spring boot - Return empty string instead of null in SpringBoot Web response

Question

I am trying to get an empty string instead of null in the response from a HTTP rest controller in a Spring Boot Web project.

The return code is as follows: an ArrayNode class wrapped into ResponseEntity

return new ResponseEntity<>(result, HttpStatus.OK);

The image below shows that it is a NullNode in the response and the second image shows the response in Postman. I would like the contactNumber field to be empty string instead of null.

question from:https://stackoverflow.com/questions/66060765/return-empty-string-instead-of-null-in-springboot-web-response

Answer 1

You must define your own CustomNullStringSerializerProvider and call him in your ObjectMapper

https://digitaljoel.nerd-herders.com/2015/03/18/how-to-make-jackson-serialize-null-strings-differently-than-null-objects/

Josselin