Repository object not being Autowired in Service class

Question

I am having a Repository through which I'm getting data from Elasticsearch. It is working correctly when I send a GEt request. I need that data from Elasticsearch without sending a GET request for which I've written a Service and annotated that repository in Service class using @Autowired.
Repository

@Repository
public interface RecipeDtoRepository extends 
ElasticsearchRepository<RecipeDto, Integer> {}

Controller

@RestController
@RequestMapping("/repo")
public class RecipeRepoController {
@Autowired
public RecipeDtoRepository recipeDtoRepository;

@GetMapping("/all")
public String getRecipes() {
    List<RecipeDto> recipe_list = new ArrayList<>();
    recipeDtoRepository.findAll().forEach(recipe_list::add);
    return recipe_list.toString();
}

Service

@Service
@Component
public class ClusterService implements ApplicationContextAware {
  @Autowired
public RecipeDtoRepository recipeDtoRepository;
List<RecipeDto> recipe_list = new ArrayList<>();
   new ClusterService(). applicationContext.getBean(RecipeRepoController.class).recipeDtoRepository.findAll().forEach(recipe_list::add);
}
@Override
public void setApplicationContext(ApplicationContext 
applicationContext) throws BeansException {
    this.applicationContext = applicationContext;
}

Problem when calling the method in controller using GET request, it is working fine but when I call it using Service class, it is throwing NullPointerException which it shouldn't be according to my knowledge. I read an article where it was suggested to get the Bean in Service class which you can see I've done using ApplicationContext but it is throwing that exception. I've tried it without using ApplicationContext and it throws NullPointerException in that case too. I'm working over it for the last two days and unable to find a solution.

@Service
@Configurable
public class ClusterService {
@Autowired
public  RecipeDtoRepository recipeDtoRepository;

private  String getRecipes() {
    List<RecipeDto> recipe_list = new ArrayList<>();
    recipeDtoRepository.findAll().forEach(recipe_list::add);
    return recipe_list.toString();
}


public static void main(String[] a) {

    ClusterService clusterService = new ClusterService();
    clusterService.getRecipes();

}}

You appear to be using `new ClusterService()` which would create the `ClusterService` outside of Spring. — Ashley Frieze, Sep 17 '19 at 15:35
@AshleyFrieze what am I supposed to do. I've to call Repository in **ClusterService** class and fetch data in it — Jamshaid, Sep 17 '19 at 15:37
I presume you're trying to get your controller to use the service. So Autowire the service into the controller. Wherever you need a Spring Bean you need to get Spring to provide it to your calling code. You should not be using the application context directly, instead, you let Spring build all your beans and you express how they need each other. — Ashley Frieze, Sep 17 '19 at 15:38
@Jamshaid replace `new ClusterService(). applicationContext` with `context` and `@Autowired private ApplicationContext context;` — Pasupathi Rajamanickam, Sep 17 '19 at 15:39
` new ClusterService(). applicationContext.getBean ... ` this line in class context does not even compile. Please take time to post your example in a form that at least compiles. On top of that: you probably don't need ApplicationContextAware to inject a bean, can you show us your attempt with that approach? — Lesiak, Sep 17 '19 at 15:41
@PasupathiRajamanickam I'm in main() and need it there. As I've tried, we can't apply **Autowired** on static fields and by creating a new object, it'll again leave spring — Jamshaid, Sep 17 '19 at 15:43
@AshleyFrieze I've posted the controller in order to show how code is there and is in working form. I'm not calling Service in controller — Jamshaid, Sep 17 '19 at 15:44
Super confused, can you format your code add all the static stuff you're talking about? — Pasupathi Rajamanickam, Sep 17 '19 at 15:46
@Lesiak I didn't get your point. would you please elaborate it more. Thans — Jamshaid, Sep 17 '19 at 15:46
Possible duplicate of [Why is my Spring @Autowired field null?](https://stackoverflow.com/questions/19896870/why-is-my-spring-autowired-field-null) — daniu, Sep 17 '19 at 15:46
@PasupathiRajamanickam please have a look at the question again — Jamshaid, Sep 17 '19 at 16:09
@Jamshaid how you are binding the service in controller, also can you post the stacktrace? — triples13, Sep 17 '19 at 16:23
@Jamshaid i know you are trying to test but please don't do ClusterService clusterService = new ClusterService(); if you have used stereotype annotation — triples13, Sep 17 '19 at 16:25
@Jamshaid so you are trying to call the service using main method? — triples13, Sep 17 '19 at 16:27
Yeah/. You're right . I'm calling it using main. Please see the question again. Have a look at edit 1 — Jamshaid, Sep 17 '19 at 16:30
@Jamshaid Why do you have a main method in the middle of spring bean class? There is no such thing exist. You should have only one main that initialize SpringbootApplication. Spring wont work with main in middle of bean. — Pasupathi Rajamanickam, Sep 17 '19 at 16:30
You should autowire your service class in controller and call method inside service class that's how things works. If you would like to persist something in memory, you should consider using `@PostConstruct` and utilize the member list — Pasupathi Rajamanickam, Sep 17 '19 at 16:32
@PasupathiRajamanickam can you please provide a reference link for your 2nd last comment. Thanks — Jamshaid, Sep 17 '19 at 16:36

heyhooo · Answer 1 · 2019-09-17T15:56:17.317

1

Remove the contextAware and dont call the instance of repository from the controller since you have injected it yet just do this

public void addThings(){
this.recipeDtoRepository.findAll().forEach(recipe_list::add)
}

edited Sep 17 '19 at 15:56

answered Sep 17 '19 at 15:42

heyhooo

82
6

How am i supposed to do that? – Jamshaid Sep 17 '19 at 15:47
wait, just remove the new Cluster.... all line and create a method inside yopu put your behaviour like – heyhooo Sep 17 '19 at 15:54
as I'm accessing it in main() , it'll ask me to access it using an object which will obviously be created using new and that won't work again as we can't apply @Autowired on static fields – Jamshaid Sep 17 '19 at 15:54
dont use the controller to access the repository, you have injected it yet – heyhooo Sep 17 '19 at 15:54
Why do you access it from main? – heyhooo Sep 17 '19 at 15:57
can you give me all the context so i can see? – heyhooo Sep 17 '19 at 15:57
As I need to do it by directly running this class. It is performing a bit separate task from the original application – Jamshaid Sep 17 '19 at 15:59
so call the method from the class, but you don't need to access the instance of the repository defined in the controller, you have it – heyhooo Sep 17 '19 at 16:00
by all the context you mean repository class and content of the main method? – Jamshaid Sep 17 '19 at 16:01
please have a look at the quesion. I've just edited it – Jamshaid Sep 17 '19 at 16:05
also remove @ Component from your ClusterService as @ Service is an @ Component – heyhooo Sep 17 '19 at 16:05
Now having just @Service and same exception – Jamshaid Sep 17 '19 at 16:07
ok i understand in the main method you create an instance of the spring context ApplicationContext context = new AnnotationConfigApplicationContext(YourConfigurationClass.class); next you get the instance of clusterService by doing Clusterservice service = context.getBean(ClusterService.class); – heyhooo Sep 17 '19 at 16:09
public static void main(String[] args) { ApplicationContext context = new AnnotationConfigApplicationContext(YourConfigurationClass.class); Clusterservice service = context.getBean(ClusterService.class); clusterService.getRecipes(); } – heyhooo Sep 17 '19 at 16:10
which one is the configuration class? – Jamshaid Sep 17 '19 at 16:11
your configuration class, usually it's annotated with @Configuration – heyhooo Sep 17 '19 at 16:11
and remove @@Configurable from the ClusterService – heyhooo Sep 17 '19 at 16:11
I've a configuration class defined for elasticsearch configuration but it isn't accepting that – Jamshaid Sep 17 '19 at 16:14
No qualifying bean of type 'com.techno.homes.search.service.ClusterService' available – Jamshaid Sep 17 '19 at 16:15
did your configuration class scan the package of Clusterservice? – heyhooo Sep 17 '19 at 16:16
are you using spring boot? – heyhooo Sep 17 '19 at 16:17
yeah. I'm using spring boot – Jamshaid Sep 17 '19 at 16:19
ok so just remove the parameter of annotation...context and replace it by ApplicationContext conntext= new AnnotationConfigApplicationContext(); – heyhooo Sep 17 '19 at 16:20
Config class doesn't scan anything. It just has @ Configuration – Jamshaid Sep 17 '19 at 16:21
org.springframework.context.annotation.AnnotationConfigApplicationContext@5d47c63f has not been refreshed yet this error – Jamshaid Sep 17 '19 at 16:22
call context.refresh() before;it seems to scan the package of the Config class, is it in the same package as the clusterService? – heyhooo Sep 17 '19 at 16:23
context.refresh isn't available. – Jamshaid Sep 17 '19 at 16:25
It isn't in the same packge. – Jamshaid Sep 17 '19 at 16:25

score 1 · Answer 2 · answered Sep 17 '19 at 16:32

1

if you have annotated your class using stereotype annotation and you are trying to get bean in main class try this

     ApplicationContext context= 
           SpringApplication.run(Main.class,args);
                ClusterService clusterService=context.getBean(ClusterService.class);
clusterService.getRecipes();

answered Sep 17 '19 at 16:32

triples13

206
4
18

@Jamshaid please see https://stackoverflow.com/questions/52267478/should-i-never-use-new-keyword-on-a-spring-boot-project – triples13 Sep 17 '19 at 16:36

score 1 · Answer 3 · answered Sep 17 '19 at 16:42

1

Assuming that OP wants to persist a list and use it through out the lifecycle. Here is my recommendation

@Service
public class ClusterService {
    @Autowired
    public RecipeDtoRepository recipeDtoRepository;

    private List<RecipeDto> recipeList = null;

    @PostContruct
    public void setup() {
       recipeList = new ArrayList<>();
       recipeDtoRepository.findAll().forEach(recipeList::add);
    }

    public getReceipeList() {
      return recipeList;
    }

}

@RestController
@RequestMapping("/repo")
public class RecipeRepoController {
    @Autowired
    ClusterService clusterService

    @GetMapping("/all")
    public String getRecipes() {
        return clusterService.getReceipeList().toString();
    }
}

answered Sep 17 '19 at 16:42

Pasupathi Rajamanickam

1,982
1
24
48

I've this thing already in working format as I mentioned in my question. – Jamshaid Sep 17 '19 at 16:45
I was trying to access the data using the new main method, which you said isn't true. Can you please give me a reference link for that. – Jamshaid Sep 17 '19 at 16:46
It is impossible to use `public static void main` and make spring dependency work. It's like you want orange from apple tree :) – Pasupathi Rajamanickam Sep 17 '19 at 16:49
If you want something from spring but you don't need any controller, you should probably use spring-batch https://www.baeldung.com/introduction-to-spring-batch – Pasupathi Rajamanickam Sep 17 '19 at 16:50

Repository object not being Autowired in Service class

3 Answers3