Records In Java - Full Tutorial - The Best New Java Feature You're Not Using
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- เผยแพร่เมื่อ 17 เม.ย. 2022
- How to use Records in Java!
Complete Java course: codingwithjohn.thinkific.com/...
Records are a new concept added to the Java language as a preview feature in Java 14, and in a full release in Java 16. In this intermediate Java programming tutorial, we will talk all about when you would want to use Java records, and exactly how to do it.
If you're confused by records in Java, you're in the right place!
Learn or improve your Java by watching it being coded live!
Hi, I'm John! I'm a Lead Java Software Engineer and I've been in the programming industry for more than a decade. I love sharing what I've learned over the years in a way that's understandable for all levels of Java learners.
Let me know what else you'd like to see!
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The best person on TH-cam that explains java in such a great way
If you didn't see anyone better doesn't mean he is the best ;-) He is good anyway.
@@pavelsakun2308 this is my opinion and l am free to think whatever I want right ;)
you were the reason i got a 5 on my ap comp sci A exam!! you truly have impacted my education and taught me more than my highschool teacher did in 5 months !
Awesome, and congrats!
Funny, 5 would be an E in Germany. Had to think about that for a second.
It’s 5/5
@@Reichstaubenministersprach der reichstaubenminister
I recently found out about Records but there are just no good tutorials about it. I'm glad you made one now.
Thanks! Yeah there's surprisingly little out there so far. Probably just because it's pretty new.
Congrats on almost reaching 100K. This one should put you over the top.
You are correct!
Please take one class about scanner class..
Thanks
please never stop making videos, these are so helpful!
There is a lot of content like this out there, but you are so much better than the rest in terms of tempo, order, quality and presentation, thank you so much! I started studying CS half a year ago and your videos are 5x quicker at explaining the same thing than my prof. Although sometimes there is some depth missing, but it's good that your videos don't get lost in that, that's what makes it so good. Maybe it would be great if there was a playlist for in depth knowledge as well though.
Quality, effective, efficient and much appreciated content.
I am advanced in java but it is great to see someone explain it so concise. Amazing explanation on these types of videos. Keep it up!
Could you do a video on Consumer, Predicate, and Supplier? I mostly understand what they do, but not when to use them.
if you are reading this John, please make this video happen! Thanks!
Explained quite clearly with detailed examples. Excellent tutorial! This is what I needed to start working with Records in Java.
Thanks for teaching me more about records, I was always teaching my fellow programmers about this in my workplace.
Never thought learning Java would be such a pleasure. A decade ago, I was frustrated with the Java Reference book and left learning java and continued with my day job in DB language. Now, I am learning java without any issues with the help of youtube. Thanks to the youtube community.
Hi John. Even when i write Java programs quite a while, i still learn new thing from you. Thank you, you are presenting good Java content. Kind regards, Simon Rozendal.
I've been learning Java in my CS degree for the last three years, I had no idea records were a thing!!! So cool!
Yep! They're a relatively recent addition.
Not a Java developer but I have to read Java and Groovy all the time. Your videos are great background to help me understand what I’m looking at. Great stuff.
Great video. Especially for those who know the basics and are interested in new Java Features after J11. Keep these up!
awesome as always, thank you for sharing man, I am familiar with records but I'm not aware that I can do specific field validations directly into it, that's very useful thanks man
Thanks John!!! Always looking for ways to improve and writing clearer/better code.
Side Note…are you using Java 17 or 16? B/c “records” is not supported in Java 11.
I thought I knew all about records (and I am using those extensively) but this is the first time I heard about the compact constructor! Thanks a lot!
The way of teaching is totally different.. thank you so much for the deep knowledge that you are sharing... kindly make tutorial on stream api in future
At 5:00 you mention that Java generates a default, no-arg constructor *even if* you don't create other constructors. That isn't quite true, Java creates a no-arg constructor *only if* you don't create other constructors. This is why your fields get red underlines as soon as you manually create the no-arg constructor, because there would be a way to have final fields that aren't initialized as soon as the object is created. Before you manually created the no-arg constructor this wasn't a problem, because Java wouldn't generate one since you already had the previous one created.
That's absolutely true, maybe it was just a runtime exception(subclass of Exception) at his speech. lol
I don’t get what you mean. I feel like your comment just justified what he said. Or do you think he meant even if you have other constructors Java always generates a default no-arg constructor? I think he just put it there for visuals of a no-arg constructor. Because i got that what you said from the video.
@@KaraSuraDraw1 He said that Java provides a no-arg constructor no matter what constructor you already have definded. That's not true.
When you create an object of the Class two things happes: 1. MEMORY IS ALLOCATED, 2. THE CONSTRUCOR IS CALLED. By default Java offers a 0 argument construcotrs which are 0 for numeric types, and false for boolean and null. The moment we create our impemtation of constructor ( a constructor which initialize fields) the 0 arg one is no longer called.
True , if you have created just an args-constructor ;
You cant created object as : new Employee();
That means Employee class doesn’t have no arg constructor ;
You have to create one.
Thank you, I've always wanted to learn about Records.
Thank you so much. This was very helpful and the way you explain things makes it so easy to understand them. Keep up the good work, John!
That's an awesome no BS explanation. Too good.
Keep up with the good work, you’re helping a lot of people 🙏🏻
Explanation is clean and clear. please publish more videos like this. Thanks
Hi John,
Thank you for your superb content. Me and other group of people from Estonia are learning Java and your channel helps us to understand hard material in a simple way.
Could you please make a video tutorial about streams in future?
Thank you in advance,
Tony
Nice pace, and super clear, cheers my man
Your exposition is always so direct and simple. I love it 🙂
Have been following your videos for a while now. Thank you for the awesome content 😊
I like the style of teaching, very clear examples and no bs, earned a sub...
You helped me understand concepts that was difficult to understand on my own.
Thanks alot John. This talk should be included in the official doc.
Very well explained, readable size text, excellent class! Thank you!
Hey John!
If i knew Records before, i would use them in my previous task in my company because they fitted my task perfectly!
Thank you for your effort :)
your videos really help me to focus on Java again :)
Thanks for the Video John! Greetings from Brazil 😉
Great video, these really helps alot.
So simple and clear explanation. I really appreciate your help.
Hello John,
it's always great to listen to your explanations on Java! Thank you for your valuable wisdom!!
On a side note, noticed your voice and the way you talk has changed since you become a father :)
Hope you and your family well during this different times!
Keep making thus great videos, always love watching them!
Guitars 🎸, drums 🥁, and programming. 💻 Yep! You're definitely part of my tribe. Excellent video! Keep it up.
Thanks a lot for doing this tutorial. Clear, easy to follow explanation as always.
really cool!!!
Spring had some simplification,
but here it's much better and has also interesting options!
Thanks 👍👍
What do you mean by the Spring simplication?
Perfect tutorial, much appreciated!
Nice feature, thanks John for sharing it with us.
Great presentation! Thanks!
Great explanation !!! Congrats ....
Thanks a lot John! Would be there any video about sealed classes? It is also quite cool feature
Great episode my man!! 😮😮
I've watched all of your videos and they r really really helpful and easy to understand, seriously.. u're an amazing teacher and I wish all success for u and ur channel.
Small demand: I'd like to learn about Streams in ur way the next tutorial, if that's fine, however, any tutorial u make wod be awesome.
Thx man, you're LaJend (J refers to "Java legend"🙂)
Nice content mate, thanks for share!!!
This is really similar to records in C#. We don't have compact constructors though. I think compact constructors are really neat.
Hi John, Please upload Microservices and spring boot tutorials as well
Thanks bro you helped with my project !
I cannot believe I completed many courses and projects in Java without using this 😔🤯 My goodness, think of the time I could've saved! Thank you for making this video. It's so engaging, informative, and very easy to understand.
That means, that this stuff is not really important. It is not a unique cure to any problem you had.
after i am learning about memory management, stack and heap and jvm internals i could really understanding this properly what a powerfull feature
Thank you so much , explaination was very nice.
Amazing bro! Thanks for the info
Very well explained. Thank you kindly.
Wow, awesome video! There are many ways I can think of to use Records.
u have the best java keyword's tutorials, ty
I was waiting for this video so badly :))
That's a really good teaching... Thanks 🎉
Mindblown by this feature!
Java is usually known for its cumbersome syntax but such awesome improvements like records would make java lovers more excited.
Love this. Very informative.
Love you, John. Best teacher.
You are so underrated! Hope you reach 1 mil subs soon
Good tutorial. I will use this from now on, much more simple way to do the same thing. God bless you.
Gracias John!!!
Wonderful explanation! Thank you! Shorty and clear)
This is amazing! Thank you :D
Nice and precise explanation without any fuzz 🎉
Thank you sooooo much!
Hey John, Congrats on reaching 110K, please do videos on java streams, java sockets, Mockito and MVC in the future, thank you
great video, thank you!
@
Coding with John , Hi, could you please record a video about Java 8 features like Optional and Streams. It will be so wonderfully. And big thank you for short and really useful videos!
Beautiful video 💚 thank you 😊
This is sick! I wanted to find this sooner 😥
he best person on TH-cam that explains java in such a great way
great lesson as always , grettings from Morocco
Omg. You are so amazing at teaching. Thanks Master Yoda
Thank you brother!
Tip: If you want to store mutable objects in records:
public record EmployeeRecord (java.util.concurrent.atomic.AtomicReference name, int employeeNumber) {} /* Here, _only the value of AtomicReference name_ (a String) is mutable; the value can be changed with employeeRecord.name().set("John"); and can be gotten with employeeRecord.name().get(); */
(or)
import java.util.concurrent.atomic.*;
public record EmployeeRecord (AtomicReference name, AtomicInteger employeeNumber) {} /* Here, _both_ the values stored by name and employeeNumber (String and _int_ respectively) are mutable. The value of employeeNumber can be changed by employeeRecord.employeeNumber().set(x); (x must be an int or an Integer (if it is an Integer, it will be unboxed)) and can be gotten with employeeRecord.employeeNumber().get(); */
/* FAQ: employeeRecord.employeeNumber().get() returns a variable of type int (may autobox to Integer). If employeeNumber is to be directly of type Integer, it should be declared as java.util.concurrent.atomic.AtomicReference employeeNumber . */
well explained as usual !
Except for that neat overriding constructor, it seems like Lombok is still a more useful option, unless you can put annotations on the fields declared in record for things like JPA or JSON serialization
what is Lombok?
@@Darya-pu6ik It's a library that allows you to use annotations in order to create things like getters, setters, equals methods, etc.
For example, instead of write getters and setters you just use the annotation @Data, @Getter or @Setter above a constructor:
@Getter
@Setter
public Car(String color, String name) {
}
@@ThiagoHenriqueDS thanks, looks helpful!
Lombok is indeed very useful but it still a third party plugin. Java is usually known for its cumbersome syntax but such awesome improvements like records would make java lovers more excited.
Seeing comments like this makes me think other devs are spending a lot of time to generate POJOs/DTOs and that's hardly true. That kind of objects is being written once and the rest 99+% of time is spent for writing business logic, so even with what vanilla java and IDEs are providing I do not see HUGE problem of implementing them without record/lombok. The only exception here is readability, but...do you really often open classes named '*DTO" for reading? I really doubt.
Hay John,
Thank you for the great content. You really simplify this. Do you mind covering Executor Service (Multithreading)
Thank you a lot!
Thank you for explaining some unexplored topic
thank you so much for your videos
Hi John, you are the best!! please upload Microservices and spring boot tutorials :)
Great explanation
This is an extremely useful and time saving feature!
Very Informative
That is very useful!
Very informative 👏
Hi John thank Q for ur valuable information sharing love from India 🇮🇳
Perfectly explained.
Excellent video
That's similar to class declaration in Scala, except that there you can simply specify var or val in front of field name to make it either mutable or immutable. Or make it a case class with immutable fields by default. But in Scala, there is no need for that "compact constructor" because you can write any validation code directly inside the class body.