java - spring mvc receives an object. How to set different properties of the object?

Question

@RequestMapping(value = "/listByUserId")
public PageInfo<Product> listByUserId(User user) {
    
}

What I am receiving is a User object, in which the User attribute id, I want to set an initial value for it, that is, there is an initial value when the id parameter is not sent. I use @RequestParam to specify the id attribute defalutValue, but it does not work. Is there any way to achieve this? It is best not to change to the User class

Answer 1

This is what I wrote:

@RequestMapping(value="/student/{st_no}",method= RequestMethod.GET)
public Student info(@PathVariable Integer st_no){
}