I cannot seem to make dependency injection work

[nomemory]

I am currently learning micronaut and I wanted to create a simple CRUD application that will take me through all the modules (web, data, etc.). The project link can be found here: https://github.com/nomemory/micronaut-crud-backend .

I have an entity called Book:

@Entity
@Introspected
public class Book {
    @Id
    @GeneratedValue
    private Long id;
    private String title;
    private int pages;
///

A repository for books:

@Singleton
@Repository
public interface BookRepository extends CrudRepository<Book, Long> {
    @Executable
    Book find(String title);
}

And a controller for books:

@Controller("/book")
public class BookController {

    @Inject
    BookRepository bookRepository;

    @Post
    @Produces(TEXT_PLAIN)
    public Long createBook(@Body CreateBook createBook) {
        Book book = new Book(createBook.getTitle(), createBook.getPages());
        return bookRepository.save(book).getId();
    }
}

When I try to access the endpoint http://localhost:8080/book with a POST I am getting the following error:

Caused by: io.micronaut.context.exceptions.NoSuchBeanException: No bean of type [io.micronaut.data.operations.PrimaryRepositoryOperations] exists. Make sure the bean is not disabled by bean requirements (enable trace logging for 'io.micronaut.context.condition' to check) and if the bean is enabled then ensure the class is declared a bean and annotation processing is enabled (for Java and Kotlin the 'micronaut-inject-java' dependency should be configured as an annotation processor).

My investigation lead to the conclusion that the @Inject BookRepository bookRepository; doesn't get injected.

My gradle dependencies are looking this:

dependencies {
    implementation("io.micronaut:micronaut-validation")
    implementation("io.micronaut:micronaut-runtime")
    implementation("javax.annotation:javax.annotation-api")
    implementation("io.micronaut:micronaut-http-client")
    implementation("io.micronaut.data:micronaut-data-jdbc")
    implementation("io.micronaut.data:micronaut-data-hibernate-jpa")
    implementation("io.micronaut:micronaut-inject")

    compileOnly("org.graalvm.nativeimage:svm")

    runtimeOnly("ch.qos.logback:logback-classic")
    runtime("com.h2database:h2")
    runtime("io.micronaut.sql:micronaut-jdbc-tomcat")

    annotationProcessor("io.micronaut:micronaut-graal")
    annotationProcessor("io.micronaut.data:micronaut-data-processor")
    annotationProcessor("io.micronaut:micronaut-inject-java")
}

Any ideas & suggestions or another sample repo where I can get inspired from ?

[graemerocher]

Micronaut Launch is a great reference for how to get setup properly and get your application correctly configured.

1. Create the project

$ mn create-app jpa-example --features data-jpa
$ cd jpa-example

or

$ curl https://launch.micronaut.io/jpa-example.zip?features=data-jpa -o  jpa-example.zip
$ unzip  jpa-example.zip -d  jpa-example
$ cd jpa-example

2. Create en entity:

touch src/main/java/jpa/example/Person.java

Modify content to:

package jpa.example;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Entity
class Person {
    @Id
    @GeneratedValue
    private Long id;
    private String name;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

3. Create a repostory

$ mn create-repository person

4. Modify Test to

package jpa.example;

import io.micronaut.test.extensions.junit5.annotation.MicronautTest;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.Assertions;

import javax.inject.Inject;

@MicronautTest
public class JpaExampleTest {

    @Inject
    PersonRepository repository;

    @Test
    void testItWorks() {
        Assertions.assertEquals(0, repository.count());
    }

}

5. Run tests

./gradlew test

[nomemory]

@graemerocher thanks for the quick reply.

Can I use the mn to update an existing project ? Or it's only for creation ?

---

I've created a project as you described above, and I saw that the dependencies generated similar to the dependencies from the project I am referring to: https://github.com/nomemory/micronaut-crud-backend .

Do you have any idea what I am doing wrong ?

[graemerocher]

your application.yml is missing any kind of db configuration so that is probably it

[nomemory]

The application.yml contains the following:

datasources:
  default:
    url: jdbc:h2:mem:devDb
    driverClassName: org.h2.Driver
    username: sa
    password: ''
    schema-generate: CREATE_DROP
    dialect: H2

jpa:
  default:
    entity-scan:
      packages: 'net.andreinc.mn.crud.backend.*'

[graemerocher]

Sure but it is in the wrong place. As I said I really recommend you follow the instructions I described above to get setup as the majority of problems like this are user error / configuration problems.

[nomemory]

@graemerocher yes you were right. I've copied pasted the configuration files from the generated project in my project and things are working properly now. Thank you for your patience.