How to create Exception with HttpStatus and send it using Resource of Spring-Hateoas? - spring-boot

Question

I am using Spring-Boot 1.2.7 for developing Spring-Hateoas application with Spring-Data-JPA.
I have developed controller class with methods which returns Resource.
I want to create Exception with HttpStatus and use it in controller class for GET, POST, PUT and DELETE. Please assist me, I am new to this.
Controller Class - ArticleController
#RestController
#RequestMapping(value = "/api/articles")
public class ArticleController {
#Autowired
private ArticleService articleService;
#Autowired
private ArticleRepository articleRepository;
#Autowired
private ArticleResourceAssembler articleResourceAssembler;
/*#RequestMapping(method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
public Collection<Resource<Article>> getArticles() {
Collection<Article> articles = articleService.findAll();
List<Resource<Article>> resources = new ArrayList<Resource<Article>>();
for (Article article : articles) {
resources.add(getArticleResource(article));
}
return resources;
}*/
#RequestMapping(method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
public PagedResources<Article> getArticles(Pageable pageable, PagedResourcesAssembler assembler) {
Page<Article> articles = articleService.findAll(pageable);
return assembler.toResource(articles, articleResourceAssembler);
}
#RequestMapping(value = "/{article_id}", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
public Resource<Article> getArticle(#PathVariable(value = "article_id") long article_id) {
Article article = articleService.findOne(article_id);
if (article == null) {
ResponseEntity.status(HttpStatus.NOT_FOUND);
}
return getArticleResource(article);
}
// Insert Article
#RequestMapping(method = RequestMethod.POST, consumes = MediaType.APPLICATION_JSON_VALUE,
produces = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<Article> createArtilce(#RequestBody Article article) {
article.setCreated(new Date());
Article savedArticle = articleService.create(article);
article.add(linkTo(methodOn(ArticleController.class).getArticle(savedArticle.getArticle_id()))
.withSelfRel());
// I want to return here HttpStatus.NOT_FOUND
}
private Resource<Article> getArticleResource(Article article) {
Resource<Article> resource = new Resource<Article>(article);
// Link to Article
resource.add(linkTo(methodOn(ArticleController.class).getArticle(article.getArticle_id())).withSelfRel());
return resource;
}
}

Answer 1

You need to implement a class for the exception (that is extends from RuntimeException) and annotated with #ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR) or another Status code, and where you want throw that status, you need throw your CustomException.
For Exceptions you didn't write, can use a exception handler method inside your controller like this:
#ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
#ExceptionHandler({ExternalException.class})
public void metodoCuandoExcepcionEsLanzada(){
//logging and processing
}