacket(prijata,prijata.length); 
server.receive(prijatyPaket); 
String prepos = new String(prijatyPaket.getData()); 
preposi = prepos.getBytes(); 
InetAddress adresa = InetAddress.getByAddress(ip); 
DatagramPacket odeslat = new DatagramPacket(preposi,preposi.length,adresa,5000); 
server.send(odeslat);

This should be to do.Client send text and server send back. I am sory my English is not good. I hope you understand me.
Thank you for your advice.

I trust that 127.0.0.1 is the address of your router, in which you will need to set up port forwarding etc, so that when it recieves something on port 5000 it will forward it to the required PC on the specified port. I think you will find this is not a Java problem but a technical problem

Chris

I don´t think so. Becouse I work with only localhost. 127.0.0.1=localhost . My router has got IP address 192.168.1.100.

Good point, What is the code that is receiving the message?

This code on side server recive and send:

DatagramPacket prijatyPaket = new DatagramPacket(prijata,prijata.length); 
server.receive(prijatyPaket); //recive package
String prepos = new String(prijatyPaket.getData()); //get data from package 
preposi = prepos.getBytes(); //assign data from package to preposi
InetAddress adresa = InetAddress.getByAddress(ip); //IP address client (localhost)
DatagramPacket odeslat = new DatagramPacket(preposi,preposi.length,adresa,5000);//creating new datagram 
server.send(odeslat);//send datagram to client

And this is code client:

package messenger;
 
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
import java.util.logging.Level;
import java.util.logging.Logger;
 
/**
 *
 * @author Lolek
 */
public class Main {
 
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        while(true)
        {
            try {               
                BufferedReader cteni = new BufferedReader(new InputStreamReader(System.in)); 
                DatagramSocket klient = new DatagramSocket();
                try {
                    InetAddress lokalni = InetAddress.getByName("localhost");                 
                    byte[] poslana = new byte[256];
                    byte[] prijata = new byte[256];
                    String k = cteni.readLine();
                    poslana = k.getBytes();
                    DatagramPacket odesilanyPaket = new DatagramPacket(poslana, poslana.length,lokalni,5000);
                    klient.send(odesilanyPaket);
                    DatagramPacket prijatyPaket = new DatagramPacket(prijata,prijata.length);
                    klient.receive(prijatyPaket);
                    String prijataData = new String(prijatyPaket.getData());
                    System.out.println("Od serveru"+prijataData);
 
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }                            
            } catch (SocketException ex) {
                Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
            }
 
 
 
 
 
 
        }
 
 
 
 
    }
 
}

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
 
package msnserver;
 
 
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.logging.Level;
import java.util.logging.Logger;
 
/**
 *
 * @author Lolek
 */
 
public class Main {
 
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
          try {
 
            DatagramSocket server = new DatagramSocket(5000);//vytvoreni server soketu ktery nasloucha na portu 5000
            //BufferedReader cteni = new BufferedReader(new InputStreamReader(System.in));////cteni z klavesnice(vytvoreni proudu dat)
            byte[] poslana = new byte[256];//vytvoreni 256 bytoveho pole pro posilana data
            byte[] prijata = new byte[256];//vytvoreni 256 bytoveho pole pro prijata data
            byte[] preposi = new byte[256];            
            byte ip[] = { Network.ip(127), Network.ip(0), Network.ip(0), Network.ip(1)};
           InetAddress kolo = InetAddress.getByAddress(ip);
 
 
 
            //String ukonceni = "/q";
            //String kOdeslani;           
            while (true)                
            {
            DatagramPacket prijatyPaket = new DatagramPacket(prijata,prijata.length);// zaobaleni pole bajtu k prijmu
            server.receive(prijatyPaket);//prijmuti paketu  
            String prepos = new String(prijatyPaket.getData());              
            preposi = prepos.getBytes();            
            InetAddress adresa = InetAddress.getByAddress(ip);
            DatagramPacket odeslat = new DatagramPacket(preposi,preposi.length,adresa,5000);
            server.send(odeslat);                       
            //server.send(prijatyPaket);
            //String prijataData = new String(prijatyPaket.getData());//ziskani dat z prijmuteho paketu a prirazeni je do s          
            //System.out.println("Od klientu:"+prijataData);//vypis prijatych dat
            //InetAddress IPKlienta = prijatyPaket.getAddress();//Ziskani IP adresy klienta a prirazeni do IPKlient
            //int port = prijatyPaket.getPort();//Ziskani portu klienta a prirazeni do port
            //kOdeslani = cteni.readLine();//cteni dat po radcich
            //poslana = kOdeslani.getBytes();//prirazani dat do poslana
            //DatagramPacket odesilanyPaket = new DatagramPacket(poslana,poslana.length,IPKlienta,port);
            //server.send(odesilanyPaket);
            //if (kOdeslani.equals(ukonceni))
            //{
            //    System.exit(0);
            //}
 
            }            
        } catch (IOException ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        }    
 
    }
 
}

and class network

package msnserver;
 
/**
 *
 * @author Lolek
 */
class Network {
 
public static byte ip(int i) {
return (byte) ((i > 127) ? i - 256 : i);
}
}

Ï solved it. Thank you. Bad client port.