How to read a file and assign it to an ArrayList in spring?

Question

Consider the following classes:

public class Store {
    private final ArrayList<String> store;
    public ArrayList<String> getStore() {
        return store;
    }
    public Store(ArrayList<String> store){
        this.store = store;
    }
}

I have a text file called input.txt
I have a normal controller which is annotated with @RestController as follows:

@RestController
@RequestMapping(value="/test")
public class Controller {

    .
    .
    .

}

I need to do the following operations:

1. Read input.txt by using Files.readAllLines(path,cs) (from JDK 1.7)
2. Set the returned value(List<String>) to Store.store
3. I wanna use Spring annotations all the way (I'm writing a spring-boot application)
4. I need Store to be a Singleton bean.
5. The store needs to be initialized during the bootstrapping of my application.

This question might be too vague, but I have absolutely no idea about how to make it more specific.

P.S.
I'm a newbie to Spring.

Answer 1

It seems like using Constructor Injection would be ideal.

public class Store {
    private final List<String> storeList;

    @Autowired
    public Store(@Value("${store.file.path}") String storeFilePath) throws IOException {
            File file = new File(storeFilePath);
            storeList = Files.readAllLines(file.toPath());
    }
}

you will want to add the store.file.path property to your properties file that is read in by your spring context. You will also want to add a bean definition for Store

<bean id="Store" class="com.test.Store" />

Then your Rest Controller can look something like this:

@RestController
@RequestMapping(value="/store")
public class StoreRestController {

    @Autowired
    Store store;

    @RequestMapping(value="/get", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
    public ResponseEntity<Store> getStore(HttpServletRequest request) {
        ResponseEntity<Store> response = new ResponseEntity<Store>(store, HttpStatus.OK);
        return response;
    }
}

There's a couple different ways to write your injection & controller so do some research and use the method that best suites your needs.