Records In Java - Full Tutorial - The Best New Java Feature You're Not Using
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- čas přidán 17. 04. 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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Congrats on almost reaching 100K. This one should put you over the top.
You are correct!
Please take one class about scanner class..
Thanks
The best person on CZcams 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.
please never stop making videos, these are so helpful!
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!
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.
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.
Explained quite clearly with detailed examples. Excellent tutorial! This is what I needed to start working with Records in Java.
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.
Thanks for teaching me more about records, I was always teaching my fellow programmers about this in my workplace.
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!
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
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.
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!
Great video. Especially for those who know the basics and are interested in new Java Features after J11. Keep these up!
Keep up with the good work, you’re helping a lot of people 🙏🏻
Thank you, I've always wanted to learn about Records.
Guitars 🎸, drums 🥁, and programming. 💻 Yep! You're definitely part of my tribe. Excellent video! Keep it up.
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
Have been following your videos for a while now. Thank you for the awesome content 😊
Nice pace, and super clear, cheers my man
Explanation is clean and clear. please publish more videos like this. Thanks
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.
You helped me understand concepts that was difficult to understand on my own.
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.
You are so underrated! Hope you reach 1 mil subs soon
That's an awesome no BS explanation. Too good.
Your exposition is always so direct and simple. I love it 🙂
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.
Very well explained, readable size text, excellent class! Thank you!
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.
I like the style of teaching, very clear examples and no bs, earned a sub...
Hi John, Please upload Microservices and spring boot tutorials as well
Thanks a lot for doing this tutorial. Clear, easy to follow explanation as always.
Thanks alot John. This talk should be included in the official doc.
Great video, these really helps alot.
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
I was waiting for this video so badly :))
So simple and clear explanation. I really appreciate your help.
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 😉
Nice feature, thanks John for sharing it with us.
Nice content mate, thanks for share!!!
Perfect tutorial, much appreciated!
Thanks bro you helped with my project !
Thanks John, this video really set the Record straight for me!
Great presentation! Thanks!
Wow, awesome video! There are many ways I can think of to use Records.
he best person on CZcams that explains java in such a great way
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"🙂)
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!
Great episode my man!! 😮😮
Amazing bro! Thanks for the info
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?
Great explanation !!! Congrats ....
This is really similar to records in C#. We don't have compact constructors though. I think compact constructors are really neat.
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 . */
@
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!
Very well explained. Thank you kindly.
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.
That's a really good teaching... Thanks 🎉
This is amazing! Thank you :D
Nice and precise explanation without any fuzz 🎉
Love this. Very informative.
Thanks a lot John! Would be there any video about sealed classes? It is also quite cool feature
Good tutorial. I will use this from now on, much more simple way to do the same thing. God bless you.
u have the best java keyword's tutorials, ty
great lesson as always , grettings from Morocco
Beautiful video 💚 thank you 😊
This is sick! I wanted to find this sooner 😥
Hey John, Congrats on reaching 110K, please do videos on java streams, java sockets, Mockito and MVC in the future, thank you
Love you, John. Best teacher.
Omg. You are so amazing at teaching. Thanks Master Yoda
Holy crap, how have I never heard of this? No Java CZcamsr that I've came across has ever mentioned that records even exist. I've always thought they were similar to annotations, so I've never used them.
This removes so much redundant boilerplate from typical one use-data storage classes.
That's because they're a really new addition
Why haven't you just used @Value and @Data until now?
Wonderful explanation! Thank you! Shorty and clear)
Thank you for explaining some unexplored topic
Hi John, you are the best!! please upload Microservices and spring boot tutorials :)
well explained as usual !
I randomly stumbled upon this video and ended up subscribing to your channel :)
Java is usually known for its cumbersome syntax but such awesome improvements like records would make java lovers more excited.
Mindblown by this feature!
Awesome. Thanks.
Interesting feature well explained thank you.
Great explanation
This video reminds me so much of the mCoding video on python Data classes!
Wow that was cool, thank you 😍
Hi i am a french student , we started the poo this week , i think this vidéo gonna help me 😄
Hi John thank Q for ur valuable information sharing love from India 🇮🇳
Looks like Records are like Lombock. I assume they have the same pitfalls you can run into if you are not careful.
But this tutorial was really nice, I haven't touched these yet, but i see for myself already tons of usecases for this.
Especially for like singleton function classes, where you have your builder and then the object that executes said code.
Keep up the work!
It's not as powerful as Lombok unfortunately
@@hellowill But it does not have the same critical performance pitfalls like Lombok has.
And to give context.
In a performance sensitive context lombok has the ability to destroy your performance just based on how the variables are compared in a hashcode/equals function where the order can be important.
@@Speiger Ah right. I guess I dont focus too much on performance critical workloads. I do wish records had better support for builders or so called 'withers'.
@@hellowill Lets put it that way. For people who use lombok its not a great option. For everyone else it is a good way to reduce code and it does reduce the Licensing hell.
@Speiger, @Will - I personally believe java records and lombok are different features that can be used for different things. Records are similar to Lombok's @Value classess, indeed - but Lombok has a lot of other features to offer and it allows much more flexibility.
This is an extremely useful and time saving feature!
I love your videos you're a Hero!
Please, visitor pattern implementation 🙏
Hay John,
Thank you for the great content. You really simplify this. Do you mind covering Executor Service (Multithreading)
Gracias John!!!
thank you for sharing this nice tutorial, keep it up
great video, thank you!