Spring Boot Dependency Injection - What Is It? Tutorial and Example

Thanks sir! I respected your explanation

Methods with capital letters... the level of degeneration our society is reaching is alarming.
Anyway, good tutorial!

Thanks for explaining this rather simply, but I think the last part of the video counters the use of DI completely. If you use an abstraction in a class but you need need to provide a qualifier with it that matches the one of the implementation you want then it basically is equivalent as new-ing the implementation up in the class directly. Your class is now directly tied to the implementation through its qualifier which is precisely what we try to avoid with DI and IoC. The class shouldn't be responsible of this, it should be configured elsewhere.

I still don't understand why this is better. "Hey look, we're doing something that will save you one line of code...minus the 2 lines of annotations it adds, but every once in a while it'll save you two seconds.....just forget about the 5 days you've wasted trying to figure out how to structure your program when your normal Java object constructors that perform required initialization of objects fire off multiple times for some unknown reason." I really wish people would stop "saving me time". :D I like how easily I can spit out code to a web server using the controller, but this stuff along with normal java event handling not working and multithreading being done differently...I feel like I'm wasting my life with all the "time savings."

u r just awesome with the examples

dude.... you were doing so well, but totally missed the climax. There's no difference in your story between DI and explicitly instantiating one class or the other. You're misleading the noobs...

Thank you, cleared things for me.

Best Video on Dependency Injection. TY

Great video ! Solved a lot of my struggles with dependency injection.

Use lombok RequiredArgsConstructor and declare dependencies as private final

the interface does not have to be a Component

thanks

This is very helpful! Thank you

Really good!! Thx a lot.
Stay safe.

I don't believe you have explained what happens at the background properly.

This is counterintuitive. Why do you decorate a field with @Autowired and then assign a value to it in the constructor anyway? If it should be autowired then why do you wire it yourself? Also I wouldn't call wireing a field dependency-injection. It's rather dependency-hacking. How would you override this for testing when it's virtually a hardcoded dependency?

Terrible explanation tbh. Showing a stackoverflow post instead of providing some basics? 5 minutes into the video and nothing related to dependency injection?

Am I the only one who finds it irritating that he is starting his method names in capital letters?

Very good explanations for Dependency Injection in Spring Boot. thanks

good, helped me a lot.

useless

I still have no clue how is that useful? doesn't that still instantiate a object of textwriter?(maybe not by your hand but I'm sure it will be instantiate in the background.

good tutorial

Hey Erik, what do i do if i have a Component that has a parameter in its constructor? For example a String. How can i account for this paramter in my RestController class when i AutoWire the Component?

Awesome explanation of dependency Injection! Ultimately I got some source where explanation is clear without confusion! Thank you.

Caused by: java.lang.ClassNotFoundException: org.springframework.boot.context.event.ApplicationStartingEvent


why i getting this error?

great tutorial

Hey Erik this is just amazing. Can you please do a video on the getBeans method?

where are the next parts:? What do you mean by @Component?

Thank you for this! Makes so much more sense now!

Thank you I found this very useful!

This video was gold! I was beginning to think I would never understand autowiring. Thank you!

It was difficult for me wrapping my head around using the applicationContext.xml to configure the DI

Thank a lot Erik, this just made setter injection easier

Hey Erik, thanks for this post! Great example for the @Autowired and @Qualifier!

Great video man! thanks for taking the time to show us.
Cheers from Guadalajara

You know IntelliJ has auto save right? Also day mode eww

Awesome!

write methods with first letter Caps wtf?

Thank you for the video. Can you please create a video on how to pull data from sql and display on the UI?

Thank you

thanks a lot! :)

Thanks! Well explained.

It's better to use constructor injection for testability. Your methodnames also need to start with a small letter

Thanks, Erik, nice lesson! Keep them coming. :)