Spring @RequestHeader defaultValue 用于不需要的标头参数

Question

I am trying to add a default value to an optional header parameter for when it is not present. However, when the parameter is not included, I noticed that it is not being populated with the default value:

public Mono<User> getUser(
  @RequestHeader(value = "accept", defaultValue = "abc") String acceptHeader,
  ...
)

When I am debugging the code, acceptHeader is " / " when no the param is not specified. I looked online and could not find any reason as to why this is happening. Not sure if it makes a difference, but I am making the call with Postman. Does anyone have any idea why this is happening? I could implement code to handle this logic inside getUser but I would like to ideally use annotations.

Answer 1

/ is a default value so is not empty and defaultValue = "abc" doesn't work. If you want to do something when nothing was put into accept value use this instead it defaultValue = "abc" :

if (acceptHeader.eqals("/") {
    ... do something 
}