Annotation - @NonNull

@NonNull
해당 필드가 null 값을 가질 수 없도록 설정

메소드에서 @NonNull 어노테이션을 사용하여 
매개변수가 null이면 예외를 발생시킬 수 있다.

import lombok.NonNull;

public class Person {
    private String name;
    @NonNull
    private int age;

    public Person(String name, @NonNull int age) {
        this.name = name;
        this.age = age;
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setAge(@NonNull int age) {
        this.age = age;
    }
}

 

 

 

https://standout.tistory.com/28

null이란?