How does JSON maps to List<> even after Type Erasure in Java

I was working with JSONs to send a list of objects to a controller in Spring. My controller method is this:

@PostMapping("/fun")
public String fun(List<User> users){
    for(User user : users){
       System.out.println(user);
  }
  return "success";
}

And this is my User class:

public class User{
    String name;
    String password;
    int empID;

    // getter and setters
}

This is the JSON which I am sending:

[
   {
      "name":"some-name",
      "password":"password",
      "empID":2
   }
]

My question is, how does JSON knows that this is List of User, because Java type erasure makes it impossible to know which kind of object does a List contains. So even without knowing the object how is JSON is able to map itself to User class.

Edited

What I actually want to do is this:

I have a class PayloadTester, which like this

public class PayloadTester{
   public void test(List<String> list){
       // logic
   }
}

From my main method I am using reflection apis to get test(List<String> list) method and from this method its parameters like this,

Method method = tester.getClass().getMethod("test", List.class);
Parameter[] params = method.getParameters();
// extracting param from this Parameter array.

I want to use this param which is List<String> and create a function/class get output as java.lang.String. Because Spring also does something like this where we only pass parameter and payload is mapped to them. How can I achieve that.