Java Socket Programming - Multiple Clients Chat

[@f3sa899]

I think this is the best video on KZbin about I/O streams and sockets.

[@bernardkingsley8598]

Is there any way I can see your code

[@amc1140]

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!

[@WittCode]

Thanks so much man! Also love your taste in music haha 🎸

[@amc1140]

@@WittCode hell ya Java and Punk Rock are a 90s dynamic duo🤘

[@og_yamiatan3957]

@@WittCode can i make those names of clients in diferent color ?

[@Rohan-Prabhala]

@@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

[@uuo4930]

This truly explains everything so clear, thanks man

[@cybernetic777]

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.

[@GiyuTomiokaTheOneAndOnly]

This dude literally explained my entire 5 months course in a 40 minute video

[@weaponkid1121]

Haven't even finished the video yet but I'm happy I found this channel!

[@xxx4am]

Thank you WittCode , you have just earned a new subscriber. I cannot begin to explain how helpful and useful your videos are especially this one. I am a software engineering student and I can safely say that this one video is more useful than my entire Java programming class.

[@WittCode]

😀

[@cristiangligan-ignatescu771]

Thank you so much dude! Consider becoming a teacher in the future 🙏 You have that pedagogical talent :)

[@MostafaMahmoud-cj2sh]

IT WORKED, THANKS I'VE BEEN LOOKING FOR THIS FOREVER, BUT NO TUTORIAL COULD EXPLAIN IT AS YOU DID

[@imanjallali8258]

Let me just tell you one thing. Thanks for Being in KZbin to share content most are not capable of doing.

[@WittCode]

Thanks so much!

[@romanzdev]

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.

[@pawe7420]

Wow man, you really clearly showed how to make such chat in Java, thanks a lot! :)

[@UninspiredFilm5]

THIS IS SO COOL! And I managed to reinforce sockets, IO, AND threads ALL AT ONCE

[@jadabouzeid9165]

Thank you so much for this video! Very well explained, it helped me a lot for my university project.

[@irinatrandafir7390]

You explain everything so well and simple ♡

[@freddiewittmann1494]

Great work! I love the thumbnail! So many WittCodes!

[@WittCode]

Thanks for the support Freddie! 😎

[@spenzr6920]

So underrated!!! I wish you'll gain more subscribers and viewers. Amazing video

[@jackinquisitor9645]

Thx for your tutorial, I finally understand how socket work

[@wenwengalarpe14344]

I understand all men you're a great teacher!!

[@harrygabbi5181]

great video thanks for making it i was stuck on this for so long

[@maxhitmemedi6598]

You are a lifesaver man, thank you a lot you are saving me a ton of hours and nerves :)

[@mosesfrancis4976]

This is what, I looked for in Java. Thank you so.

[@oveezion]

Lowkey saved my uni lab work xd , keep up the good work !!

[@martingogaming1777]

Thank you, I had trubles with sending message to multiple clients, because of reading system input, thanks again!

[@WittCode]

Hey there thanks so much! Yeah the reading input part tripped me up for a while too! 😃

[@motodankz4838]

Wow you are suck a great teacher. You explain every step. Thank you so much!

[@tungle3635]

thank you so much, this content deserves much more credit

[@WittCode]

Thanks so much! That means a lot! 😃

[@kevincianci5443]

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.

[@WittCode]

Thanks so much Kevin! And I will certainly be making a GUI version of this! Probably using JavaFX 😀

[@vikaskotwani9573]

@@WittCode , hey witt please do that asap

[@bhpure30]

great video, wonderful explanations throughout too.

[@WittCode]

😀

[@g.722]

Very helpful! Thank you so much!

[@borissmax3]

Thank you! Learned a lot from this

[@premkarki2]

Thank you for the clear and concise explanation. I just subscribed you. I wish to watch your more videos.

[@WittCode]

😀

[@Tygelin86]

Great tutorial!

[@uzumakiuchiha7678]

Nice one man. Keep it up!

[@rnyah_]

I'm so grateful to you, this really so helpful man thank you so much

[@mc_mzcgt]

Thank you so much!!! This is what I was finding!

[@arthurbakker740]

Great content, learned a lot!

[@bernardkingsley8598]

Is there anyway I can see your code by chance, that is if it's working

[@haris7521]

This is simply awesome man 👍❤️

[@angelinawho5551]

You are lifesaver man, thank you a lot :)

[@adwa1888s]

thanks a lot bro, keep the good job.✌

[@nadiiar75]

Greetings from Ukraine! You are awesome! Thank you so much for this great tutorial. It helped me a lot.

[@akalankaalutwela7712]

Thank you very much for this!

[@charlesjaussaud1822]

your video is awesome and helped me a lot. thank you.

[@vasantpatel9297]

this is briliant my friends thank you so much

[@sahilbhirud1301]

Love the thumbnail hahah

[@WittCode]

Sahil! Good to hear from you man! And yeah I thought it was the coolest one Ive made so far lol

[@replikvltyoutube3727]

This helped me a lot, thanks!

[@chetan788]

video is very helpful. Thank you.

[@0brooo]

I took a server side approach instead of a client side approach, love the video tho, thank you

[@hvasomhelst]

thank you so much, saved my homework truly!

[@ayushsharma4618]

bro can you send code please

[@mihaioprea9398]

Great video! Really helped!

[@freddierobinson9587]

this was perfect for me thank you

[@m4rt_]

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.

[@antrancaobao7110]

yah it sounds correct

[@kurwa_mach]

Thank you very much, man

[@sirojiddingroup]

Thanks bro it has been very usefull for me

[@karolinemalko1723]

thank you! Subscribed!

[@yashwanth7978]

Can you share the code, not able to find in the link you kept in description

[@johnnys.828]

Thank you very much!

[@aladin7339]

thank uuuuu so much, this is so helpful

[@AlexKayzProductions]

Great tutorial, thanks

[@elifkaragoz2606]

Which design patterns are we using in this program and which pattern I can implement into the code in addition to develop the code?

[@Asswipe69]

Nice tutorial man, rly need something like tihs :D

[@WittCode]

Thanks so much! Also, love your username lol

[@long3850]

very helpful video !

[@damiaotiktok023]

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

[@feuerherz007]

Hello sir. Is the code still on your website? i can only seem to see some Javascript. Is it on a github page?

[@siradjeddinefisli1440]

the client message is not sent to all clients !!

[@heshakarathnasekara7135]

awesome video i love it thankyouu

[@mahamatmahamatabdoulaye893]

Many thanks Sir 😘

[@3umaryy]

Why we can't run the server again? After it being in use? Like turn off the server and Re-open it.

[@elishaamenuveve4307]

Great video!

[@ambawadisu2050]

Thank you man, is that possible to chat only with one person from the group please share if you have such kind of code

[@patsondamascus885]

i tried it it works but my message dont appear to other clients it only appears in my chat only not other chats'

[@Jaa1711]

Thank you so much..!

[@WittCode]

😀

[@dabexter]

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?

[@Rohan-Prabhala]

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

[@dabexter]

@@Rohan-Prabhala tysm, so i run the client script and not the client handler right?

[@kutayyaman]

thanks for the video

[@fabiansvensson9588]

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!

[@ngocminhpham1358]

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

[@fabiansvensson9588]

@@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.

[@ngocminhpham1358]

@@fabiansvensson9588 thanks a lot!

[@sankarphat]

@@fabiansvensson9588 Oh my god i was desperate while seaching the solution and boom i found your comment. You're a god.

[@lara564]

at which line do you add this "if(messageFromClient == null) throw new IOException();" ?

[@15iunie94]

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)

[@danielluo6499]

great channel

[@RNDev666]

tysm for this video! its great! one question tho.. at 21:14 couldn't you check if this!=clientHandler?

[@WittCode]

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! 😄

[@RNDev666]

@@WittCode yeah i was wondering abt duplicate usernames lol

[@vedant5541]

thank you so much...

[@sebastiangard18]

Is it a TCP or UDP based communication? Really good Video

[@user-hr3wf9rn9o]

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 !😍

[@kutilkol]

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.

[@morgard211]

Shouldn't we rather use AtomicReferenceArray for the clientHandlers to avoid race conditions since more thread access it?

[@romanzdev]

You are correct, use thread-safe collections or manage synchronization

[@americancitizen748]

Very good!

[@HAZARD_LIGHTS]

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.

[@WittCode]

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! 😀

[@HAZARD_LIGHTS]

@@WittCode Thank you so much, I really appreciate you taking the time out of your day to respond to my request!

[@m.misbahalizada9837]

thank you soo much

[@vishnusudarsanam5375]

Real gem!!

[@aladin7339]

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

[@or-abylaikhan]

nice tutuorial man and one silly question "can I connect to that server from another PC?" Or it works only local host?

[@supercrusher1235]

I searched your blog but the code isn't there.

[@AlthonJohnson]

Dope, This was really very helpful.

[@WittCode]

That's great to hear Althon! Thanks for watching! 😀

[@noobmaster0810]

can the client use anathor computer like LAN ???

[@bobfarker4001]

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?

[@peterlingas7843]

Thank you so much for this! I'm new to Java and want to make a chess game that can connect to another PC. Would love to see a video with a UI!

[@WittCode]

Thanks for watching Peter! I am currently working on that video so I should have it up soon! 😀

[@peterlingas7843]

@@WittCode Looking forward to it! Waiting for the bell to ring.

[@peterlingas7843]

@@WittCode Also, how would I go about hosting a server that any computer can connect to? Is there more to it than changing the "localhost" parameter?

[@hplat-vku]

thank bro ,

[@WittCode]

😀

[@wenwengalarpe14344]

Helpful video thanks for making this. Can you do a server PC and a client mobile phone.

[@Gandeon1]

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? 😅

[@zhonglin5985]

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.

[@ismailgunduz7]

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

[@nordeenhasan6030]

Thanks alot

[@frankheinzelmann7547]

How can i start it in the console like you did at the beginning of the Video? And is it possible to cumunicate with friends on other pcs in the same Network And how? I really love your video 👍

[@WittCode]

Hey again! You can start it in the console by navigating to the folder where the .java files are and then compiling them with javac filename.java and then running it by just java filename. And if they are on the same network they just need to run a client script where the socket connection has the ip address of the server!

[@kutilkol]

beautiful! thanks! (do more java tutorials pls