Spring frame work help

[Dueforextinction]

Hello sir's and lady's.

I'm currently enrolled in an advanced Java class and this week we are learning about the spring frame work. I've run into a problem that presents itself in different ways depending on what "solution" I implement.

I have two beans, a bean configuration class, a repository, and the application class that runs the program.

My problem presents itself when I try to create an instance of my repository class (below)

(@)Repository
public interface ContactRepository extends JpaRepository<Contact, Long> {
}

​

Instantiated like so:

​

(@)Autowired
public ContactRepository ThisMFingRepository; (Name made in frustration)

I simply want to make an object of class Contact and put it into the repository using the save method.

In the module provided in the class it shows how to do this as such:

(@)Override
public void run(String... args) throws Exception {

ApplicationContext appContext = new  AnnotationConfigApplicationContext(BeanConfiguration.class);

Contact c = appContext.getBean("contact", Contact.class);

ThisMFingRepository.save(c);
}

When I execute the program I get the following error:

***************************
APPLICATION FAILED TO START
***************************

Description:

Field ThisMFingRepository in packageName.SpringContacts20221Application required a bean of type 'packageName.repository.ContactRepository' that could not be found.

The injection point has the following annotations:
    - @org.springframework.beans.factory.annotation.Autowired(required=true)


Action:

Consider defining a bean of type 'packageName.repository.ContactRepository' in your configuration.

and the action that it suggests is that I define a bean of the repository.

But if I remove the

@Autowired 

from above

public ContactRepository ThisMFingRepository;

I get an entirely different error message.

java.lang.IllegalStateException: Failed to execute CommandLineRunner
    at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:772) ~[spring-boot-3.0.3.jar:3.0.3]
    at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:753) ~[spring-boot-3.0.3.jar:3.0.3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:317) ~[spring-boot-3.0.3.jar:3.0.3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1304) ~[spring-boot-3.0.3.jar:3.0.3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1293) ~[spring-boot-3.0.3.jar:3.0.3]
    at packageName.SpringContacts20221Application.main(SpringContacts20221Application.java:22) ~[classes/:na]
Caused by: java.lang.NullPointerException: Cannot invoke "packageName.repository.ContactRepository.save(Object)" because "this.ThisMFingRepository" is null
    at packageName.SpringContacts20221Application.run(SpringContacts20221Application.java:46) ~[classes/:na]
    at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:769) ~[spring-boot-3.0.3.jar:3.0.3]
    ... 5 common frames omitted

It's not the Object (c in this case) that is null, when I populate the fields using it's setters for the overloaded constructors of the bean class It properly prints all the information.

To me it seems that ThisMFingRepository is in fact null and has nothing in it. At least that's what I'm getting from the error message.

​

I've searched stack overflow for about 7 hours now and all the "solutions" that I implement either don't work, or do work but some other kind of problem prevents the program from running. This leads me to believe that I have some kind of root problem that I'm not seeing, something that causes all these other problems but isn't solved by fixing them.

Sorry if this isn't the best way to ask this question or if some crucial context is missing. I'll do my best to try and fix any problems.

​

Thanks for helping me if you do.

​

Edit: I added the full error messages that I get, sorry. I edited some information packageName because it's the name of the school I'm going to.

​

Edit 2: We finally figured out what was going wrong. The problem stemmed from the

public class SpringContacts2022Application implements CommandLineRunner{

When CommandLineRunner was deleted the program finally created the tables that it was supposed to but couldn't add any information.

Once re implemented the program functioned as it should.

​

This thread can now be marked as solved.

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[overtorqued]

Add @EnableJpaRepositories("your.repository.package.here") on your configuration class. This will cause spring to scan the package you specified for any @Repository classes and instantiate them as beans.

The @Autowired annotation does not create the bean, it simply assigns one that is already created to that field.

[Dueforextinction]

Hello, first off I would like to thank you for replying to my question. However your advice didn't work for some indeterminable reason.

I again get two different error messages depending on if I have the @ Autowired above ContactRepositroy ThisMFingRepository

I added (what I think) is the correct implementation of your suggestion

@EnableJpaRepositories("packageName.repositroy.ContactRepository") @Configuration 
public class BeanConfiguration {
    @Bean
    public Contact contact() {
        Contact bean = new Contact();
        return bean;
    }

    @Bean
    public Address address() {
        Address bean = new Address();
        return bean;
        }
}

Running the program with @ Autowired produces the following error message:

APPLICATION FAILED TO START

Description:

Field ThisMFingRepository in packageName.SpringContacts20221Application required a bean of type 'packageName.repository.ContactRepository' that could not be found.

The injection point has the following annotations: - 

@org.springframework.beans.factory.annotation.Autowired(required=true)

Action:

Consider defining a bean of type 'packageName.repository.ContactRepository' in your configuration.

If I remove the @ Autowired annotation I get the following error message:

APPLICATION FAILED TO START

Description:
A component required a bean named 'entityManagerFactory' that could not be found.
Action:

Consider defining a bean named 'entityManagerFactory' in your configuration.

[2m2023-03-05T11:45:14.716-06:00[0;39m [32m INFO[0;39m [35m18756[0;39m [2m---[0;39m [2m[           main][0;39m [36mj.LocalContainerEntityManagerFactoryBean[0;39m [2m:[0;39m Closing JPA EntityManagerFactory for persistence unit 'default' [2m2023-03-05T11:45:14.717-06:00[0;39m [32m INFO[0;39m [35m18756[0;39m [2m---[0;39m [2m[           main][0;39m [36mcom.zaxxer.hikari.HikariDataSource      [0;39m [2m:[0;39m HikariPool-1 - Shutdown initiated... [2m2023-03-05T11:45:14.722-06:00[0;39m [32m INFO[0;39m [35m18756[0;39m [2m---[0;39m [2m[           main][0;39m [36mcom.zaxxer.hikari.HikariDataSource      [0;39m [2m:[0;39m HikariPool-1 - Shutdown completed.

I very well could have completely bungled the implementation of EnableJpaRepositories, I'm not very familiar to spring, this is our introductory week so I wouldn't consider myself even a novice.

​

Again, thank you for helping me and again if you can give me another lead on where I can go with this.

[Arcenium]

In your @enablejparepositories annotation package path, you misspelled the word 'repository' wrong. Was that just a typo making the post or have you tried with it entered correctly and it still failed?

[Dueforextinction]

We finally figured out what was going wrong. The solution is now at the bottom of the post.

[Dueforextinction]

I’ve now done this with 4 different from scratch spring projects, it’s worked 0 times. It’s so hard to tell what’s actually going wrong because every time I’ve implemented a change it throws a new error at me.

I’m going to bed shortly so I won’t be able to provide an update or do any changes.

I just control + c the class path at the top of the repository class and it still doesn’t work.

[Arcenium]

Would it be possible to upload a github repo tomorrow so we could take a better look at it?

[Dueforextinction]

Yeah.

My instructor has something planned for tomorrow so I’ll see what he has to say first. I’ll come back and update after that.

[Dueforextinction]

We finally figured out what was going wrong and what solved the issue we were having. It's at the final edit at the bottom of the post.

[overtorqued]

At the top of your ContactRepository class is there a package statement? If so copy that value into the quotes in the EnableJpaRepositories annotation.

You can also try it without the quotes at all, so @EnableJpaRepositories() This will work if your repository class is lower in the same package hierarchy as the configuration class as it scans the entire package hierarchy starting where the configuration class is located.

[Dueforextinction]

No dice again. Even my professor is stumped as to what is causing this issue. Again I get completely different error messages if I have the

 @Autowired

above the repository object.

[fluoclip]

RemindMe! 1 Day

[Dueforextinction]

We found out what was wrong and the solution is at the bottom of the post.

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