Rest template giving null body and status 302

Question

I am trying to consume a rest call in my mvc controller, however every time I do it returns a null body with http status as 302.Also I am using spring boot with spring security to get https.

I've followed code samples from here: http://websystique.com/springmvc/spring-mvc-4-restful-web-services-crud-example-resttemplate/ and Get list of JSON objects with Spring RestTemplate however none of these work

Can someone please point me in the right direction

Thank you,

REST

@RequestMapping(value = "/api/*")
@RestController
public class PostApiController {

static final Logger logger = LogManager.getLogger(PostApiController.class.getName());
private final PostService postService;


@Inject
public PostApiController(final PostService postService) {
    this.postService = postService;
}

  //-------------------Retrieve All Posts--------------------------------------------------------

@RequestMapping(value = "post", method = RequestMethod.GET)
public ResponseEntity<List<Post>> getAllPosts() {
    List<Post> posts = postService.findAllPosts();
    if(posts.isEmpty()){
        return new ResponseEntity<List<Post>>(HttpStatus.NO_CONTENT);//You many decide to return HttpStatus.NOT_FOUND
    }
    return new ResponseEntity<List<Post>>(posts, HttpStatus.OK);
  }

}

Controller

@Controller
public class PostController {

static final Logger logger = LogManager.getLogger(PostController.class.getName());

 public static final String REST_SERVICE_URI =  "http://localhost:8080/api"; //"http://localhost:8080/api";


private final PostService postService;

@Inject
public PostController(final PostService postService) {
    this.postService = postService;
}



@SuppressWarnings("unchecked")
@RequestMapping(value = "/getAll")
// public String create(@Valid Post post, BindingResult bindingResult, Model
// model) {
public ModelAndView getAll() {
    // if (bindingResult.hasErrors()) {
    // return "mvchome";
    // }


     RestTemplate restTemplate = new RestTemplate();

     ResponseEntity<List<Post>> responseEntity = restTemplate.exchange(REST_SERVICE_URI+"/post",HttpMethod.GET, null, new ParameterizedTypeReference<List<Post>>() {});
    // ResponseEntity<Post[]> responseEntity = restTemplate.getForEntity(REST_SERVICE_URI+"/post", Post[].class);
     List<Post> postsMap = responseEntity.getBody();
     MediaType contentType = responseEntity.getHeaders().getContentType();
     HttpStatus statusCode = responseEntity.getStatusCode();

       // List<LinkedHashMap<String, Object>> postsMap = restTemplate.getForObject(REST_SERVICE_URI+"/post", List.class);
      //  String s= REST_SERVICE_URI+"/post";
       // logger.info(s);
        if(postsMap!=null){
            for(Post map : postsMap){
                logger.info("User : id="+map.getUid());
            }
        }else{
            logger.info("No user exist----------");
        }



    //List<Post> postList = postService.findAllPosts();
    ModelAndView mav = new ModelAndView("mvchome");
    mav.addObject("postsList", postsMap);
    Post newpost = new Post();

    mav.addObject("post", newpost);
    return mav;

    }
 }

***** to fix my issue I modified my code to just do a redirect on select url paths instead of "/*"

 @Bean
  public EmbeddedServletContainerFactory servletContainer() {
    TomcatEmbeddedServletContainerFactory tomcat =
      new TomcatEmbeddedServletContainerFactory() {

        @Override
        protected void postProcessContext(Context context) {
          SecurityConstraint securityConstraint = new SecurityConstraint();
          securityConstraint.setUserConstraint("CONFIDENTIAL");
          SecurityCollection collection = new SecurityCollection();
          //used to be just collection.addPattern("/*"); now I changed it to specify which path I want it to redirect
          collection.addPattern("/mvchome/*");
          collection.addPattern("/home/*");
          securityConstraint.addCollection(collection);
          context.addConstraint(securityConstraint);
        }
      };
    tomcat.addAdditionalTomcatConnectors(createHttpConnector());
    return tomcat;
  }

Answer 1

The http status 302 is usually caused by wrong url setting.

First, make sure that public ResponseEntity<List<Post>> getAllPosts() {} method is called (just print List<Post> result inside it).

If it's called properly and you can get the return value inside public ModelAndView getAll() {}.

The problem should be the directing setting of the public ModelAndView getAll() {} method.

Check if you make something wrong in your web.xml or spring configuration. Pay attention to the configuration which redirects to views and the url mapping of your dispatcher servlet.

---

If public ResponseEntity<List<Post>> getAllPosts() {} is called but you can't get the return value, then it should be the issues of directing setting of the public ResponseEntity<List<Post>> getAllPosts() {} method.

Check your spring configuration and web.xml for that. The possible cause usually will be the misuse of wildcard in the configuration and web.xml, or just unnoticed wrong mapping.