Autowired spring boot in Jframe

Question

In the development of a Spring Boot application for Desktop, it is possible to inject a @Repository in a class JFrame?

If yes how? Some alternative?

Code examples:

@Repository
public interface ItemRepository extends CrudRepository<Item, Long> {}

public class ItemFrame extends JFrame {

    @Autowired
    private ItemRepository repository;

}

That code gives NullPointerException, I tried to write down the class with @Component and @Controller but successful.

---

Below is an example of the main class.

@SpringBootApplication
public class MyApplication {
    public static void main(String[] args) {
        SpringApplication.run(MyApplication.class);
        new ItemFrame().setVisible(true);
    }
}

Answer 1

Spring will not manage instances created with new! Spring itself must create the class instance for the injections to work. The right one would be to inject the itemFrame object by Spring as well, but as the main method is Static we cannot inject with @Autowired. An alternative is to get the instance created by Spring through the Applicationcontext as follows:

@SpringBootApplication
public class MyApplication {

    public static void main(String[] args) {
    ApplicationContext context = new SpringApplicationBuilder(MyApplication.class)
    .headless(false).run(args);
    ItemFrame a = context.getBean(ItemFrame.class);
    a.setVisible(true);
    }
}

When you annotate a class with @Component, @Service , @Repository or @Controller Spring creates an instance of that class by calling your constructor without parameters or the constructor annotated with @Autowired if it exists. When creating it, it injects all its dependencies correctly and the instance is in your Applicationcontext. Classes created with new will not be managed by Spring unless you place them in the application context manually.

Also, to run with Spring Boot you must put the option . headless(false). And also the Itemframe class must be annotated with @Component in order to be injected.

@Component
public class ItemFrame extends JFrame{
    ...
}