Thank you for taking time to explain each step in simple terms. I tried this on my own and was hung up on how each CH object could share 1 updated array list, but then you pointed out the beauty of static variables!
Remember to use 'Thread-Safe" collections or manage synchronization in this example.Our static arraylist is a shared resource, and can be accessed by multiple threads simultaneously, where each one can add, remove or read.
In the broadcastMessage method, why compare usernames when you can just do: if (clientHandler != this) since clientHandlers is just an array of the clientHandler instances. Also doing it this way allows there to be multiple users with the same username since it does not rely on unique usernames to broadcast correctly, but instead on the instances. (I have not tested it yet, but it should work, if it doesn't then I will update this comment) Edit: I said I would only update if it didn't work, but it worked and I thought I would update it anyways. TL;DR it works, and its probably the better way to do it.
Perfeito bom demais essa aula, ficou muito bom mesmo . Sem enrolação e sem complicação foi ótimo esse tutorial, valeu deixo o meu like e minha inscrição, obrigado
Nice video it was a really nice watch and i learned a bunch of new things from it! Can anyone please explain how to run it in CMD tho? (it looked cool)
Great cover of sockets in general. Just wanted to mention that I got an error in the ClientHandler whenever the Client exited. For some reason, the exception was not thrown and the bufferedReader read a "null" value from the input. I added this line and it worked: if(messageFromClient == null) throw new IOException(); By the way, if we wanted to create a network without the use of an intermediary server, so basically client-to-client direct communication. Any tips on how you could go about doing that? Thank you sir!
I met that problem, too. The things that if I applied your code, the server won't notify that the client who exited is leaving the chat. Is there another way to do that
@@ngocminhpham1358 You should add the code that you want to execute in the catch: try { messageFromClient = bufferedReader.readLine(); if(messageFromClient == null) throw new IOException(); broadcastMessage(messageFromClient); } catch(IOException e) { closeEverything(socket, bufferedReader, bufferedWriter); break; } Inside closeEverything, there should be a method called "removeClientHandler();" (this is in the video). If this method is executed then the server should be notifying everyone that the client has left the chat. Double check that you added this catch cluase as well as your "closeEverything" method.
This is very impressive and it works. I like your approach with clientHandlers. Im a little confused about how multiple clients can connect using the same port. When I did a similar project in C# i got an error saying something like "this port is already in use". Can anyone explain that to me?
Isn't it safer to convert public classes to private classes if they are not used in another class? or there is a reason for it? Thank you for this incredible work, your explanations are amazing !😍
I just wanted to say I love your content and how you interact with your fan base but I was also wondering how to run this program from command prompt and how to configure this for use over WAN networks. PS: this tutorial inspired me to make my own chat room project which has been my first real (successful) program.
Hey John thanks so much for the feedback! To run it over the command prompt you just have to go to where you made the java files and compile it like javac .java and then run it like java . And I have gotten a few questions about making these Java networking programs accessible over the internet and to be honest I am not entirely sure how to do it besides port forwarding or giving your server a public address. Im probably gonna take some time to look into this and make a video on it! 😀
Hey good to hear from you again! That is correct! And actually probably a better idea as I did not check for duplicate usernames provided by clients! 😄
Runnable passed to Thread in listenForMessage() could be implemented by lambda new Thread( () -> {/*code*/}); because Runnable interface has only 1 abstract method, thus making it functional interface.
Great video, loved it. Thank you for explaining the details. Is it possible to implement this structure of group chat with graphical user interface? Actually I tried but I couldn't figure it out. It simply didn't work
hello i have a question, what should i do to make them connect from different pcs and not on localhost. i tried some solutions but it always give me an error
Hey wittcode, I hope you see this, I loved the tutorial, and you explained everything very well with a hands on approach, but is it possible to run the clients on different computers? If so, how?
i gotchu just run a client-like file on a different computer and use the ip address of your server computer instead of "localhost", also make sure they're on the same network
At 23:40 shouldn't you be doing closeEverything(clientHandler.socket, clientHandler.bufferedReader, clientHandler.bufferedWriter) ? You are iterating through each of clientHandlers, and for each clientHandler, you push the message. Hence if u encounter an exception, you should be closing THAT particular clientHandler's connections. Same logic applies when we are removing the clientHandler from the array. Instead of passing 'this', shouldn't we pass clientHandler?
Heyo, thank you so much for the tutorial! I have a little problem though. If I close one of the client windows and start a new one. The chat is filled with the word "null" and I don't know what would cause it. Any idea how to fix it? 😅
Ran into the same issue. The fix is to do a null check for what bufferedReader.readLine() returns in run() method in ClientHandler.java, cuz readLine() will immediately return null if the the corresponding Client program gets terminated.
Extremely thankful for helping us in the easiest ways but, if i want to store every one of the texts sent in a file that stays in the "Server" and whenever a new client joins he/she gets all of the messages printed from the file in the console .. to do that what are the changes i should do?
I think this is the best video on RUclips about I/O streams and sockets.
Is there any way I can see your code
This dude literally explained my entire 5 months course in a 40 minute video
Thank you for taking time to explain each step in simple terms. I tried this on my own and was hung up on how each CH object could share 1 updated array list, but then you pointed out the beauty of static variables!
Thanks so much man! Also love your taste in music haha 🎸
@@WittCode hell ya Java and Punk Rock are a 90s dynamic duo🤘
@@WittCode can i make those names of clients in diferent color ?
@@og_yamiatan3957 I mean it's in the cmd prompt so prob not, but if you make a GUI for it you could find a way
This truly explains everything so clear, thanks man
Remember to use 'Thread-Safe" collections or manage synchronization in this example.Our static arraylist is a shared resource, and can be accessed by multiple threads simultaneously, where each one can add, remove or read.
This is so exciting!!! I had been trying other tutorials, even paid ones and had problems with all the others. On this one everything went perfect.
Haven't even finished the video yet but I'm happy I found this channel!
IT WORKED, THANKS I'VE BEEN LOOKING FOR THIS FOREVER, BUT NO TUTORIAL COULD EXPLAIN IT AS YOU DID
Let me just tell you one thing. Thanks for Being in RUclips to share content most are not capable of doing.
Thanks so much!
this video is a real gem for us cs students. thank you so much!
Great to hear! Yeah back when I was in school I had to code this for a class 😀
Wow man, you really clearly showed how to make such chat in Java, thanks a lot! :)
Thank you so much for this video! Very well explained, it helped me a lot for my university project.
THIS IS SO COOL! And I managed to reinforce sockets, IO, AND threads ALL AT ONCE
I understand all men you're a great teacher!!
Thx for your tutorial, I finally understand how socket work
Best video out here, thank you kind dude
So underrated!!! I wish you'll gain more subscribers and viewers. Amazing video
You explain everything so well and simple ♡
Great work! I love the thumbnail! So many WittCodes!
Thanks for the support Freddie! 😎
Thank you so much dude! Consider becoming a teacher in the future 🙏 You have that pedagogical talent :)
This is what, I looked for in Java. Thank you so.
Thank you, I had trubles with sending message to multiple clients, because of reading system input, thanks again!
Hey there thanks so much! Yeah the reading input part tripped me up for a while too! 😃
Lowkey saved my uni lab work xd , keep up the good work !!
You are a lifesaver man, thank you a lot you are saving me a ton of hours and nerves :)
Wow you are suck a great teacher. You explain every step. Thank you so much!
great video thanks for making it i was stuck on this for so long
I took a server side approach instead of a client side approach, love the video tho, thank you
thank you so much, this content deserves much more credit
Thanks so much! That means a lot! 😃
Thank you for this excellent content.
Thank you for the clear and concise explanation. I just subscribed you. I wish to watch your more videos.
😀
great video, wonderful explanations throughout too.
😀
Nice one man. Keep it up!
I'm so grateful to you, this really so helpful man thank you so much
In the broadcastMessage method, why compare usernames when you can just do: if (clientHandler != this)
since clientHandlers is just an array of the clientHandler instances. Also doing it this way allows there to be multiple users with the same username since it does not rely on unique usernames to broadcast correctly, but instead on the instances. (I have not tested it yet, but it should work, if it doesn't then I will update this comment)
Edit: I said I would only update if it didn't work, but it worked and I thought I would update it anyways. TL;DR it works, and its probably the better way to do it.
yah it sounds correct
Thank you! Learned a lot from this
Your content is amazing brother, keep it up! I would love to see this video with a GUI integration as you said in the end of the video.
Thanks so much Kevin! And I will certainly be making a GUI version of this! Probably using JavaFX 😀
@@WittCode , hey witt please do that asap
Very helpful! Thank you so much!
thank you! I liked this video.
Thank you so much!!! This is what I was finding!
your video is awesome and helped me a lot. thank you.
This is simply awesome man 👍❤️
You are lifesaver man, thank you a lot :)
Perfeito bom demais essa aula, ficou muito bom mesmo . Sem enrolação e sem complicação foi ótimo esse tutorial, valeu deixo o meu like e minha inscrição, obrigado
this is briliant my friends thank you so much
Great video all the best
Great to hear! Thanks for watching
thanks a lot bro, keep the good job.✌
Thank you very much for this!
thank you so much, saved my homework truly!
bro can you send code please
video is very helpful. Thank you.
Great content, learned a lot!
Is there anyway I can see your code by chance, that is if it's working
Thanks bro it has been very usefull for me
Which design patterns are we using in this program and which pattern I can implement into the code in addition to develop the code?
Love the thumbnail hahah
Sahil! Good to hear from you man! And yeah I thought it was the coolest one Ive made so far lol
Hello sir. Is the code still on your website? i can only seem to see some Javascript. Is it on a github page?
This helped me a lot, thanks!
Great video! Really helped!
Great tutorial!
Greetings from Ukraine! You are awesome! Thank you so much for this great tutorial. It helped me a lot.
Nice tutorial man, rly need something like tihs :D
Thanks so much! Also, love your username lol
this was perfect for me thank you
Thank you man, is that possible to chat only with one person from the group please share if you have such kind of code
Nice video it was a really nice watch and i learned a bunch of new things from it! Can anyone please explain how to run it in CMD tho? (it looked cool)
Great cover of sockets in general. Just wanted to mention that I got an error in the ClientHandler whenever the Client exited. For some reason, the exception was not thrown and the bufferedReader read a "null" value from the input. I added this line and it worked:
if(messageFromClient == null) throw new IOException();
By the way, if we wanted to create a network without the use of an intermediary server, so basically client-to-client direct communication. Any tips on how you could go about doing that?
Thank you sir!
I met that problem, too. The things that if I applied your code, the server won't notify that the client who exited is leaving the chat. Is there another way to do that
@@ngocminhpham1358 You should add the code that you want to execute in the catch:
try {
messageFromClient = bufferedReader.readLine();
if(messageFromClient == null) throw new IOException();
broadcastMessage(messageFromClient);
} catch(IOException e) {
closeEverything(socket, bufferedReader, bufferedWriter);
break;
}
Inside closeEverything, there should be a method called "removeClientHandler();" (this is in the video). If this method is executed then the server should be notifying everyone that the client has left the chat. Double check that you added this catch cluase as well as your "closeEverything" method.
@@fabiansvensson9588 thanks a lot!
@@fabiansvensson9588 Oh my god i was desperate while seaching the solution and boom i found your comment. You're a god.
at which line do you add this "if(messageFromClient == null) throw new IOException();" ?
thank you! Subscribed!
Real gem!!
Great video!
Why we can't run the server again? After it being in use? Like turn off the server and Re-open it.
beautiful! thanks! (do more java tutorials pls
i tried it it works but my message dont appear to other clients it only appears in my chat only not other chats'
Great tutorial, thanks
Thank you very much, man
Thank you very much!
This is very impressive and it works. I like your approach with clientHandlers. Im a little confused about how multiple clients can connect using the same port.
When I did a similar project in C# i got an error saying something like "this port is already in use". Can anyone explain that to me?
Many thanks Sir 😘
Isn't it safer to convert public classes to private classes if they are not used in another class? or there is a reason for it?
Thank you for this incredible work, your explanations are amazing !😍
thank uuuuu so much, this is so helpful
very helpful video !
Can you share the code, not able to find in the link you kept in description
I just wanted to say I love your content and how you interact with your fan base but I was also wondering how to run this program from command prompt and how to configure this for use over WAN networks.
PS: this tutorial inspired me to make my own chat room project which has been my first real (successful) program.
Hey John thanks so much for the feedback! To run it over the command prompt you just have to go to where you made the java files and compile it like javac .java and then run it like java . And I have gotten a few questions about making these Java networking programs accessible over the internet and to be honest I am not entirely sure how to do it besides port forwarding or giving your server a public address. Im probably gonna take some time to look into this and make a video on it! 😀
@@WittCode Thank you so much, I really appreciate you taking the time out of your day to respond to my request!
great channel
Shouldn't we rather use AtomicReferenceArray for the clientHandlers to avoid race conditions since more thread access it?
You are correct, use thread-safe collections or manage synchronization
awesome video i love it thankyouu
Helpful video thanks for making this. Can you do a server PC and a client mobile phone.
Very good!
tysm for this video! its great! one question tho.. at 21:14
couldn't you check if this!=clientHandler?
Hey good to hear from you again! That is correct! And actually probably a better idea as I did not check for duplicate usernames provided by clients! 😄
@@WittCode yeah i was wondering abt duplicate usernames lol
Runnable passed to Thread in listenForMessage() could be implemented by lambda
new Thread( () -> {/*code*/});
because Runnable interface has only 1 abstract method, thus making it functional interface.
Great video, loved it. Thank you for explaining the details. Is it possible to implement this structure of group chat with graphical user interface? Actually I tried but I couldn't figure it out. It simply didn't work
Is it a TCP or UDP based communication? Really good Video
hello i have a question, what should i do to make them connect from different pcs and not on localhost. i tried some solutions but it always give me an error
thanks for the video
Hey wittcode, I hope you see this, I loved the tutorial, and you explained everything very well with a hands on approach, but is it possible to run the clients on different computers? If so, how?
i gotchu just run a client-like file on a different computer and use the ip address of your server computer instead of "localhost", also make sure they're on the same network
@@Rohan-Prabhala tysm, so i run the client script and not the client handler right?
@@dabexter client handler works on the server side so that other clients can parallelly work without any error.
@@arunvasunny7386 thank you
@@dabexter have you completed your project?
I have tried to allow multiple instances of my ChatClient class but it isn't working. Can you please help me with this! Thank you!
At 23:40 shouldn't you be doing closeEverything(clientHandler.socket, clientHandler.bufferedReader, clientHandler.bufferedWriter) ? You are iterating through each of clientHandlers, and for each clientHandler, you push the message. Hence if u encounter an exception, you should be closing THAT particular clientHandler's connections. Same logic applies when we are removing the clientHandler from the array. Instead of passing 'this', shouldn't we pass clientHandler?
Hey man... I love your contents. It's so insightful. Thanks. However i can't find the downloadable code on your blog. Can please share?
Heyo, thank you so much for the tutorial!
I have a little problem though. If I close one of the client windows and start a new one. The chat is filled with the word "null" and I don't know what would cause it.
Any idea how to fix it? 😅
Ran into the same issue. The fix is to do a null check for what bufferedReader.readLine() returns in run() method in ClientHandler.java, cuz readLine() will immediately return null if the the corresponding Client program gets terminated.
thank you so much...
Thank you for good educating content. on 21:46, could we use if(this!=clientHandler) {}?
Extremely thankful for helping us in the easiest ways but, if i want to store every one of the texts sent in a file that stays in the "Server" and whenever a new client joins he/she gets all of the messages printed from the file in the console .. to do that what are the changes i should do?
thank you soo much
the client message is not sent to all clients !!