Scaffolding code

• 연관을 맺기 위해 필요한 필드와 메소드.

1:다 관계

• 다수를 가질 경우, Hibernate requires interfaces for collection-typed attributes

• 양방향일 경우, 해당 타입의 속성이 필요함.

• 연결하기: 두 가지 행위가 필요함.

• Hibernate doesn't manage persistent associations. If you
  want to manipulate an association, you must write exactly the same code
  you would write without Hibernate.

• Convenient Method 도입하기:

public void addChildCategory(Category childCategory) {
    if (childCategory == null)
        throw new IllegalArgumentException("Null child category!");
    if (childCategory.getParentCategory() != null)
        childCategory.getParentCategory().getChildCategories().remove(childCategory);
    childCategory.setParentCategory(this);
    childCategories.add(childCategory);
}

• • reduces the lines of code

• • enforces the cardinality of the association

다:다 관계

• both sides are implemented with collection-valued attributes.

• Convenient Method

public void addCategory(Category category) {
    if (category == null)
        throw new IllegalArgumentException("Null category");
    category.getItems().add(this);
    categories.add(category);
}

• You can also add logic to your accessor methods.

참조 : Java Persistence With Hibernate