[json] How to post object and List using postman

//backend.

@PostMapping("/")
public List<A> addList(@RequestBody A aObject){
//......ur code
}

class A{
int num;
String name;
List<B> bList;
//getters and setters and default constructor
}
class B{
int d;
//defalut Constructor & gettes&setters
}

// postman

{
"num":value,
"name":value,
"bList":[{
"key":"value",
"key":"value",.....
}]
}
  1. the error is for list there is no default constructor .so we can keep our list of object as a property of another class and pass the list of objects through the postman as the parameter of the another class.