Develop Reference

Java StreamCorrupted when connecting more than one Client to Server

Explanation
I'm currently trying to create a Multiplayer Game with Java where up to five Players can play together.
The problem is that when I'm trying to connect multiple Clients to my Server I get an Exception and the Server doesn't work anymore.
With one Client at a time, everything works fine.
So what I need is a Server that can handle up to five players at a time and the clients should always get some new game data from the Server
every few seconds (Connected Players, etc.).
The "Game data" in the code below is the String I'm sending through the Object Stream.
Normally I would send an Object which has all the game data, but with the String, I get the same problem.
I'm struggling with the problem that only one Client can connect without any errors occurring for some days now and I didn't find a solution to my problem.
I saw that there are things like java.nio or the ExecutorService, but I didn't really understand those that much, so I don't know if they can help.
I have made a smaller program that simulates the same problem I get with my bigger program.
To Start the Server, you need to Start the GameMultiPlayerCreate.java Class, and for the Client, the Client.java class.
I'm new to Sockets so if something is unnecessary or if something can be made better please let me know.
So the Error I'm getting when I connect two or more Clients is:
java.io.StreamCorruptedException: invalid stream header: 00050131
at java.io.ObjectInputStream.readStreamHeader(Unknown Source)
at java.io.ObjectInputStream.<init>(Unknown Source)
at Server.waitForData(Server.java:89) //I highlighted that in the code with a comment
at Server.loopWaitForData(Server.java:49)
at Server.run(Server.java:34)
at java.lang.Thread.run(Unknown Source)
Code
GameMultiPlayerCreate.java: Should start the Server threads if a Client connects
public class GameMultiPlayerCreate {
ServerSocket socketServer = null;
static String settingIp = "localhost";
static String settingPort = "22222";
static byte settingPlayers = 5;
public static int connectedPlayers = 0;
public static void main(String[] args) {
try {
GameMultiPlayerCreate objGameMultiPlayerCreate = new GameMultiPlayerCreate();
objGameMultiPlayerCreate.createServer();
} catch (NumberFormatException | IOException | InterruptedException e) {
e.printStackTrace();
}
}
public void createServer() throws NumberFormatException, UnknownHostException, IOException, InterruptedException {
while (connectedPlayers < settingPlayers) {
socketServer = new ServerSocket(Integer.parseInt(settingPort), 8, InetAddress.getByName(settingIp));
System.out.println("Server is waiting for connection...");
Socket socket = socketServer.accept();
new Thread(new Server(socket)).start();
Thread.sleep(5000);
socketServer.close();
}
}
}
Server.java: This is the Class of which a new Thread should be created for each connected Client (Client Handler)
public class Server implements Runnable {
protected static Socket socket = null;
private int loops;
private int maxLoops = 10;
private int timeout = 10000;
protected static boolean killThread = false;
private boolean authenticated = true; //true for testing
protected static String ip;
protected static int port;
public Server(Socket socket) throws IOException {
Server.socket = socket;
}
public void run() {
try {
socket.setSoTimeout(timeout);
} catch (SocketException e) {
System.out.println("Error while trying to set Socket timeout. ");
System.out.println("Closing Thread..." + Thread.currentThread());
disconnectClient();
}
if (!killThread) {
GameMultiPlayerCreate.connectedPlayers = GameMultiPlayerCreate.connectedPlayers + 1;
loopWaitForData();
}
}
private void disconnectClient() {
System.out.println("Kicking Client... " + Thread.currentThread());
killThread = true;
GameMultiPlayerCreate.connectedPlayers = GameMultiPlayerCreate.connectedPlayers - 1;
}
public void loopWaitForData() {
while (!killThread) {
System.out.println(maxLoops + ", " + loops);
if (maxLoops - loops > 0) {
try {
waitForData();
} catch (SocketTimeoutException e) {
System.out.println("Error occurred while waiting for Data. Thread disconnected? Sending reminder. " + Thread.currentThread());
if (!authenticated) {
System.out.println("Kicking Client: Not authenticated");
disconnectClient();
} else {
commandReminder();
}
} catch (ClassNotFoundException | IOException e) {
loops = loops + 1;
System.out.println("Error occurred while waiting for Data. Waiting for more Data. " + Thread.currentThread());
e.printStackTrace();
loopWaitForData();
}
} else if (maxLoops - loops == 0) {
System.out.println("Error occurred while waiting for Data. Maximum trys reached. Disbanding connection. " + Thread.currentThread());
disconnectClient();
loops = loops + 1;
} else {
System.out.println("Closing Thread..." + Thread.currentThread());
disconnectClient();
}
}
}
private void commandReminder() {
System.out.println("Reminder");
try {
String code = new String("0");
ObjectOutputStream outputObject = new ObjectOutputStream(Server.socket.getOutputStream());
outputObject.writeObject(code);
} catch (IOException e) {
System.out.println("Error occurred while trying to authenticate Client: " + e + " in " + Thread.currentThread());
}
}
public void waitForData() throws IOException, ClassNotFoundException {
String code;
System.out.println("Waiting for Data...");
//Next line is where the error occurres
ObjectInputStream inputObject = new ObjectInputStream(socket.getInputStream());
while ((code = (String) inputObject.readObject()) != null) {
System.out.println("Received Data...");
System.out.println("Input received: " + code);
return;
}
}
}
Client.java: This is the Client
public class Client {
public static Socket socket = new Socket();
private int loops = 0;
private int maxLoops = 10;
private static boolean killThread = false;
private String ip;
private int port;
public Client(String receivedIp, String receivedPort) {
ip = receivedIp;
port = Integer.parseInt(receivedPort);
try {
System.out.println("Trying to connect to Server...");
socket.connect(new InetSocketAddress(ip, port));
System.out.println("Connected!");
} catch (IOException e) {
System.out.println("Error occurred while trying to connect to Server.");
}
loopWaitForData();
}
public static void main(String[] args) {
#SuppressWarnings("unused")
Client objClient = new Client("localhost", "22222");
}
public void loopWaitForData() {
while (!killThread) {
System.out.println(maxLoops + ", " + loops);
if (maxLoops - loops > 0) {
try {
waitForData();
} catch (IOException | ClassNotFoundException e) {
loops = loops + 1;
try {
Thread.sleep(2000);
} catch (InterruptedException e1) {
}
System.out.println("Error occurred while waiting for Data. Waiting for more Data. " + Thread.currentThread());
e.printStackTrace();
loopWaitForData();
}
} else if (maxLoops - loops == 0){
System.out.println("Error occurred while waiting for Data. Maximum trys reached. Disbanding connection. " + Thread.currentThread());
try {
socket.close();
} catch (IOException e) {
System.out.println("Failed to close Socket " + Thread.currentThread());
}
loops = loops + 1;
} else {
System.out.println("Closing Thread..." + Thread.currentThread());
killThread = true;
}
}
}
public void waitForData() throws IOException, ClassNotFoundException {
InputStream input = socket.getInputStream();
ObjectInputStream inputObject = new ObjectInputStream(input);
String code;
System.out.println("Waiting for Data...");
while ((code = (String) inputObject.readObject()) != null) {
System.out.println("Received Data...");
System.out.println("Input received: " + code);
answer();
return;
}
}
private void answer() {
try {
String code = new String("1");
ObjectOutputStream outputObject = new ObjectOutputStream(socket.getOutputStream());
outputObject.writeObject(code);
} catch (IOException e) {
System.out.println("Error occurred while trying to answer: " + e + " in " + Thread.currentThread());
}
}
}

How can I maintain two client sockets together using java

I want to create a class that contain two socket I.e socket for client1 and socket for client 2 so that they can chat together.
How can I achieve this.When i run above code i am getting stream corrupted exception .
My chat is not working. Can someone help me out ?
Here is my code .
This is client code for making socket request
Client.java
package customChat;
import java.net.*;
import java.io.*;
import java.util.*;
public class Client
{
private String notif = " *** ";
private ObjectInputStream sInput;
private ObjectOutputStream sOutput;
private Socket socket;
private String server, username;
private int port;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
private RemoteAccess access;
Client(String server, int port,RemoteAccess access ) {
this.server = server;
this.port = port;
this.access = access;
}
public boolean start()
{
try
{
socket = new Socket(server, port);
}
catch(Exception ec) {
display("Error connectiong to server:" + ec);
return false;
}
String msg = "Connection accepted " + socket.getInetAddress() + ":" + socket.getPort();
display(msg);
try
{
sInput= new ObjectInputStream(socket.getInputStream());
sOutput = new ObjectOutputStream(socket.getOutputStream());
}
catch (IOException eIO) {
eIO.printStackTrace();
display("Exception creating new Input/output Streams in client: " + eIO);
return false;
}
new ListenFromServer().start();
try
{
sOutput.writeObject(access);
}
catch (IOException eIO) {
display("Exception doing login : " + eIO);
//disconnect();
return false;
}
return true;
}
private void display(String msg)
{
System.out.println(msg);
}
void sendMessage(RemoteAccess msg)
{
try
{
System.out.println("I am writing for :"+msg.getTo()+": msg "+msg.getMsg());
sOutput.writeObject(msg);
}
catch(IOException e) {
display("Exception writing to server: " + e);
}
}
private void disconnect() {
try {
if(sInput != null) sInput.close();
}
catch(Exception e)
{
e.printStackTrace();
}
try {
if(sOutput != null) sOutput.close();
}
catch(Exception e) {
e.printStackTrace();
}
try{
if(socket != null) socket.close();
}
catch(Exception e) {
e.printStackTrace();
}
}
public static void sendFile()
{
int portNumber = 1502;
String serverAddress = "localhost";
Scanner scan = new Scanner(System.in);
System.out.println("Enter from ");
long from = scan.nextLong();
System.out.println("Enter to");
long to = scan.nextLong();
RemoteAccess access = new RemoteAccess(to,from,"hello");
Client client = new Client(serverAddress, portNumber,access);
if(!client.start())
return;
while(true)
{
System.out.println("Please enter msg:");
System.out.print("> ");
// read message from user
String msg = scan.nextLine();
System.out.println("Sending message");
client.sendMessage(new RemoteAccess(to,from,msg));
}
}
public static void main(String[] args)
{
sendFile();
}
class ListenFromServer extends Thread {
public void run()
{
System.out.println("i am in run method");
while(true)
{
System.out.println("i am in run method 2");
try
{
System.out.println("i am in run method 3");
RemoteAccess access = (RemoteAccess) sInput.readObject();
System.out.println("Message read by:"+access.getFrom());
if(access !=null)
{
System.out.println("Message is :"+access.getFrom());
}
}
catch(IOException e)
{
e.printStackTrace();
System.out.println("Excepion caught while listening from server :"+e);
display(notif + "Server has closed the connection: " + e + notif);
break;
}
catch(ClassNotFoundException e2) {
e2.printStackTrace();
}
}
}
}
}
Server.java
package customChat;
import java.io.*;
import java.net.*;
import java.text.SimpleDateFormat;
import java.util.*;
public class Server {
private SimpleDateFormat sdf;
private int port;
private boolean keepGoing;
private String notif = " *** ";
public static ArrayList<ClientThread> al;
public Server(int port)
{
this.port = port;
sdf = new SimpleDateFormat("HH:mm:ss");
al = new ArrayList<ClientThread>();
}
public void start() {
keepGoing = true;
try
{
ServerSocket serverSocket = new ServerSocket(port);
while(keepGoing)
{
display("Server waiting for Clients on port " + port + ".");
Socket socket = serverSocket.accept();
if(!keepGoing)
break;
ClientThread t = new ClientThread(socket);
Thread t1 =new Thread(t);
System.out.println("Connection initiated by:"+t.access.getFrom());
Server.al.add(t);
t1.start();
}
/*try {
serverSocket.close();
for(int i = 0; i < Server.al.size(); ++i) {
ClientThread tc = Server.al.get(i);
try {
tc.sInput.close();
tc.sOutput.close();
tc.socket.close();
}
catch(IOException ioE) {
ioE.printStackTrace();
}
}
}
catch(Exception e)
{
display("Exception closing the server and clients: " + e);
}*/
}
catch (IOException e) {
String msg = sdf.format(new Date()) + " Exception on new ServerSocket: " + e + "\n";
display(msg);
}
}
/*protected void stop() {
keepGoing = false;
try {
new Socket("localhost", port);
}
catch(Exception e) {
}
}*/
// Display an event to the console
private void display(String msg) {
String time = sdf.format(new Date()) + " " + msg;
System.out.println(time);
}
public static void main(String[] args) {
// start server on port 1500 unless a PortNumber is specified
int portNumber = 1502;
// create a server object and start it
Server server = new Server(portNumber);
server.start();
}
}
ClientThread.java
package customChat;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Date;
/*class ListClient
{
public static ArrayList<ClientThread> al=new ArrayList<>();;
}*/
public class ClientThread implements Runnable {
Socket socket;
ObjectInputStream sInput;
ObjectOutputStream sOutput;
String date;
RemoteAccess access;
public RemoteAccess getAccess() {
return access;
}
public void setAccess(RemoteAccess access) {
this.access = access;
}
// Constructor
ClientThread(Socket socket) {
this.socket = socket;
System.out.println("Thread trying to create Object Input/Output Streams");
try
{
sOutput = new ObjectOutputStream(socket.getOutputStream());
sInput = new ObjectInputStream(socket.getInputStream());
System.out.println("CT input Stream :"+sInput);
access = (RemoteAccess) sInput.readObject();
System.out.println(access.getFrom() +"Joined the chat room");
}
catch (IOException e)
{
e.printStackTrace();
System.out.println("Exception creating new Input/output Streams: " + e);
return;
}
catch (ClassNotFoundException e)
{
e.printStackTrace();
}
date = new Date().toString() + "\n";
}
/*private void close() {
try {
if(sOutput != null) sOutput.close();
}
catch(Exception e) {
e.printStackTrace();
}
try {
if(sInput != null) sInput.close();
}
catch(Exception e) {
e.printStackTrace();
};
try {
if(socket != null) socket.close();
}
catch (Exception e) {
e.printStackTrace();
}
}
*/
#Override
public void run()
{
System.out.println("List size is :"+Server.al.size());
for(int i=0;i<Server.al.size();i++)
{
try {
System.out.println("Socket input Stream :"+Server.al.get(i).socket.getInputStream());
System.out.println("Socket :"+socket.getInputStream());
} catch (IOException e) {
e.printStackTrace();
}
if(Server.al.get(i).access.getFrom()==access.getTo())
{
System.out.println("I am in if part :"+Server.al.get(i).access.getFrom() +"compare to :"+access.getTo());
PairHandler t = null;
try {
t = new PairHandler(access.getTo(),Server.al.get(i).socket,Server.al.get(i).socket.getInputStream(),Server.al.get(i).socket.getOutputStream(),socket.getOutputStream(),socket.getInputStream(),socket);
} catch (IOException e) {
e.printStackTrace();
}
Thread t1 = new Thread(t);
System.out.println("Connection initiated by in CT:"+access.getFrom());
t1.start();
}
else{
System.out.println("I am in else in CT");
}
}
}
}
PairHandler.java
This is where i am using two client socket
package customChat;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.net.Socket;
public class PairHandler implements Runnable
{
long stbId;
Socket tvsocket;
ObjectInputStream tvsInput;
ObjectOutputStream tvsOutput;
Socket dtsocket;
ObjectInputStream dtsInput;
ObjectOutputStream dtsOutput;
PairHandler(long stbId,Socket tvsocket,Socket dtsocket)
{
this.stbId = stbId;
this.tvsocket = tvsocket;
this.dtsocket = dtsocket;
try
{
tvsOutput = new ObjectOutputStream(tvsocket.getOutputStream());
dtsOutput = new ObjectOutputStream(dtsocket.getOutputStream());
System.out.println("DT output Stream is :"+dtsOutput);
System.out.println("Tv outPut Stream is :"+tvsOutput);
System.out.println("RH input Stream :"+tvsocket.getInputStream());
tvsInput = new ObjectInputStream(tvsocket.getInputStream());
System.out.println("Tv input Stream is :"+tvsInput);
dtsInput = new ObjectInputStream(dtsocket.getInputStream());
System.out.println("DT input Stream is :"+dtsInput);
}
catch (IOException e)
{
e.printStackTrace();
System.out.println("Exception creating in Pair Handler new Input/output Streams: " + e);
return;
}
}
public PairHandler(long to, Socket socket, InputStream inputStream, OutputStream outputStream,
OutputStream outputStream2, InputStream inputStream2, Socket socket2) {
stbId = to;
tvsocket = socket;
dtsocket = socket2;
try{
tvsOutput = new ObjectOutputStream(outputStream);
dtsOutput = new ObjectOutputStream(outputStream2);
System.out.println("DT output Stream is :"+dtsOutput);
System.out.println("Tv input Stream is :"+socket.getInputStream());
System.out.println("DT input Stream is :"+socket2.getInputStream());
tvsInput = new ObjectInputStream(socket2.getInputStream());
System.out.println("Tv input Stream is 2 :"+tvsInput);
dtsInput = new ObjectInputStream(socket2.getInputStream());
System.out.println("DT input Stream is :"+dtsInput);
System.out.println("Tv input Stream is :"+tvsInput);
// TODO Auto-generated constructor stub
}
catch (IOException e)
{
System.out.println("Exception in PH");
e.printStackTrace();
}
}
#Override
public void run()
{
try
{
//dtsInput = new ObjectInputStream(dtsocket.getInputStream());
System.out.println("DT socket :"+dtsInput);
if(dtsInput!=null){
RemoteAccess dtMsg = (RemoteAccess) dtsInput.readObject();
if(dtMsg !=null){
// write to tvscoket
System.out.println("I am here in Pair Handler");
sendTOTv(dtMsg);
}
}
// tvsInput = new ObjectInputStream(tvsocket.getInputStream());
System.out.println("TV socket :"+tvsInput);
if(tvsInput!=null){
RemoteAccess tvmsg = (RemoteAccess) tvsInput.readObject();
if(tvmsg !=null){
// write to dtsocket
sendToDT(tvmsg);
}
}
}
catch (IOException e)
{
e.printStackTrace();
System.out.println("Exception found while msg");
}
catch(ClassNotFoundException e2) {
e2.printStackTrace();
}
}
private void sendToDT(RemoteAccess tvmsg) {
// TODO Auto-generated method stub
// if Client is still connected send the message to it
if(!dtsocket.isConnected())
{
closeDtSocket();
}
try {
dtsOutput.writeObject(tvmsg);
}
catch(IOException e) {
System.out.println("Failed to deliver msg");
}
}
private void closeDtSocket() {
try {
if(dtsOutput != null) dtsOutput.close();
}
catch(Exception e) {
e.printStackTrace();
}
try {
if(dtsInput != null) dtsInput.close();
}
catch(Exception e) {
e.printStackTrace();
};
try {
if(dtsocket != null) dtsocket.close();
}
catch (Exception e) {
e.printStackTrace();
}
}
private void closeTvSocket() {
try {
if(tvsOutput != null) tvsOutput.close();
}
catch(Exception e) {
e.printStackTrace();
}
try {
if(tvsInput != null) tvsInput.close();
}
catch(Exception e) {
e.printStackTrace();
};
try {
if(tvsocket != null) tvsocket.close();
}
catch (Exception e) {
e.printStackTrace();
}
}
private void sendTOTv(RemoteAccess dtMsg) {
// TODO Auto-generated method stub
if(!tvsocket.isConnected())
{
closeTvSocket();
}
try {
tvsOutput.writeObject(dtMsg);
}
catch(IOException e) {
System.out.println("Failed to deliver msg");
}
}
}
RemoteAccess.java
package customChat;
import java.io.File;
import java.io.Serializable;
class RemoteAccess implements Serializable {
private static final long serialVersionUID = 1L;
private long to;
private long from;
private File file;
private String msg;
private int x ;
private int y;
public int getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
public int getY() {
return y;
}
public void setY(int y) {
this.y = y;
}
public String getMsg() {
return msg;
}
public void setMsg(String msg) {
this.msg = msg;
}
RemoteAccess(){
}
RemoteAccess(long to,long from)
{
this.to=to;
this.from=from;
}
RemoteAccess(long to,long from,File file)
{
this.to=to;
this.from=from;
this.file=file;
}
RemoteAccess(long to,long from,int x,int y)
{
this.to=to;
this.from=from;
this.x=x;
this.y=y;
}
RemoteAccess(long to,long from,String msg)
{
this.to=to;
this.from=from;
this.msg=msg;
}
public File getFile() {
return file;
}
public void setFile(File file) {
this.file = file;
}
public long getTo() {
return to;
}
public void setTo(long to) {
this.to = to;
}
public long getFrom() {
return from;
}
public void setFrom(long from) {
this.from = from;
}
}

I supposed you want to customize client1 and client2. So you should create a class for each one :
public class Client1 extends Socket {
public Client1() {
super();
}
//Add stuff to customize
}
public class Client2 extends Socket {
public Client2() {
super();
}
//Add stuff to customize
}
Then create your class that contains your two sockets :
public class ClientDialog {
private Client1 client1;
private Client2 client2;
public ClientDialog() {
client1 = new Client1();
client2 = new Client1();
}
//Dialog between client
}

How to stop() Thread when it created on server side for client in java

when client leave the server connection how can i stop the Thread of server which is create for the communication between client and server and please tell me how can i send a single client message to all clients which are connected with that server thanks in advance :).
ChatServer.java
import java.net.*;
import java.io.*;
public class ChatServer implements Runnable
{
private ServerSocket server = null;
private Thread thread = null;
private ChatServerThread client = null;
public ChatServer(int port)
{
try
{ System.out.println("Binding to port " + port + ", please wait ...");
server = new ServerSocket(port);
System.out.println("Server started: " + server);
start();
}
catch(IOException ioe)
{ System.out.println(ioe); }
}
public void run()
{
while (thread != null)
{
try
{ System.out.println("Waiting for a client ...");
addThread(server.accept());
}
catch(IOException ie)
{ System.out.println("Acceptance Error: " + ie); }
}
}
public void addThread(Socket socket)
{ System.out.println("Client accepted: " + socket);
client = new ChatServerThread(this, socket);
try
{ client.open();
client.start();
}
catch(IOException ioe)
{ System.out.println("Error opening thread: " + ioe); }
}
public void start()
{ if (thread == null)
{ thread = new Thread(this);
thread.start();
}
}
public void stop()
{ if (thread != null)
{ thread.stop();
thread = null;
}
}
public static void main(String args[])
{ ChatServer server = null;
int x=2111;
if (x<1)
System.out.println("Usage: java ChatServer port");
else
server = new ChatServer(x);
}
}
ChatServerThread
import java.net.*;
import java.io.*;
public class ChatServerThread extends Thread
{ private Socket socket = null;
private ChatServer server = null;
private int ID = -1;
private DataInputStream streamIn = null;
public ChatServerThread(ChatServer _server, Socket _socket)
{ server = _server; socket = _socket; ID = socket.getPort();
}
public void run()
{ System.out.println("Server Thread " + ID + " running."+Thread.activeCount());
while (true)
{ try
{ System.out.println(streamIn.readUTF());
}
catch(IOException ioe) { }
}
}
public void open() throws IOException
{ streamIn = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
}
public void close() throws IOException
{
if (socket != null) socket.close();
if (streamIn != null) streamIn.close();
}
}

In ChatServerThread:
public void run()
try {
// thread code
} catch(InterruptedException e) {
Thread.currentThread().interrupt();
} finally {
// cleanup code, if required
}
}
and in ChatServer:
public void stop() {
if (thread != null) {
thread.interrupt();
thread = null;
}
}
This won't stop the thread, but it signals the thread to stop what it's doing - it might or might not stop right then, or even at all, depending on what code the thread is currently executing.

multithreaded server, loop is working only once

I have problem with my multhreaded server for bridge auction. The topic of it is less important, all I need to do so far is to make the loop inside the run method work for more than only one "lap". I mean my loop is working for each client only once and then It stopped, but I can't solve this problem. It should work all the time and after sequence of players N-> E-> S-> W-> it start another lap from player N, but now it just stand still...
Check my code:
package serwer;
import java.io.*;
import java.net.*;
import java.util.*;
import java.util.logging.*;
public class Serwer {
public static void main(String[] args) throws Exception {
System.out.println("Started server to the bridge auction");
int conCount = 0;
ServerSocket serwer = new ServerSocket(9898);
ArrayList<connection> connections = new ArrayList<connection>(){};
try {
//only 4 players are allowed to play bridge in one table
while (connections.size() < 4) {
connection p = new connection(serwer.accept(), conCount++);
connections.add(p);
connections.get(conCount-1).start();
}
} finally {
serwer.close();
}
}
/**
* static class responsible for the connection in multithreaded server
*/
static class connection extends Thread {
private Socket socket;
private int conCount;
private static int counter = 0;
private final String[] Players;
private String stringOnServer = "0";
private int stake = 1;
public connection(Socket socket, int conCount) {
this.Players = new String[]{"N", "E", "S", "W"};
this.socket = socket;
this.conCount = conCount;
System.out.println("New connection id: " + Players[conCount]);
}
public void run() {
try {
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
//here is info what player are you
out.println("You are player on position " + Players[conCount]);
while (true) {
synchronized (this) {
if (counter % 4 == conCount) {
while (true) {
out.println("Your turn " + Players[conCount] + ", please input the text: ");
String input = in.readLine();
System.out.println("\t" + Players[conCount] + " : " + input);
counter += 1;
//for now only the stringOnServer is simply echo
stringOnServer = input;
System.out.println("\tCurrent string on server = " + stringOnServer);
try {
this.wait();
} catch (InterruptedException ex) {
Logger.getLogger(Serwer.class.getName()).log(Level.SEVERE, null, ex);
}
break;
}
} else {
this.notify();
}
}
}
} catch (IOException e) {
System.out.println("error with player: " + Players[conCount] + ": " + e);
} finally {
try {
socket.close();
} catch (IOException e) {
System.out.println("can't closed");
}
System.out.println("connection with player" + Players[conCount] + " terminated");
}
}
}
}
Client's code is really simple, but if someone will have time and patience to test it I add it to:
package klient;
import java.net.*;
import java.io.*;
public class Klient {
public static void main(String[] args) throws IOException {
try {
Socket s = new Socket("127.0.0.1", 9898);
String answer;
System.out.println("Welcome on the server of auction.");
//Here is displayed info from server what player are you
BufferedReader fromServer = new BufferedReader(new InputStreamReader(s.getInputStream()));
System.out.println(fromServer.readLine());
while (true) {
System.out.println(fromServer.readLine());
PrintWriter out = new PrintWriter(s.getOutputStream(), true);
BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
answer = input.readLine();
out.println(answer);
}
} catch (ConnectException ex) {
System.out.println("There are 4 players on server or server is closed, try again later");
}
}
}
The problem is in this loop in connection class with counter.
Thanks in advance for your help :)

You have to call notify() from another thread. Your current thread is waiting and cannot notify itself.

java chat program via internet [closed]

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well, what i want to do is basically, to make a client server chat program that works over internet, ive done a basic one that works flawlessly over lan, but cant get it right over the internet..
Server :
public class Server extends javax.swing.JFrame {
HashMap<String,PrintWriter> map = new HashMap<String,PrintWriter>();
ArrayList clientOutputStreams = new ArrayList();
ArrayList<String> onlineUsers = new ArrayList();
int port = 5080;
Socket clientSock = null;
public class ClientHandler implements Runnable {
BufferedReader reader;
Socket sock;
PrintWriter client;
public ClientHandler(Socket clientSocket, PrintWriter user) {
// new inputStreamReader and then add it to a BufferedReader
client = user;
try {
sock = clientSocket;
InputStreamReader isReader = new InputStreamReader(sock.getInputStream());
reader = new BufferedReader(isReader);
System.out.println("first");
} // end try
catch (Exception ex) {
System.out.println("error beginning StreamReader");
} // end catch
} // end ClientHandler()
#Override
public void run() {
System.out.println("run method is running");
String message;
String[] data;
String connect = "Connect";
String disconnect = "Disconnect";
String chat = "Chat";
try {
while ((message = reader.readLine()) != null) {
ta1.append(message + "\n");
ta1.repaint();
System.out.println("Received: " + message);
data = message.split("#");
for (String token : data) {
System.out.println(token);
}
System.out.println(data[data.length - 1] + " datalast");
if (data[2].equals(connect)) {
tellEveryone((data[0] + "#" + data[1] + "#" + chat));
userAdd(data[0]);
map.put(data[0], client);
} else if (data[2].equals(disconnect)) {
System.out.println("barpppppppppp");
tellEveryone((data[0] + "#has disconnected." + "#" + chat));
userRemove(data[0]);
map.remove(data[0]);
} else if (data[2].equals(chat)) {
tellEveryone(message);
} else {
System.out.println("No Conditions were met.");
}
} // end while
} // end try
catch (Exception ex) {
System.out.println("lost a connection");
System.out.println(ex.getMessage());
clientOutputStreams.remove(client);
} // end catch
} // end run()
}
public void go() {
// clientOutputStreams = new ArrayList();
try {
ServerSocket serverSock = new ServerSocket(port);
System.out.println("ServerSocket Created !");
System.out.println("Started listening to port " + port);
while (true) {
// set up the server writer function and then begin at the same
// the listener using the Runnable and Thread
clientSock = serverSock.accept();
PrintWriter writer = new PrintWriter(clientSock.getOutputStream());
ta1.append(writer + " ");
ta1.repaint();
System.out.println(writer);
clientOutputStreams.add(writer);
//data_of_names_and_output_streams.add(writer.toString());
// use a Runnable to start a 'second main method that will run
// the listener
Thread listener = new Thread(new Server.ClientHandler(clientSock, writer));
listener.start();
System.out.println("Server Thread for 'new player' was started");
System.out.println("got a connection");
} // end while
} // end try
catch (Exception ex) {
System.out.println("error making a connection");
} // end catch
} // end go()
public void userAdd(String data) {
String message;
String add = "# #Connect", done = "Server# #Done";
onlineUsers.add(data);
String[] tempList = new String[(onlineUsers.size())];
onlineUsers.toArray(tempList);
for (String token : tempList) {
message = (token + add);
tellEveryone(message);
System.out.println(message);
}
tellEveryone(done);
}
public void userRemove(String data) {
System.out.println(onlineUsers.size() + " is size of online users");
System.out.println(clientOutputStreams.size() + " is size of ous");
String message;
String add = "# #Connect", done = "Server# #Done";
onlineUsers.remove(data);
String[] tempList = new String[(onlineUsers.size())];
onlineUsers.toArray(tempList);
for (String token : tempList) {
message = (token + add);
tellEveryone(message);
}
tellEveryone(done);
}
public void tellEveryone(String message) {
System.out.println(onlineUsers.size() + " is size of online users");
System.out.println(clientOutputStreams.size() + " is size of ous");
// jButton1.doClick();
// sends message to everyone connected to server
Iterator it = clientOutputStreams.iterator();
if (message.length() < 250) {
System.out.println("inside it");
while (it.hasNext()) {
try {
PrintWriter writer = (PrintWriter) it.next();
writer.println(message);
// l1.setText(message);
System.out.println("Sending " + message);
writer.flush();
} // end try
catch (Exception ex) {
System.out.println("error telling everyone");
} // end catch
}
} else {
try {
clientSock.close();
} catch (IOException ex) {
Logger.getLogger(Server.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
/**
* Creates new form Server
*/
public Server() {
initComponents();
ta1.repaint();
}
public static void main(String args[]) throws Exception {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Server().setVisible(true);
}
});
new Server().go();
}
} //end form
Client : jbutton1 is setting up connection,jbutton2 sends the message.
public class Client extends javax.swing.JFrame {
boolean sent, receive;
SimpleDateFormat sdf;
String ip;
String username;
Socket sock;
BufferedReader reader;
PrintWriter writer;
ArrayList<String> userList = new ArrayList();
Boolean isConnected = false;
DefaultListModel dlm;
public Client() {
initComponents();
dlm = (DefaultListModel) l1.getModel();
ip = JOptionPane.showInputDialog("Enter the IP of the server to connect");
}
public class IncomingReader implements Runnable {
public void run() {
String stream;
String[] data;
String done = "Done", connect = "Connect", disconnect = "Disconnect", chat = "Chat", battlerequest = "battlerequest";
try {
while ((stream = reader.readLine()) != null) {
data = stream.split("#");
System.out.println(stream + " ------------------------ data");
if (data[2].equals(chat)) {
sdf = new SimpleDateFormat("HH:mm:ss");
t.append("(" + sdf.format(new Date()) + ") " + data[0] + ": " + data[1] + "\n");
//t.setText("<html><b>hi" + 3 + 3 + "</b></html>");
} else if (data[2].equals(connect)) {
t.removeAll();
userAdd(data[0]);
} else if (data[2].equals(disconnect)) {
userRemove(data[0]);
} else if (data[2].equals(done)) {
dlm.removeAllElements();
writeUsers();
userList.clear();
} else {
System.out.println("no condition met - " + stream);
}
}
} catch (Exception ex) {
System.out.println(ex.getMessage() + " hi");
}
}
}
public void ListenThread() {
Thread IncomingReader = new Thread(new Client.IncomingReader());
IncomingReader.start();
}
public void userAdd(String data) {
userList.add(data);
}
public void userRemove(String data) {
t.setText(t1.getText() + data + " has disconnected.\n");
}
public void writeUsers() {
String[] tempList = new String[(userList.size())];
userList.toArray(tempList);
for (String token : tempList) {
//ul.append( token + "\n");
dlm.addElement(token);
// ul.setText(ul.getText() + token + '\n');
}
}
public void sendDisconnect() {
String bye = (username + "# #Disconnect");
try {
writer.println(bye); // Sends server the disconnect signal.
writer.flush(); // flushes the buffer
} catch (Exception e) {
t.append("Could not send Disconnect message.\n");
}
}
public void Disconnect() {
try {
t.append("Disconnected.\n");
sock.close();
} catch (Exception ex) {
t.append("Failed to disconnect. \n");
}
isConnected = false;
n.setEditable(true);
dlm.removeAllElements();
// ul.setText("");
}
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
if (isConnected == false && !n.getText().equals("")) {
username = n.getText();
n.setEditable(false);
try {
sock = new Socket(ip, 5080);
InputStreamReader streamreader = new InputStreamReader(sock.getInputStream());
reader = new BufferedReader(streamreader);
writer = new PrintWriter(sock.getOutputStream());
writer.println(username + "#has connected.#Connect"); // Displays to everyone that user connected.
writer.flush(); // flushes the buffer
isConnected = true;
jLabel4.setText(n.getText());
//t.append( "<html><font color = \"black\"><b>Server : Welcome,</b></font></html>"+username);
//t1.setText("<html><font color=\"red\">yo</font></html>");
// Used to see if the client is connected.
} catch (Exception ex) {
t.append("Cannot Connect! Try Again. \n");
n.setEditable(true);
}
ListenThread();
} else if (isConnected == true) {
t.append("You are already connected. \n");
} else if (n.getText().equals("")) {
t.append("Enter a valid name \n");
}
}
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
String nothing = "";
if ((t1.getText()).equals(nothing)) {
t1.setText("");
t1.requestFocus();
} else {
try {
writer.println(username + "#" + t1.getText() + "#" + "Chat");
writer.flush(); // flushes the buffer
} catch (Exception ex) {
t.append("Message was not sent. \n");
}
t1.setText("");
t1.requestFocus();
}
t1.setText("");
t1.requestFocus(); // TODO add your handling code here:
}
private void dicsActionPerformed(java.awt.event.ActionEvent evt) {
sendDisconnect();
Disconnect(); // TODO add your handling code here:
}
i have also port forwarded the ports i am going to use - ie. 5080
now when my friend opens the client program from his computer from his home, i tell him to enter the ip as 192.168.1.2 coz thats what is saved when i open cmd and type ipconfig....
sometimes i think that the ip address i gave him is wrong coz 192.168.1.2 is i guess lan or internal ip address, so then, so do i do ? where do i get the correct ip address ? or is something else wrong in my code ?

192.168.1.2 is a non-routable IP. Click here to get your current external IP (unless your IP address is static, it may change periodically).
If you were to sign up for a dynamic dns service (here for example), then you could give your friend a "domain name" (e.g. something.dnsdynamic.com) and the service would update when your IP address changes.