Dependency injection from Quarkus (java)

Question

Colleagues, hello! Is is possible to inject beans inside of class which is created via 'new' operator? For example:

public class TestClass implements Callback {
 
@Inject
TestClassRepository repository;

//just only methods...
}

And 'TestClass' is created from another class:

Flyway.configure().collbacks(new TestClass()).load();

I have an issue with this,because 'repository.anyMethods()' inside of TestClass creates 'NullPointer' exception. 'TestClassRepository' is marked with the '@ApplicationScoped' and '@Startup' annotations.

Answer 1

@Singleton
public class TestConfig {

  @javax.enterprise.inject.Produces
  public TestClass testClass() {
    return new TestClass();
  }
}

another class annotated with the @ApplicationsScoped or @Singleton:

@Inject
public void method(TestClass testClass) {
  Flyway.configure().collbacks(testClass).load();
  // your code
}

If you create an object by yourself calling a constructor (new TestClass()) then quarkus doesn't manipulate that object, and doesn't inject a repository.

Answer 2

No you cannot inject beans inside a class that is instanciate with the new keyword. But you can still find a way around like so :

@Dependent
public class BeanFactory {

  @Inject
  TestClassRepository repository

  @Produces
  public TestClass createTestClass() {
    return new TestClass(this.repository);
  }

You can find more details here : Quarkus Contexts and dependency Injection

Also you can define multiple beans for different profiles as mentionned few lines bellow Here

This means you can create a repository for your tests and one for prod or whatever is best for your case.

Also I do not think the annotation "@Startup" would add anything to your TestClassRepository bean.