Dns server and client in java

Hello!
Im trying to code a dns server and client in java.
It`s supposed to be a very simple one. The server should just resolve the query, started from the client.
Where can I find any code samples? It would really help me to get started.
Thank you very much!
Anne

Do you have some code ?

Similar Messages

Try to use one comupter as both server and client

Hello, everyone, I am just trying to use my own computer as both server and client to test some codes about networking. For example, use the sample code in java tutorial which is used to test Echo server(code is listed below). Is there anything I have to do to set my computer, such as set my hostname or something like that?
I am a pure newbie. And the purpose of this question is to test some code including socket on one PC without connect to internet.
I have tried to change the name "taranis" in the following code to the computer name of my own PC, but it doesn't work, and said: Couldn't get I/O for the connection to: (my computer name).
import java.io.*;
import java.net.*;
public class EchoClient {
public static void main(String[] args) throws IOException {
Socket echoSocket = null;
PrintWriter out = null;
BufferedReader in = null;
try {
echoSocket = new Socket("taranis", 7);
out = new PrintWriter(echoSocket.getOutputStream(), true);
in = new BufferedReader(new InputStreamReader(
echoSocket.getInputStream()));
} catch (UnknownHostException e) {
System.err.println("Don't know about host: taranis.");
System.exit(1);
} catch (IOException e) {
System.err.println("Couldn't get I/O for "
+ "the connection to: taranis.");
System.exit(1);
     BufferedReader stdIn = new BufferedReader(
new InputStreamReader(System.in));
     String userInput;
     while ((userInput = stdIn.readLine()) != null) {
     out.println(userInput);
     System.out.println("echo: " + in.readLine());
     out.close();
     in.close();
     stdIn.close();
     echoSocket.close();

Did you write the EchoServer and start it on your
machine, listening on port 7?
You can have the client and server running on the same
machine or different machines, but they have to be
separate pieces of software.
Write a separate EchoServer class that starts up and
listens on that port. Then start the EchoClient and
make the connection.
%yeah, I didn't wrote the EchoServer class. But I thought it is automaticly included and therefore has run once I start my computer.
If I write a EchoServer class, then how should I set the host name of the EchoClient, just simply change "taranis" to my computer name (change "echoSocket = new Socket("taranis", 7);" to echoSocket = new Socket("(my comptuer name)", 7);"?

Force CORBA server and client to localhost

Hi,
i have to run an omg corba server and client via orbd on a single machine with win xp. The machine is connected to the network, but this is not relevant for the corba communication.
I can now force the orbd to start at localhost. After starting server and client everything works well until disconnecting machine from network, because client and server are started at ip of network card.
How can i force the client and server to use a localhost port for corba communication (client and server)?
Hope anyone has an idea...
br
ralf
P.S.: If I start the applications after disconnecting network everthing works.

Resolved the problem myself.
The correct property is a java system property:
com.sun.CORBA.ORBServerHost=localhost
If you set this property in your application before instanciating an ORB, the orb will be forced to run on the set value (in this case localhost). If you do not set this property the ORB will be started at the IP of your network card if it is active (connected to the network)...

Connection fails if server and clients are in different subnets

Hello,
our Volume License Manager (v2.1) is running in another subnets than the clients (All machines are running under Windows XP-SP2 without Domains or ADS, just workgroups).
The server is in subnet A (192.168.42.0/24), all clients are located in another subnet B (192.168.50.0/24).
Routing is properly configured and is working fine, traffic to the specific hosts is not blocked by a firewall. We can ping every machine,
open telnet connections to the NILM, everything works.
But if the clients try to connect to the remote NILM (both local client NI License Manager and VLM port settings are correct) their connection attempt always
times out with error code "NILM10"
(I already read the mentioned KBs, no solution has helped so far). This is true if clients and server are separated.
For testing purposes, i plugged one client into the server's subnet (server's IP: 192.168.50.250, client 192.168.50.10)
and it worked perfectly. Is there a reason why server and client have to be on the same subnet or is it some other kind of problem that I am not aware of?
Thank you.
Thorsten

Hello Thorsten,
Did you add the server's domain to the client computer's DNS settings. To do this, complete the following steps on the client computer:
1. Open Local Area Network Settings from the Control Panel (Start»Control Panel»Network Connections»Local Area Connection)
2. Click the Properties button
3. Select Internet Protocol (TCP/IP) from the list of network components
4. Click the Properties button
5. Click the Advanced button
6. Change to the DNS tab
7. Ensure Append these DNS suffixes is selected
8. Click the Add button
9. Enter the domain suffix of the license server and click Add
10. Close any open dialog boxes, choosing OK and Close as necessary.
(http://digital.ni.com/public.nsf/allkb/3AAF37CD7B89A2CD86257070005A075A?OpenDocument)
Further you should check this KBs.
Why is My NI License Manager Slow or Not Responsive with a Configured Network Server on Another Domain?
http://digital.ni.com/public.nsf/allkb/27D6BD8116EF257A862572F2005C2181?OpenDocument
How Can I Access NI Volume License Manager from a Different Network or Behind a Firewall?
http://digital.ni.com/public.nsf/websearch/54E52C3F348B929786256DCD0056B19B?OpenDocument
Regards,
WolfgangZ

Data streaming between server and client does not complete

Using an ad-hoc app, data streaming between server
and client does not complete as it supposed to be.
The process runs well in solaris 5.8, however under 5.9
we have found the characters stream buffer length limitation
is around 900 to 950 characters (by default we are using 3072
characters).
Example:
- We are transfering HTML file, which will be displayed
in the App client, with buffer=3072, the HTML only displayed / transfered
as xxxxxxxx characters, but with buffer=900 the HTML is displayed properly,
in this case, the only problem that we have is the file transfer will
eventually longer than usual.
- There is another case, where we have to transfer information (data) as stream
to the client. A long data stream will not appear at all in the client.
Any ideas why the change between 5.8 and 5.9 woudl cause problems?
The current app-driver that we are using is compiled using Solaris 5.6,
if possible we would like to have use of a later version, which is compiled using Solaris 5.9, do you think this will probably solve our problem?
Thanks
Paul

Does this have anything to do with Java RMI? or with Java come to think of it?

MultiThreaded Server and Client connections query.

I have written a MultiThreaded Server to accept incoming client requests.
Multiple clients can connnect to this server and have a conversation.
I invoke the 'MultiServer' from the command line and then invoke 3 clients
from the command line.('Client').
c:> java MultiServer
c:> java Client
c:> java Client
c:> java Client
All the 3 clients now run in their own thread and send messages
to the server.
The problem I am facing is this:
When client1 connects to the server and sends a message to the server (with the server responding)
it works fine.Both Server and Client can exchange messages.
When client2 connects to the server and sends a message and when the server
responds with a message,the message does NOT go to client2,but goes to Client1
As Clients have their own thread to run,shouldnt the messages also be delivered to
individual clients
Am I missing something?
My Code
public class MultiServer {
    public static void main(String[] args) throws IOException {
        ServerSocket serverSocket = null;
        boolean listening = true;
        try {
            serverSocket = new ServerSocket(4444);
            System.out.println("MultiServer listening on Port 4444");
        } catch (IOException e) {
            System.err.println("Could not listen on port: 4444.");
            System.exit(-1);
        // Indefinite Loop.
        while (listening)
         new MultiServerThread(serverSocket.accept()).start();
        serverSocket.close();
public class MultiServerThread extends Thread {
    private Socket socket = null;
    public MultiServerThread(Socket socket) {
     super("MultiServerThread");
     this.socket = socket;
    public void run() {
     try {
         PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
         BufferedReader in = new BufferedReader(
                        new InputStreamReader(
                        socket.getInputStream()));
           BufferedReader stdInFromServer = new BufferedReader(new InputStreamReader(System.in));
        String fromTheClient,fromServer;
           fromServer = "Hi Client,How u doing? ";
        // Send a message from the Server.
           out.println(fromServer);
            while ((fromTheClient = in.readLine()) != null) {
             if (fromTheClient.equals("ByeServer"))
             break;
             // Display message received from Client.
             System.out.print("Client Response : ");
          System.out.println(fromTheClient);
             // Input reply from the Server.
             fromServer = stdInFromServer.readLine();
             out.println(fromServer);
             if (fromServer.equals("Bye."))
                break;
         out.close();
         in.close();
         socket.close();
     } catch (IOException e) {
         e.printStackTrace();
Client Code
===========
public class Client {
    public static void main(String[] args) throws IOException {
        Socket kkSocket = null;
        PrintWriter out = null;
        BufferedReader in = null;
        try {
            kkSocket = new Socket("localhost", 4444);
            out = new PrintWriter(kkSocket.getOutputStream(), true);
            in = new BufferedReader(new InputStreamReader(kkSocket.getInputStream()));
        } catch (UnknownHostException e) {
            System.err.println("Don't know about host: localhost.");
            System.exit(1);
        } catch (IOException e) {
            System.err.println("Couldn't get I/O for the connection to: localhost.");
            System.exit(1);
        BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));
        String fromServer;
        String fromUser;
        while ((fromServer = in.readLine()) != null) {
            System.out.println("Server: " + fromServer);
            if (fromServer.equals("Bye."))
                break;
                fromUser = stdIn.readLine();
         if (fromUser != null) {
                out.println(fromUser);
        out.close();
        in.close();
        stdIn.close();
        kkSocket.close();
}

Taking standard input for multiple threads from one console is quite unpredictable. I think the first client thread is waiting for input when you connect the second. You type something into your server window and since the first thread was waiting for input, it takes the input and sends it to client 1.

Can I put both RMI server and client in a same program

hi everybody...
I wanna know that can I use RMI server and client in a same program....My idea is like that I wanna use the same program for client and server....When I open my program, I can accept connection from other program and if I want to connect to others, I can also connect it. I expect you to understand my question. Here are the sample code for my program...
package Chat.Rmi;
import java.lang.*;
import java.util.*;
import java.rmi.*;
import javax.swing.*;
import java.net.*;
import java.rmi.server.*;
import java.rmi.registry.*;
public class netKitManager implements netKitInterface{
    public netKitManager(){
        try{
        reg = LocateRegistry.createRegistry(4242);
        reg.rebind("NetKitServer",this);
        }catch(RemoteException re){
    public void DirectConnect(String ip){
        try{
        netUser = (netKitInterface) Naming.lookup("rmi://"+ip+":4242/NetKitServer");
        JOptionPane.showMessageDialog(null,"Connection succeded!");
        }catch(NotBoundException nbe){
            JOptionPane.showMessageDialog(null,"There is no server at specified IP address!");
        }catch(MalformedURLException mue){
            JOptionPane.showMessageDialog(null,"IP adress may be wrong!");
        }catch(RemoteException re){
            JOptionPane.showMessageDialog(null,"Remote exception occured!");
    public void SendMessage(String msg){
        try{
        netUser.SetMessage(msg);
        }catch(RemoteException re){
    public void SetMessage(String msg) throws RemoteException{
        chatKit.SetMessage(msg);
    private netKitInterface netUser;
    private Hashtable netUserList;
    private Registry reg;
}

Yes it can be done. I have done it.

Serialize the object between Server and Client?

Hello friends,
What is the important to Serialize the object between server and client?
Thanks
tamilvanan

in which context ??
Anyways,checkout the below link and try to understand how do we convert Serializable Object's State to in Stream and send it over network.
http://java.sun.com/j2se/1.4.2/docs/guide/serialization/examples/index.html
Hope that might help :)
REGARDS,
RaHuL

Comprised of both server and client components

Hello all
We all consult an open source project and download freely the source code and the documentation for the server as a tarball. The well known open source project is Paragent which its platform is comprised of both server and client components written in Lisp, C++ and Java. just take a look and drop your suggestions.
Thanks for any help,
Bmora96

Huh?

Connection between server and client using thread

hi
i am new to java..i hav done a program to connect a server and client...but i hav not used threads in it..
so please tel me how to use threads and connect server and client..i tried it out not getin...i am havin thread exception...my program is as shown below
SERVER PRG:
import java.io.*;
import java.net.*;
public class Server{
String clientsen;
String serversen;
public void go(){
try{
     ServerSocket serverSock=new ServerSocket(6789);
     while(true) {
     Socket sock=serverSock.accept();
     BufferedReader inFromClient=new BufferedReader(new InputStreamReader(sock.getInputStream()));
     BufferedReader inFromuser=new BufferedReader(new InputStreamReader(System.in));
     DataOutputStream outToClient=new DataOutputStream(sock.getOutputStream());
     clientsen=inFromClient.readLine();
     System.out.println("From Client: "+clientsen);
     System.out.println("Reply mess to Client");
     serversen=inFromuser.readLine();
     outToClient.writeBytes(serversen+'\n');
} catch(IOException ex) {
     ex.printStackTrace();
public static void main(String[] args) {
     Server s = new Server();
     s.go();
     CLIENT PRG
import java.lang.*;
import java.util.*;
import java.io.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.net.*;
import java.lang.Thread;
import java.applet.Applet;
class Client1
public static void main(String argv[]) throws Exception
          String Sen;
          String modsen;
          BufferedReader inFromUser=new BufferedReader(new InputStreamReader(System.in));
Socket clientSocket=new Socket("192.168.1.2",6789);
          DataOutputStream outToServer=new DataOutputStream(clientSocket.getOutputStream());
          BufferedReader inFromServer=new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
          System.out.println("Enter the mess to be sent to server");
          Sen=inFromUser.readLine();
          outToServer.writeBytes(Sen + '\n');
          modsen=inFromServer.readLine();
          System.out.println("FROM SERVER: " +modsen);
          clientSocket.close();
please send me the solution code for my problem...

sorry for inconvenience...
SERVER PROGRAM
*import java.io.*;*
*import java.net.*;*
*public class MyRunnable implements Runnable*
   *public void run() {*
   *go();*
*public void go(){*
*try {*
    *String serversen;*
   *ServerSocket welcomeSocket=new ServerSocket(6789);*
   *while(true)*
*Socket connectionSocket=welcomeSocket.accept();*
*//BufferedReader inFromClient=new BufferedReader(new //InputStreamReader(connectionSocket.getInputStream()));*
*System.out.println("enter the mess to be sent to client");*
*BufferedReader inFromuser=new BufferedReader(new InputStreamReader(System.in));*
*DataOutputStream outToClient=new DataOutputStream(connectionSocket.getOutputStream());*
*//clientsen=inFromClient.readLine();*
*//System.out.println("From Client: "+clientsen);*
*//System.out.println("Reply mess to Client");*
*serversen=inFromuser.readLine();*
*outToClient.writeBytes(serversen+'\n');*
*} catch(IOException ex) {*
*        ex.printStackTrace();*
*class Server1{*
*public static void main(String argv[]) throws Exception*
     *Runnable threadJob=new MyRunnable();*
*Thread myThread=new Thread(threadJob);*
*myThread.start();*
*}*CLIENT PROGRAM
import java.io.*;
import java.net.*;
class Client2
public static void main(String argv[]) throws Exception
          //String Sen;
          String modsen;
          //BufferedReader inFromUser=new BufferedReader(new InputStreamReader(System.in));
Socket clientSocket=new Socket("192.168.1.2",6789);
          //DataOutputStream outToServer=new DataOutputStream(clientSocket.getOutputStream());
          BufferedReader inFromServer=new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
          //System.out.println("Enter the mess to be sent to server");
          //Sen=inFromUser.readLine();
     //     outToServer.writeBytes(Sen + '\n');
          modsen=inFromServer.readLine();
          System.out.println("FROM SERVER: " +modsen);
          clientSocket.close();
this is the code which i hav used using thread but i am gwetin error..ts is the error
Exception in thread "main" java.lang.NoSuchMethodError : Main

Problems with games server and client

Hi! I am making an MMORPG game and I have problems with the server and client connection.
I can connect to the server, but when a second player does, the server console tells me this:
java.net.SocketException: Connection reset
After that, all clients disconnect.
Which is the problem?
How can I solve it?
Thank you so much

Here is how my sever work. I took some of this code from a book called Killer Programming Games in Java. If you google for it, you will find it for sure.
TourGroup tg = new TourGroup(); // this object stores information about all clients connected to the server
    try {
      ServerSocket serverSock = new ServerSocket(PORT);
      Socket clientSock;
      while (true) {
        System.out.println("Waiting for a client...");
        clientSock = serverSock.accept();
        new TourServerHandler(clientSock, tg).start(); // this is the thread that monitors each client
    catch(Exception e)
    { System.out.println(e); }
} This is some code of TourServerHandler
public TourServerHandler(Socket s, TourGroup tg)
    this.tg = tg;
    clientSock = s;
    name= "?";
    cliAddr = clientSock.getInetAddress().getHostAddress();
    port = clientSock.getPort();
    System.out.println("Client connection from (" +
                 cliAddr + ", " + port + ")");
public void run()
// process messages from the client
    try {
      // Get I/O streams from the socket
      BufferedReader in = new BufferedReader(
   new InputStreamReader( clientSock.getInputStream() ) );
      PrintWriter out =
new PrintWriter( clientSock.getOutputStream(), true );
// and here goes the rest... The TourServerHandler thread uses this code to send messages:
tg.broadcast(msg); tg.broadcast works like this:
synchronized public void broadcast(String cliAddr, int port, String msg)
// broadcast to everyone but original msg sender
    TouristInfo c; // this object stores info about the client
    for(int i=0; i < tourPeople.size(); i++) {
      c = (TouristInfo) tourPeople.get(i);
        c.sendMessage(msg);
} This is the error part
public void sendMessage(String msg)
PrintWriter out;
    out.println(msg);
      System.out.println("OK");
} I can't find any error but I still get that Connection reset exception...

TS1843 I am getting the following error messages- No DNS Server and Double SAT. Can anyone walk me through a fix?

Airport Express- No internet connection. I am getting the following error messages- No DNS Server and Double SAT. Can anyone walk me through a fix

Try putting these numbers in Network>TCP/IP>DNS Servers, for the Interface you connect with...
208.67.222.222
208.67.220.220
Then Apply. For 10.5/10.6 Network, highlight Interface>Advanced button>DNS tab>little + icon.
Might also put them in the Airport Express, no idea what Double SAT is!?

I am using server and client systems when i am trying to open the browser in two or more machines it says that firefox is already running, i want to open the browser in all machines simeltaniously

I am using server and clients machines in my office, here i want to open browsers in all systems simultaneously but i am unable open the browser, when i am trying to open the browser in the second machine it says that firefox is already open... pls. solve this problem
Thank you

You can't open one Profile more than once. You need a separate Profile for each browser on each PC that you open.
https://support.mozilla.com/en-US/kb/Profiles

Time sync between server and client

Hi guys,
I have written a chess server and client. My next step is to implement a clock which will be used in timed games, however, I am not sure of the best solution. I can't think of a reliable method to keep the client's time in sync with the servers because the event latency varies between individual events and clients.
My first idea was to send a 'tick' event every second but I dont think this the best solution. I have seen many applet based clients which have timers, such as Yahoo chess.
I know this question is a little vague, I can give more detail if needed.
Thanks,
Alex

To prevent client-side cheating, the server should keep the
"official" clock. Every so often (perhaps when a move gets made?),
notify both clients of the official time. Clients count seconds from
that official time.
This is a suboptimal solution because it leaves clients vulnerable
to network lag. I can't think of any other solution that doesn't give
clients some responsibility for tracking time, though, and that's a
big security hole.
If you're willing to open that hole, have each client report back to
the server the elapsed local time from when they recieved the
last move to when they made their move. Then update the other
client's clock accordingly.

Redundant folders created in root of C drive of server and Client . I want to stop the same and want to automatically delete them from server and client .

Redundant folders created in root of C drive of server and Client . I want to stop the same and want to automatically delete them from server and client .
Please let me know the solution to delete them not manually . It should not create automatically .Is there a way we can change the path of creation.
Is there a way that once the folfer is create should be automatically deleted once the task is done.
Redundant folders are created in the root of my C drive all the time,
folder names look like:
09b0508d0bd2dbd70523
56f51b81c1462bb378009ee4d5ed03
02afe4378371907aca40ab

This is a duplicate of
http://social.technet.microsoft.com/Forums/systemcenter/en-US/ae99c2d0-8dea-4c5e-8a79-17e08e9e5de4/sccm-2012-issue-folders-with-long-guid-are-created-in-c-drive?forum=winservergen#ae99c2d0-8dea-4c5e-8a79-17e08e9e5de4
Jason | http://blog.configmgrftw.com

Dns server and client in java

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