Three Value annotation tricks you should know - Microservice configuration with Spring Boot [05]

Learn about 3 uses of the Value annotation in Spring Boot microservices to access your configuration. Learn how to set default values for configuration when you don't have anything in the property file. Also, learn how to specify lists and map values in your property files and access them as the right data structure in your Spring Boot components without having to manually parse them

#JavaBrains #Microservices #SpringBoot #Configuration #Course

[bqing]

Real talk. This was EXREMELY helpful and helped me figure out an issue I had trying to run a microservice locally. I’m extremely new to coding and this by default gets a subscribe.

[omkarkulkarni]

Hi Kaushik,


For List : although it gives values as [one, two, three]. If you try to print size of list in request handler method you will get 1
Another hint printing list with multiple values would have looked [one, two, three]. i.e. space after each comma

hello Some static message [Mon, Tue, Wed, Thu, Fri]
vs
hello Some static message [Mon, Tue, Wed, Thu, Fri]


Correction:


I used below property in application.properties
weekdays=Mon, Tue, Wed, Thu, Fri


I had to use following code in Rest Controller:
@Value("#{'${weekdays}'.split(', ')}")
private List<String> days;

System.out.println("Number of Days: "+days.size()); added in request handler method printed size =5
In your example it was still printing size=1

[AjayKumar-fdmv]

Excellent, Concise and useful. Thanks

[tejassontakke]

Kaushik has the art of explaining concepts with super simplicity. Thanks, Kaushik.

[istvanolah]

This was very useful, very understandable, thank you :)

[rdnkmr]

Thanks Kaushik, gained knowledge on spel 🙌🏻🙌🏻

[hyperborean]

Dear Koushik,
I have a remark and a question.
The remark: I believe that "#{${dbValues}}" can be simplified as "#{$dbValues}", How do you think?
The question: How would you interpret the following declaration:
@Value("#{$env} == "production"? realService:dummyService}")
Thank you a lot for your wonderful tutorials

[ghury]

hi, thanks for your great tutorials, do you know how to enabled auto run when files are changed? if i go on Settings, all Synchronization section box are selected..

[somnathroy]

I got error when it use
properties file
student.hobbies={indoor: 'reading, writing', outdoor: 'fishing, play'}
and using Controller

Map<String, List<String>> hobbies;
When run application-->
Expression parsing failed; nested exception is EL1043E:(pos 7): Unexpected token. Expected 'rcurly(})' but was 'colon(:)'

[eshgholah]

I have watched many if your tutorials, all of them are good. But I get truly shocked by your endorsement of field injection. It is a NO NO, in the world of real test driven development. Constructor injection is the way forward. 🙏🙏

[kameshnayak]

Please make exception handling with springboot video

[PrasannaLakshmi]

You are simply amazing... Kaushik. I am a fan and consistent follower of your videos. Very very good for beginners and the basics to be strong. Thanks for your willingness to share and exemplary efforts. God bless you.

[vaibhavsarje]

Can you please add video on SpEl also..

[ohhhgggeeezzz]

Does @Value annotation only work on class with @RestController or @Configuration? I have a regular POJO class that I am trying to use @Value annotation to inject values from application.properties but its always null.

But when I move fields with @Value annotation to @RestController it all suddenly works.... am I missing something?

[nishantkr]

Last few lines keeps me engaged and waiting..

[harsha]

Thanks Kaushik. It's indeed a 'value' addition to my knowledge base. :)

[nesreenmohd]

You are always the best in explanation, thank you @Kaushik. Can you please create a series of SpEL! Thanks again!

[howtoed]

Hi kaushik, how about idea of providing same courses on udemy with some price, so that who so ever want to help can buy the courses also.

[bozhang]

Thanks so much! I'm currently doing a ticket about this in work. This is very helpful.

[mohammedshabbirahmed]

You are Awesome Bro You are A Hero You ROCK THE WORLD BRO YOU ARE SUPER AND THE BEST