How to create a link pointing to a Spring controller action that returns void

Question

I am using spring mvc, hateoas. I have a controller action that looks like

@RequestMapping(value = "/images/{userId}/{publicUrl}/{fileName:.+}", method = RequestMethod.GET) public void image(@PathVariable Integer userId, @PathVariable String publicUrl, @PathVariable String fileName, HttpServletRequest request, HttpServletResponse response) throws Exception { try(HellodoxAws aws = haws;){ ..... ..... response.setContentType(image.getObjectMetadata().getContentType()); response.setHeader("ETag",image.getObjectMetadata().getETag()); response.setHeader("Cache-Control",image.getObjectMetadata().getCacheControl()); response.setHeader("Last-Modified",image.getObjectMetadata().getLastModified().toString()); IOUtils.copy(image.getObjectContent(), response.getOutputStream()); }catch (Exception e) { if(e instanceof AmazonS3Exception){ int statusCode = ((AmazonS3Exception) e).getStatusCode(); //System.out.println("Status Code : "+statusCode); response.setContentType("image/jpeg"); if(statusCode==HttpStatus.NOT_MODIFIED.value()){ response.setHeader("ETag",((AmazonS3Exception) e).getAdditionalDetails().get("ETag")); response.setHeader("Cache-Control",((AmazonS3Exception) e).getAdditionalDetails().get("Cache-Control")); response.setHeader("Last-Modified",((AmazonS3Exception) e).getAdditionalDetails().get("Last-Modified")); } response.setStatus(statusCode); } } } 

This action works fine.

Now I want to publish a url to access the image of each profile. JSON format is something like this

 { "profileId" : 342308, "userId" : 342308, "firstname" : "Henry", "lastname" : "Seol", "title" : "Mr.", "largeImageUrl" : "https://<host>/image/<id>/<publicUrl>/<filename1.jpg>", "thumbImageUrl" : "https://<host>/image/<id>/<publicUrl>/<filename2.jpg>" } 

I want to add this link instead of the value for "largeImageUrl" and "thumbImageUrl".

If I use the linkTo function in hate methods, it says that the corresponding method should not return void.

How to create such a dynamic link and add it to the resource?

Answer 1

you can use

 public static ControllerLinkBuilder linkTo(Class<?> controller, Method method, Object... parameters) { 

So it should be something like

 Link link = linkTo( ImageController.class, ImageController.class .getMethod("image", Integer.class, String.class, String.class, HttpServletRequest.class, HttpServletResponse.class), 1, "url", "file" ).withRel("image"); 

Note: There is a shorter method.

 public static ControllerLinkBuilder linkTo(Method method, Object... parameters) { 

but it has an error, so it does not work