Develop Reference

Java socket Json

UPDATED
There is my updated code after the response,
I have one problem, now, i didn't receive anything :
Problem :
Connexion cliente reçue.
Lancement du traitement de la connexion cliente
Exception in thread "Thread-1" java.lang.NullPointerException
at cuisine.TimeServer.onResponseReceived(TimeServer.java:85)
at cuisine.ClientProcessor.run(ClientProcessor.java:43)
at java.base/java.lang.Thread.run(Thread.java:844)
TimeServer: 85 : Callback
#Override
public void onResponseReceived(String response) {
// When the response is received from ClientProcessor
// this method is called (by ClientProcessor).
// Your response is the parameter String response.
callback.onResponse(response);
}
Client processor: 43 :
server.onResponseReceived(response);
One client can connect but i can't receive anything : Json or text.
There is my new Java Code :
Main.java :
import cuisine.TimeServer.OnResponseReceivedListener;
public class main implements OnResponseReceivedListener {
public static void main(String[] args) throws IOException {
String host = "192.168.1.21";
int port = 8080;
TimeServer ts = new TimeServer(host, port);
ts.open();
System.out.println("------------Connected ! ------------");
}
#Override
public void onResponse(String response) {
doSomethingWith(response);
System.out.println("REPONSE : ");
System.out.println(response);
}
private void doSomethingWith(String response) {
System.out.println("REPONSE : ");
System.out.println(response);
}
}
I don't really know how to use the response now, because the sysout "RESPONSE" is not in my console
TimeServer.java :
...
import cuisine.ClientProcessor.Server;
public class TimeServer implements Server {
public interface OnResponseReceivedListener {
void onResponse(String response);
}
private int port = 2345;
private String host = "127.0.0.1";
private ServerSocket server = null;
private boolean isRunning = true;
private OnResponseReceivedListener callback;
public TimeServer() {
try {
server = new ServerSocket(port, 100, InetAddress.getByName(host));
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public TimeServer(String pHost, int pPort) {
host = pHost;
port = pPort;
try {
server = new ServerSocket(port, 100, InetAddress.getByName(host));
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public void open() {
Thread t =
new Thread(
new Runnable() {
public void run() {
while (isRunning == true) {
try {
Socket client = server.accept();
System.out.println("Connexion cliente reçue.");
ClientProcessor c = new ClientProcessor(client);
Thread t = new Thread(c);
// Don't forget to define the Server for ClientProcessor
c.addServer(TimeServer.this);
t.start();
} catch (IOException e) {
e.printStackTrace();
}
}
try {
server.close();
} catch (IOException e) {
e.printStackTrace();
server = null;
}
}
});
t.start();
}
#Override
public void onResponseReceived(String response) {
// When the response is received from ClientProcessor
// this method is called (by ClientProcessor).
// Your response is the parameter String response.
callback.onResponse(response);
}
public void addOnResponseReceivedListener(OnResponseReceivedListener listener) {
callback = listener;
}
public void removeOnResponseReceivedListener() {
callback = null;
}
public void close() {
isRunning = false;
}
}
ClientProcessor.java :
public class ClientProcessor implements Runnable {
public interface Server {
void onResponseReceived(String response);
}
private Socket sock;
private PrintWriter writer = null;
private BufferedInputStream reader = null;
public List<Dish> dish;
// Your server instance
private Server server;
public ClientProcessor(Socket pSock) {
this.sock = pSock;
}
public void run() {
System.err.println("Lancement du traitement de la connexion cliente");
boolean closeConnexion = false;
while (!sock.isClosed()) {
try {
writer = new PrintWriter(sock.getOutputStream());
reader = new BufferedInputStream(sock.getInputStream());
String response = read();
// report the response to TimeServer
server.onResponseReceived(response);
InetSocketAddress remote = (InetSocketAddress) sock.getRemoteSocketAddress();
String debug = "";
debug = "Thread : " + Thread.currentThread().getName() + ". ";
debug += "Demande de l'adresse : " + remote.getAddress().getHostAddress() + ".";
debug += " Sur le port : " + remote.getPort() + ".\n";
debug += "\t -> Commande reçue : " + response + "\n";
System.err.println("\n" + debug);
String toSend = "";
switch (response.toUpperCase()) {
case "ORDER":
toSend = "Dish";
break;
case "CLOSE":
toSend = "Communication terminée";
closeConnexion = true;
break;
default:
toSend = "Commande inconnu !";
break;
}
writer.write(toSend);
writer.flush();
if (closeConnexion) {
System.err.println("COMMANDE CLOSE DETECTEE ! ");
writer = null;
reader = null;
sock.close();
break;
}
} catch (SocketException e) {
System.err.println("LA CONNEXION A ETE INTERROMPUE ! ");
break;
} catch (IOException e) {
e.printStackTrace();
}
}
}
public void addServer(Server server) {
this.server = server;
}
private void removeServer() {
server = null;
}
// La méthode que nous utilisons pour lire les réponses
private String read() throws IOException {
String response = "";
int stream;
byte[] b = new byte[4096];
stream = reader.read(b);
response = new String(b, 0, stream);
return response;
}
}
Thanks,
Benjamin.

Update (updated Main.java)
Update No2 (Removed static methods from Main.java and use a Main object)
Edit: (removed previous answer about sockets)
This is the json response, now i want to use it in my main : on
another class in the same package.
Since you've stated that you are getting a response from client but you don't know how to manipulate it in your Main class then your issue is not about sockets.
A solution: Use callbacks:
ClientProcessor will report the response to TimeServer.
TimeServer will report that response to Main.
Make ClientProcessor aware of the server and report when the response is fetched.
public class ClientProcessor implements Runnable {
public interface Server {
void onResponseReceived(String response);
}
private Socket sock;
private PrintWriter writer = null;
private BufferedInputStream reader = null;
public List<Dish> dish;
// Your server instance
private Server server;
public ClientProcessor(Socket pSock) {
this.sock = pSock;
}
public void run() {
System.err.println("Lancement du traitement de la connexion cliente");
boolean closeConnexion = false;
while (!sock.isClosed()) {
try {
writer = new PrintWriter(sock.getOutputStream());
reader = new BufferedInputStream(sock.getInputStream());
String response = read();
// report the response to TimeServer
server.onResponseReceived(response);
InetSocketAddress remote = (InetSocketAddress) sock.getRemoteSocketAddress();
String debug = "";
debug = "Thread : " + Thread.currentThread().getName() + ". ";
debug += "Demande de l'adresse : " + remote.getAddress().getHostAddress() + ".";
debug += " Sur le port : " + remote.getPort() + ".\n";
debug += "\t -> Commande reçue : " + response + "\n";
System.err.println("\n" + debug);
String toSend = "";
switch (response.toUpperCase()) {
case "ORDER":
toSend = "Dish";
break;
case "CLOSE":
toSend = "Communication terminée";
closeConnexion = true;
break;
default:
toSend = "Commande inconnu !";
break;
}
writer.write(toSend);
writer.flush();
if (closeConnexion) {
System.err.println("COMMANDE CLOSE DETECTEE ! ");
writer = null;
reader = null;
sock.close();
break;
}
} catch (SocketException e) {
System.err.println("LA CONNEXION A ETE INTERROMPUE ! ");
break;
} catch (IOException e) {
e.printStackTrace();
}
}
}
private void addServer(Server server) {
this.server = server;
}
private void removeServer() {
server = null;
}
// La méthode que nous utilisons pour lire les réponses
private String read() throws IOException {
String response = "";
int stream;
byte[] b = new byte[4096];
stream = reader.read(b);
response = new String(b, 0, stream);
return response;
}
}
Now go to TimeServer and make it aware of Main (same procedure as before). You must also need to report the response to Main when its being received from ClientProcessor.
public class TimeServer implements Server {
public interface OnResponseReceivedListener {
void onResponse(String response);
}
private int port = 2345;
private String host = "127.0.0.1";
private ServerSocket server = null;
private boolean isRunning = true;
private OnResponseReceivedListener callback;
public TimeServer() {
try {
server = new ServerSocket(port, 100, InetAddress.getByName(host));
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public TimeServer(String pHost, int pPort) {
host = pHost;
port = pPort;
try {
server = new ServerSocket(port, 100, InetAddress.getByName(host));
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public void open() {
Thread t =
new Thread(
new Runnable() {
public void run() {
while (isRunning == true) {
try {
Socket client = server.accept();
System.out.println("Connexion cliente reçue.");
Thread t = new Thread(new ClientProcessor(client));
// Don't forget to define the Server for ClientProcessor
t.addServer(TimeServer.this);
t.start();
} catch (IOException e) {
e.printStackTrace();
}
}
try {
server.close();
} catch (IOException e) {
e.printStackTrace();
server = null;
}
}
});
t.start();
}
#Override
public void onResponseReceived(String response) {
// When the response is received from ClientProcessor
// this method is called (by ClientProcessor).
// Your response is the parameter String response.
callback.onResponse(response);
}
public void addOnResponseReceivedListener(OnResponseReceivedListener listener) {
callback = listener;
}
public void removeOnResponseReceivedListener() {
callback = null;
}
public void close() {
isRunning = false;
}
}
Finaly, make your Main to listen to TimeServer and do something when it receives the response.
public class Main implements OnResponseReceivedListener {
public static void main(String[] args) {
Main application = new Main();
TimeServer ts = application.createTimeServer();
ts.addOnResponseReceivedListener(application);
ts.open();
System.out.println("------------Connected ! ------------");
}
#Override
public void onResponse(String response) {
doSomethingWith(response);
}
private void doSomethingWith(String response) {
// Your logic for the response here...
}
private TimeServer createTimeServer() {
String host = "192.168.43.178";
int port = 8080;
return new TimeServer(host, port);
}
}

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
}

Java Server-Client with Multiple Client

I have been trying to make a multiple client chatting apps for a few days, and I have read the document below, and find some suggestions online, and I come up with the below code.
https://docs.oracle.com/javase/tutorial/networking/sockets/clientServer.html#later
What I am thinking is to make an app and start the Server, and Send the Message by the methods
"startServer();" and
"sendFromServer(Serializable data)";
~~~~~The Problem is I start startServer() method the app turn frozen, so I know I am doing it the wrong way.~~~~~~~~
Can anyone please give me some hint on how to correctly create a multiple client-server app?
public class Server {
private ServerSocket server;
private Socket socket;
private int port;
private Consumer<Serializable> consume;
private ConnectionThread thread;
private List<ConnectionThread> threads =
new ArrayList<ConnectionThread>();
public Server(int port, Consumer<Serializable> consume){
this.port= port;
this.consume = consume;
try {
server = new ServerSocket(port);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void startServer() {
if(server == null) {
System.out.println("no server");
}
while(true) {
try {
socket = server.accept();
} catch (IOException e) {
e.printStackTrace();
}
ConnectionThread thread =new ConnectionThread(socket);
threads.add(thread);
thread.start();
}
}
public void sendFromServer(Serializable data) throws IOException {
thread.out.writeObject(data);
}
private class ConnectionThread extends Thread {
private Socket socket;
private ObjectOutputStream out;
private ConnectionThread(Socket socket){
this.socket = socket;
}
#Override
public void run(){
try {
ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
ObjectInputStream in = new ObjectInputStream(socket.getInputStream());
this.out = out;
while(true){
Serializable data = (Serializable)in.readObject();
consume.accept(data);
}
}catch (IOException e){
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
}
Client Side: (I am trying to make one Pane holding the two chats at the moment, using two buttons to call the"startServer();" and "startClient();" respectively)
public class Client {
private int port;
private String ip;
private Consumer<Serializable> consume;
private ConnectionThread thread = new ConnectionThread();
public Client(int port, String ip, Consumer<Serializable> consume){
this.port = port;
this.ip = ip;
this.consume = consume;
}
public void startClient(){
thread.start();
}
public void sendFromClient(Serializable data) throws IOException{
thread.out.writeObject(data);
}
private class ConnectionThread extends Thread{
private Socket socket;
private ObjectOutputStream out;
#Override
public void run(){
try(
Socket socket = new Socket(ip, port);
ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
ObjectInputStream in = new ObjectInputStream(socket.getInputStream());
) {
this.out = out;
while(true){
Serializable data = (Serializable)in.readObject();
consume.accept(data);
}
} catch (Exception e) {
e.printStackTrace();;
}
}
}
}
the FXML controller class
public class chatController{
#FXML private TextArea SerBoard, CliBoard;
#FXML private TextField SerTxt,CliTxt;
#FXML private Button SerConnect, CliConnect;
private Server server = createSer();
private Client client = createCli();
private int port= 5555;
private String ip = "localhost";
private boolean connected =
(server==null && client==null)? false: true;
#FXML
public void setOnSerConnect(ActionEvent event) {
server.startServer();
}
#FXML
public void setOnCliConnect(ActionEvent event) {
client.startClient();
}
private Client createCli() {
Client client = new Client(port, ip, data->{
Platform.runLater(() -> {
CliBoard.appendText(data.toString());
});
});
System.out.println("Client connect");
return client;
}
private Server createSer() {
Server server = new Server(port, data->{
Platform.runLater(()->{
SerBoard.appendText(data.toString());
});
});
System.out.println("Server connect");
return server;
}
#FXML
public void setOnSerText(ActionEvent event) {
if(connected) {
String input = SerTxt.getText();
String mes = "Server: "+ input + "\n";
SerTxt.clear();
SerBoard.appendText(mes);
try {
server.sendFromServer(mes);
} catch (IOException e) {
e.printStackTrace();
}
}
}
#FXML
public void setOnCliText(ActionEvent event) {
if(connected) {
String input = SerTxt.getText();
String mes = "Client: "+ input + "\n";
SerTxt.clear();
SerBoard.appendText(mes);
try {
client.sendFromClient(mes);
} catch (IOException e) {
e.printStackTrace();
}
}
}
}

Should be rather
public void startServer() {
if(server == null) {
System.out.println("no server");
}
while(true) {
try {
socket = server.accept();
ConnectionThread thread =new ConnectionThread(socket);
threads.add(thread);
thread.start();
} catch (IOException e) {
e.printStackTrace();
}
}
This way u will acceppt all client connections.
Also startServer must be invoked using Platform.runLater as well.

Client - Server - Client exception with streams in Java

I'm new to socket programming in Java and I'm trying to create a simple chat between 2 clients through a server. The server will receive message from this client and send to the other.
Server
public class ServerV2 extends JFrame {
/**
*
*/
private static final long serialVersionUID = -1958631621285336523L;
private ServerSocket serverSocket;
private ObjectOutputStream outputStream;
private int port;
private ArrayList<ClientHandler> clients = new ArrayList<ClientHandler>();
private JTextArea messageBox;
private void initializeUI() {
messageBox = new JTextArea();
add(new JScrollPane(messageBox), BorderLayout.CENTER);
setTitle("Server");
setSize(256, 256);
setVisible(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
public ServerV2(int port) {
this.port = port;
initializeUI();
}
public void startServer() {
try {
serverSocket = new ServerSocket(port, 100);
while (true) {
try {
Socket clientSocket = serverSocket.accept();
ClientHandler client = new ClientHandler(this, clientSocket);
clients.add(client);
client.start();
} catch (Exception e) {
e.printStackTrace();
} finally {
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
void sendMessage(String message, ClientHandler fromClient) {
try {
for (ClientHandler clientHandler : clients) {
if (!clientHandler.equals(fromClient)) {
outputStream = new ObjectOutputStream(
clientHandler.getClient().getOutputStream());
outputStream.writeObject(message);
outputStream.flush();
}
}
showMessage(message, fromClient);
} catch (IOException e) {
System.out.println("What the heck are you trying to send?");
}
}
void showMessage(String message, ClientHandler fromClient) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
messageBox.append("\n" + fromClient.getUserName() + " said "
+ message);
}
});
}}
ClientHandler
public class ClientHandler extends Thread {
private ServerV2 server;
private Socket clientSocket;
private String userName;
private ObjectInputStream inputStream;
private String message;
public String getUserName() {
return userName;
}
public Socket getClient() {
return clientSocket;
}
public ClientHandler(ServerV2 server, Socket client) {
this.server = server;
try {
inputStream = new ObjectInputStream(client.getInputStream());
} catch (IOException e) {
e.printStackTrace();
}
this.clientSocket = client;
}
#Override
public void run() {
try {
userName = (String)inputStream.readObject();
readMessage();
} catch (Exception e) {
e.printStackTrace();
}
}
private void readMessage() throws IOException {
do {
try {
message = (String)inputStream.readObject();
server.sendMessage(message, this);
} catch (ClassNotFoundException e) {
}
} while (!message.equals("EXIT"));
}
#Override
public boolean equals(Object obj) {
if (obj == null) return false;
ClientHandler client = (ClientHandler)obj;
if (this.userName.equals(client.getUserName())) return true;
return false;
}}
Client
public class Client extends JFrame {
/**
*
*/
private static final long serialVersionUID = -3219203310153720970L;
private JTextField txtMessageInput;
private JTextArea messageBox;
private Socket clientSocket;
private String message;
private ObjectOutputStream outputStream;
private ObjectInputStream inputStream;
private String host;
private int port;
private String userName;
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public Client(String host, int port, String userName) {
this.host = host;
this.port = port;
this.userName = userName;
initializeUI();
}
private void initializeUI() {
txtMessageInput = new JTextField();
txtMessageInput.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
sendMessage(e.getActionCommand());
txtMessageInput.setText("");
}
});
messageBox = new JTextArea();
add(txtMessageInput, BorderLayout.NORTH);
add(new JScrollPane(messageBox), BorderLayout.CENTER);
setTitle("Client");
setSize(256, 256);
setVisible(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
public void startClient() {
try {
System.out.println("Starting client with username " + userName);
// Connect to server
connectToServer();
// Setup streams to send and receive data from server
setupStreams();
// send username to server
outputStream.writeObject(userName);
// read messages from server
readMessage();
} catch (EOFException e) {
System.out.println("You closed the connection.");
} catch (IOException e) {
e.printStackTrace();
} finally {
closeConnection();
}
}
private void connectToServer() {
System.out.println("Searching for server ...");
try {
clientSocket = new Socket(InetAddress.getByName(host), port);
} catch (Exception e) {
e.printStackTrace();
}
System.out.println("Connected to server.");
}
private void setupStreams() throws IOException {
System.out.println("Setup streams ...");
outputStream = new ObjectOutputStream(clientSocket.getOutputStream());
inputStream = new ObjectInputStream(clientSocket.getInputStream());
System.out.println("Streams are setup ...");
}
private void readMessage() throws IOException {
do {
try {
message = (String) inputStream.readObject();
showMessages(message);
} catch (ClassNotFoundException e) {
System.out.println("Blah blah blah, I don't know this language ...");
}
} while (!message.equals("EXIT"));
}
public void sendMessage(String message) {
try {
outputStream.writeObject(message);
outputStream.flush();
showMessages(message);
} catch (IOException e) {
System.out.println("What the heck are you trying to send?");
}
}
private void closeConnection() {
System.out.println("Close connections ...");
try {
inputStream.close();
outputStream.close();
clientSocket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
private void showMessages(String message) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
messageBox.append(message + "\n");
}
});
}}
The problem is when I start 2 clients and a server and send message, the server throws exception
java.io.EOFException
at java.io.ObjectInputStream$BlockDataInputStream.peekByte(Unknown Source)
at java.io.ObjectInputStream.readObject0(Unknown Source)
at java.io.ObjectInputStream.readObject(Unknown Source)
at awesomechat.server.ClientHandler.readMessage(ClientHandler.java:54)
at awesomechat.server.ClientHandler.run(ClientHandler.java:45)
and one client throws
java.io.StreamCorruptedException: invalid type code: AC
at java.io.ObjectInputStream.readObject0(Unknown Source)
at java.io.ObjectInputStream.readObject(Unknown Source)
at awesomechat.client.Client.readMessage(Client.java:106)
at awesomechat.client.Client.startClient(Client.java:76)
at awesomechat.client.StartClient.main(StartClient.java:6)
So anyone please show me the point why I get these two exceptions and how to solve it.

Chat Application using socket not working over Internet in Java

I am currently developing chat application working over Internet.currently my application working fine over LAN but not working over Internet.I have also used port forwarding.I have done setting in modem and forward the port to private IP address but still it's not working.I got the error that "server isn't found".Please suggest me what I have to do and tell,Am I done the correct setting in modem or not??
Below is my server code...
Server.java
import java.util.*;
import java.net.*;
import java.io.*;
class Server implements ChatConstants
{
private static Vector list;
private ServerSocket ssocket ;
private Service service;
private static Socket socket;
private boolean done=false;
private static Hashtable userTable = new Hashtable();
private static Hashtable _userList = new Hashtable();
private static Hashtable _conflist = new Hashtable();
public Server() throws UnknownHostException
{
System.out.println("Initializing...");
list=new Vector(BACKLOG);
try {
ssocket= new ServerSocket(SERVER_PORT,BACKLOG);
}
catch(Exception e) {
e.printStackTrace();
System.out.println("Inside constructor"+e);
}
start();
}
public void start() throws UnknownHostException
{
byte[] data;
int header;
Socket _socket = null;
String hostname = null;
System.out.println("Server successfully started at "
+InetAddress.getLocalHost().toString()
+" port "+SERVER_PORT);
while(!done) {
try
{
_socket=ssocket.accept();
if(_socket != null) {
synchronized(list) {
list.addElement(_socket);
}
DataInputStream dis=new DataInputStream(_socket.getInputStream());
data = new byte[MAX_MESSAGE_SIZE];
dis.read(data);
Message message = ((Message)ChatUtils.bytesToObject(data));
System.out.println("Joined client "
+message._username+" at "+message._host+"...");
synchronized(userTable) {
userTable.put(message._username,_socket);
}
addUser(message);
sendUserList(message);
writeToClients(message);
service = new Service(_socket,hostname,message._user);
}
}
catch(Exception e) {
e.printStackTrace();
System.out.println("Thread exception"+e);
try {
_socket.close();
}
catch(Exception ex) {
ex.printStackTrace();
System.out.println("ERROR CLOSING SOCKET");
}
}
}//END WHILE
}
private void addUser(Message message)
{
synchronized(_userList) {
_userList.put(message._user.toString(),message._user);
}
}
public static void updateUser(User user)
{
User myuser;
synchronized(_userList) {
_userList.put(user.toString(),user);
}
}
public static synchronized void writeToClients(Message message)
{
byte[] data;
DataOutputStream dos;
for(int count=0;count<list.size();count++) {
try {
dos=new
DataOutputStream(((Socket)list.elementAt(count)).getOutputStream());
data=ChatUtils.objectToBytes(message);
dos.write(data,0,data.length);
}
catch(Exception e) {
e.printStackTrace();
System.out.println("Output exception");
}
}//END FOR
}
public static void writeToClient(Message message)
{
Socket socket;
byte[] data;
DataOutputStream dos;
synchronized(userTable) {
try {
socket = (Socket)userTable.get(message._destination);
dos=new DataOutputStream(socket.getOutputStream());
data=ChatUtils.objectToBytes(message);
dos.write(data,0,data.length);
}
catch(Exception e) {
e.printStackTrace();
System.out.println("SEND EXCEPTION"+e);
}
}
}
public static void sendConferenceListToClient(Message message)
{
Socket socket;
byte[] data;
DataOutputStream dos;
synchronized(userTable) {
try {
Message mymessage= new Message(CONFERENCE_LIST);
Vector vector = (Vector)
_conflist.get(message._destination);
mymessage._username = message._username;
mymessage._destination = message._destination;
mymessage.userlist = vector;
socket = (Socket)userTable.get(message._username);
if(socket!=null) {
dos=new DataOutputStream(socket.getOutputStream());
data=ChatUtils.objectToBytes(mymessage);
dos.write(data,0,data.length);
}
}
catch(Exception e) {
e.printStackTrace();
System.out.println("CONFERENCE LIST EXCEPTION"+e);
}
}
}
public static void writeToPublicChat(Message message)
{
Socket socket;
byte[] data;
DataOutputStream dos;
synchronized(_conflist) {
try {
Vector svector = (Vector)_conflist.get(message._destination);
for(int cnt=0;cnt<svector.size();cnt++) {
synchronized(userTable) {
try {
socket = (Socket)userTable.get((svector.get(cnt).toString()));
if(socket!=null) {
dos=new DataOutputStream(socket.getOutputStream());
data=ChatUtils.objectToBytes(message);
dos.write(data,0,data.length);
}
}
catch(Exception e) {
e.printStackTrace();
System.out.println("PUBLIC CHAT EXCEPTION"+e);
}
}
}
} catch(Exception e){
e.printStackTrace();
System.out.println("PUBLIC EXCEPTION"+e);
}
}
}
public static void inviteToPublicChat(Vector svector,Message message)
{
Socket socket;
byte[] data;
DataOutputStream dos;
synchronized(_conflist) {
for(int cnt=0;cnt<svector.size();cnt++) {
synchronized(userTable) {
try {
socket = (Socket)userTable.get((svector.get(cnt).toString()));
if(socket != null) {
dos=new DataOutputStream(socket.getOutputStream());
data=ChatUtils.objectToBytes(message);
dos.write(data,0,data.length);
}
}
catch(Exception e) {
e.printStackTrace();
System.out.println("PUBLIC INVITE EXCEPTION"+e);
}
}
}
}
}
private void sendUserList(Message message)
{
int header=0;
String destination;
header=message._header;
destination = message._destination;
message._header = USERS_LIST;
message._destination = message._username;
message.userlist = new Vector(_userList.values());
writeToClient(message);
//Restore the headers
message._destination = destination;
message._header = header;
}
public static synchronized void removeUser(User user)
{
try {
Socket socket = (Socket)userTable.get(user.toString());
list.removeElement(socket);
_userList.remove(user.toString());
userTable.remove(user.toString());
}
catch(Exception e) {
e.printStackTrace();
System.out.println("ERROR REMOVING SOCKET "+e);
}
}
public static synchronized void processClientMessage(Message message)
{
switch(message._header) {
case CHANGE_STATUS:
updateUser(message._user);
writeToClients(message);
break;
case CLIENT_LOGOUT:
removeUser(message._user);
writeToClients(message);
break;
case CONFERENCE_CREATE:
Vector myvector = new Vector();
myvector.add(message._username);
_conflist.put(message._user.toString(),myvector);
case CONFERENCE_INVITE:
inviteToPublicChat(message.userlist,message);
break;
case CONFERENCE_JOIN:
Vector vector=null;
vector = (Vector)
_conflist.get(message._destination.toString());
vector.add(message._username);
_conflist.put(message._destination.toString(),vector);
writeToPublicChat(message);
break;
case CONFERENCE_DENY:
//_conflist.remove(message._user.toString(),message.userlist);
writeToPublicChat(message);
break;
case CONFERENCE_LEAVE:
Vector vectors =(Vector)
_conflist.get(message._destination.toString());
for(int count=0;count<vectors.size();count++) {
if(message._username.equals((vectors.elementAt(count).toString())))
vectors.remove(count);
}
if(vectors.size() != 0)
_conflist.put(message._user.toString(),vectors);
else//IF THERE ARE NO MORE USERS
_conflist.remove(message._user.toString());//DONE CONFERENCE
writeToPublicChat(message);
break;
case PUBLIC_CHAT:
writeToPublicChat(message);
break;
case CONFERENCE_LIST:
sendConferenceListToClient(message);
break;
default:
writeToClient(message);
}
}
public static void main(String args[]) throws Exception
{
Server chatserver=new Server();
}
}
//
// Service: Service class for each clients connected to server.
//
class Service implements Runnable, ChatConstants
{
private DataInputStream dis;
private Socket socket;
private boolean done=false;
private Thread thread;
private String hostname;
private User user;
public Service(Socket _socket,String _hostname,User user)
{
try {
this.socket = _socket;
this.hostname=_hostname;
this.user = user;
dis=new DataInputStream(socket.getInputStream());
thread=new Thread(this,"SERVICE");
thread.start();
}
catch(Exception e){
e.printStackTrace();
System.out.println("service constructor"+e);
}
}
public void run()
{
byte[] data;
while(!done)
{
try {
data = new byte[MAX_MESSAGE_SIZE];
dis.read(data);
Message message = ((Message)ChatUtils.bytesToObject(data));
Server.processClientMessage(message);
}
catch(Exception e) {
e.printStackTrace();
done = true;
Server.removeUser(user);
Message message = new Message(CLIENT_LOGOUT);
user.isOnline = OFFLINE;
message._user = user;
Server.writeToClients(message);
try {
socket.close();
} catch(Exception se) {
se.printStackTrace();
System.out.println("ERROR CLOSING SOCKET "+se);
}
//System.out.println("SERVICE THREAD EXCEPTION"+e);
}
}//END WHILE
}
}
Thanks in advance.

I think the
ssocket= new ServerSocket(SERVER_PORT,BACKLOG);
is making the issue. Use the version
ssocket= new ServerSocket(SERVER_PORT,BACKLOG,LOCAL_INET_ADDRESS);
and bind server to some constant local IP. Now use the port forwarding in the modem, to forward all requests to that local ip. Make sure that the firewall is not preventing you to use the port. Since firewall may allow a local networking but not to web.