spring CRUD DELETE action that return viewmodel or empty body

Question

I want to write a DELETE action that return a no content body if no id error exist. If id not exist I want to redirect to the coresponding GET view.

Controller code:

@RequestMapping(value = "/todo/delete/{id}", method = RequestMethod.GET)
public String getDeleteTodo(Model model, @PathVariable("id") String id)
{
    Optional<Todo> todo = todoRepository.findById(Long.decode(id));

    if (todo.isEmpty()) {
        model.addAttribute("msginfo", "ctl-todo.delete.msginfo.id-not-exist");
        model.addAttribute("requestedId", id);
    }
    else {
        model.addAttribute("todo", todo.get());
    }

    return "v-todo-delete";
}

@RequestMapping(value = "/todo/delete/{id}", method = RequestMethod.DELETE)
public String deleteTodo(@PathVariable String id, RedirectAttributes redirAttrs)
{
    boolean exists = todoRepository.existsById(Long.decode(id));

    if (exists) {
        todoRepository.deleteById(Long.decode(id));
        return ""; //here I want to return a no-content body response
    }
    else {
        redirAttrs.addFlashAttribute("msginfo", "ctl-todo.delete.msginfo.id-not-exist");
        redirAttrs.addFlashAttribute("requestedId", id);

        return "redirect:/todo/delete" + id;
    }
}

More informations about the view:

The GET view is juste a view that display the todo entity corresponding to the id. The deletion is make with a button using ajax to call the DELETE method. Then response is return as 204 with no content into the body, i redirect the user with javascript to the main page... If an id not exist in the DELETE method, I want to redirect to the GET method to show an error message.

If someone have an idea to do this. Thanks in advance.

you should follow REST principles. delete with 204 with no content is correct incase id is present . if id isnot present throw exception 404 .handle 404 on UI — Mandar Dharurkar, Jan 12 '20 at 13:04
Have you an example to do this ? Or a like to a github project that do it ? It's a little bit complex for me for the moment. — BeRoots, Jan 12 '20 at 13:26
I have added the answer that will redirect to index directly with no content response . hope that might help ! — Mandar Dharurkar, Jan 12 '20 at 14:17

score 1 · Answer 1 · answered Jan 12 '20 at 13:55

1

Try using return type as ResponseEntity with whatever response body along with a response status. Please refer below code changes:

@RequestMapping(value = "/todo/delete/{id}", method = RequestMethod.DELETE)
public ResponseEntity deleteTodo(@PathVariable String id, RedirectAttributes redirAttrs)
{
   boolean exists = todoRepository.existsById(Long.decode(id));

   if (exists) {
       todoRepository.deleteById(Long.decode(id));
       return new ResponseEntity(HttpStatus.NO_CONTENT); //This will return No Content status
   }
   else {
       redirAttrs.addFlashAttribute("msginfo", "ctl-todo.delete.msginfo.id-not-exist");
       redirAttrs.addFlashAttribute("requestedId", id);

       return new ResponseEntity( "redirect:/todo/delete" + id, HttpStatus.OK);
   }
}

answered Jan 12 '20 at 13:55

Jeethesh Kotian

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using responeEnity will remove the model . – Mandar Dharurkar Jan 12 '20 at 14:09
Yes, but as in it gives you more control on the Response status you use and also you can have whatever response body you need without having to specify the return type beforehand. – Jeethesh Kotian Jan 12 '20 at 14:13
1

agree ! but in this particular case response is viewmodel (jsp) page. hence ResponseEntity would not suffice . – Mandar Dharurkar Jan 12 '20 at 14:15
I have post the final answer. I will mark as anwser that solve the problem in 2 days... – BeRoots Jan 12 '20 at 14:47

BeRoots · Accepted Answer · 2020-01-12T15:00:58.807

Final anwser for me:

@RequestMapping(value = "/todo/delete/{id}", method = RequestMethod.DELETE)
public ResponseEntity<?> deleteTodo(@PathVariable String id, RedirectAttributes redirAttrs)
{
   boolean exists = todoRepository.existsById(Long.decode(id));

   if (exists) {
       todoRepository.deleteById(Long.decode(id));
       return new ResponseEntity<>(HttpStatus.NO_CONTENT);
   }
   else {
       redirAttrs.addFlashAttribute("msginfo", "ctl-todo.delete.msginfo.id-not-exist");
       redirAttrs.addFlashAttribute("requestedId", id);
       /* I use CONFLICT here to explain that the entity was possibly deleted
          by another user between the moment the user give the view containing
          the DELETE ajax link and the moment he click on it. */
       return new ResponseEntity<String>( "redirect:/todo/delete" + id, HttpStatus.CONFLICT);
   }
}

Thank you Mandar Dharurkar & Jeethesh Kotian for your help ;)

spring CRUD DELETE action that return viewmodel or empty body

2 Answers2