[자바 ORM 표준 JPA] JPA 실전 예제 6 - 값 타입 매핑

[자바 ORM 표준 JPA] JPA 실전 예제 6 - 값 타입 매핑

실전 예제 6 - 값 타입 매핑

값 타입 추가#

  • city, street, zipcode 는 Address 값 타입으로 변경

값 타입 추가 순서#

  1. 값 타입 클래스 추가 - Address.java
  1. @Embeddable 어노테이션 추가
  1. 불변 객체로 생성 3.1. 필드(맴버 변수) 추가 3.2. getter 추가 3.3. setter private로 생성 또는 생성 X
  • 값 타입은 공유해서 사용시 변경이 되면 같이 사용하는 값 모두 변경되므로 주의
  • 값 타입은 변경하지 말고 객체를 새로 생성해서 갈아껴야함. 3.4. .equals()와 hashcode() 오버라이딩
  • == 비교에서 값 전체 비교로 변경
  1. 값 타입을 사용(Embedded)할 엔티티에 생성한 값 타입 추가

contact

Address.java - value type

package jpabasic.jpashop.domain;

import javax.persistence.Embeddable;

@Embeddable
public class Address {
    
    @Column(length = 10)
    private String cicy;
     
    @Column(length = 30)
    private String street;

    @Column(length = 5)    
    private String zipcode;
	
    // Address 를 사용하는 곳에서 같이 사용할 수 있는 메소드
    public String fullAddress(){
        return getCicy() +" "+ getStreet() +" ("+getZipcode()+")";
    }
    
    public String getCicy() {
        return cicy;
    }

    private void setCicy(String cicy) {
        this.cicy = cicy;
    }

    public String getStreet() {
        return street;
    }

    private void setStreet(String street) {
        this.street = street;
    }

    public String getZipcode() {
        return zipcode;
    }

    private void setZipcode(String zipcode) {
        this.zipcode = zipcode;
    }
}

contact

code generation 할때, 아래 옵션을 선택하면, 필드에 직접 접근하는게 아니라 클래스의 Getter 메서드를 사용.

프록시일 경우 필드에 직접 접근하면 계산이 안되기 때문에 getter 메소드를 이용해서 equals()와 hashcode()를 오버라이딩해야함.

수정된 소스#

Member.java

package jpabasic.jpashop.domain;

import javax.persistence.*;
import java.util.ArrayList;
import java.util.List;

@Entity
public class Member extends BaseEntity{

    public Member(){}

    @Id @GeneratedValue
    @Column(name="MEMBER_ID")
    private Long id;
    private String name;
	
	// ***
    @Embedded // Address 에서 @Embeddable 추가시 생략가능
    private Address address;

    @OneToMany(mappedBy = "member")
    private List<Order> orders = new ArrayList<>(); //관례상 초기 값을 두어 NullPointer Exception을 방지

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public List<Order> getOrders() {
        return orders;
    }

    public void setOrders(List<Order> orders) {
        this.orders = orders;
    }

    public Address getAddress() {
        return address;
    }

    public void setAddress(Address address) {
        this.address = address;
    }
}

Delivery.java

package jpabasic.jpashop.domain;

import javax.persistence.*;

@Entity
public class Delivery extends BaseEntity{

    @Id @GeneratedValue
    @Column(name = "DELIVERY_ID")
    private Long id;

    @Embedded
    private Address address;

    @Enumerated(EnumType.STRING)
    private DeliveryStatus status;


    @OneToOne(mappedBy = "delivery" , fetch = FetchType.LAZY)
    private Order order;

    public void setId(Long id) {
        this.id = id;
    }

    public Long getId() {
        return id;
    }

    public DeliveryStatus getStatus() {
        return status;
    }

    public void setStatus(DeliveryStatus status) {
        this.status = status;
    }

    public Order getOrder() {
        return order;
    }

    public void setOrder(Order order) {
        this.order = order;
    }

    public Address getAddress() {
        return address;
    }

    public void setAddress(Address address) {
        this.address = address;
    }
}

이전과 동일 소스#

Album.java

package jpabasic.jpashop.domain;

import javax.persistence.DiscriminatorValue;
import javax.persistence.Entity;

@Entity
@DiscriminatorValue("A")
public class Album extends Item{
    private String artist;
    private String etc;

    public String getArtist() {
        return artist;
    }

    public void setArtist(String artist) {
        this.artist = artist;
    }

    public String getEtc() {
        return etc;
    }

    public void setEtc(String etc) {
        this.etc = etc;
    }
}

BaseEntity.java

package jpabasic.jpashop.domain;


import javax.persistence.Column;
import javax.persistence.MappedSuperclass;
import java.time.LocalDateTime;

@MappedSuperclass
public abstract class BaseEntity {
    @Column(name = "REG_ID")
    private String createBy;

    @Column(name = "REG_DT")
    private LocalDateTime createDate;

    @Column(name = "MOD_ID")
    private String LastModifiedBy;

    @Column(name = "MOD_DT")
    private LocalDateTime LastModifiedDate;

    public String getCreateBy() {
        return createBy;
    }

    public void setCreateBy(String createBy) {
        this.createBy = createBy;
    }

    public LocalDateTime getCreateDate() {
        return createDate;
    }

    public void setCreateDate(LocalDateTime createDate) {
        this.createDate = createDate;
    }

    public String getLastModifiedBy() {
        return LastModifiedBy;
    }

    public void setLastModifiedBy(String lastModifiedBy) {
        LastModifiedBy = lastModifiedBy;
    }

    public LocalDateTime getLastModifiedDate() {
        return LastModifiedDate;
    }

    public void setLastModifiedDate(LocalDateTime lastModifiedDate) {
        LastModifiedDate = lastModifiedDate;
    }
}

Book.java

package jpabasic.jpashop.domain;

import javax.persistence.DiscriminatorValue;
import javax.persistence.Entity;

@Entity
@DiscriminatorValue("B")
public class Book extends Item{
    private String author;
    private String isbn;

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public String getIsbn() {
        return isbn;
    }

    public void setIsbn(String isbn) {
        this.isbn = isbn;
    }
}

Category.java

package jpabasic.jpashop.domain;

import javax.persistence.*;
import java.util.ArrayList;
import java.util.List;

@Entity
public class Category extends BaseEntity{

    @Id @GeneratedValue
    @Column(name = "CATEGORY_ID")
    private Long id;

    private String name;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "parent_id")
    private Category parent; // 상위 카테고리

    @OneToMany(mappedBy = "parent")
    private List<Category> child = new ArrayList<>();   // 자식 카테고리

    @ManyToMany
    @JoinTable(name = "CATEGORY_ITEM",
                joinColumns = @JoinColumn(name = "CATEGORY_ID"),
                inverseJoinColumns = @JoinColumn(name ="ITEM_ID")
    )
    private List<Item> items = new ArrayList<>();

    public void setId(Long id) {
        this.id = id;
    }

    public Long getId() {
        return id;
    }
}

DeliveryStatus.java

package jpabasic.jpashop.domain;

public enum DeliveryStatus {
    ORDER, CANCEL
}

Item.java

package jpabasic.jpashop.domain;

import javax.persistence.*;
import java.util.ArrayList;
import java.util.List;

@Entity
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn
public abstract class Item extends BaseEntity{
    public Item(){
    }

    public Item(String name, int price, int stockQuantity) {
        this.name = name;
        this.price = price;
        this.stockQuantity = stockQuantity;
    }

    @Id @GeneratedValue
    @Column(name="ITEM_ID")
    private Long id;
    private String name;
    private int price;
    private int stockQuantity;

    @ManyToMany(mappedBy = "items")
    private List<Category> categories = new ArrayList<>();

    public Long getId() {
        return id;
    }


    public void setId(Long id) {
        this.id = id;
    }


    public String getName() {
        return name;
    }

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

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    public int getStockQuantity() {
        return stockQuantity;
    }

    public void setStockQuantity(int stockQuantity) {
        this.stockQuantity = stockQuantity;
    }
}

Movie.java

package jpabasic.jpashop.domain;

import javax.persistence.DiscriminatorValue;
import javax.persistence.Entity;

@Entity
@DiscriminatorValue("M")
public class Movie extends Item{
    private String director;
    private String actor;

    public String getDirector() {
        return director;
    }

    public void setDirector(String director) {
        this.director = director;
    }

    public String getActor() {
        return actor;
    }

    public void setActor(String actor) {
        this.actor = actor;
    }
}

Order.java

package jpabasic.jpashop.domain;

import javax.persistence.*;
import jpabasic.jpashop.domain.Member;
import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

@Entity
@Table(name = "ORDERS") // DB에 따라 ORDER가 예약어일 경우가 있어 ORDERS
public class Order extends BaseEntity{

    public Order(){}

    @Id
    @GeneratedValue
    @Column(name="ORDER_ID")
    private Long id;

    private LocalDateTime orderDate;

    @Enumerated(EnumType.STRING)
    private OrderStatus status;

    @ManyToOne(fetch = FetchType.LAZY)
    private Member member;

    @OneToMany(mappedBy = "order", cascade = CascadeType.ALL)
    private List<OrderItem> orderItems = new ArrayList<>(); //관례상 초기 값을 두어 NullPointer Exception을 방지

    @OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinColumn(name = "DELIVERY_ID")
    private Delivery delivery;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public LocalDateTime getOrderDate() {
        return orderDate;
    }

    public void setOrderDate(LocalDateTime orderDate) {
        this.orderDate = orderDate;
    }

    public OrderStatus getStatus() {
        return status;
    }

    public void setStatus(OrderStatus status) {
        this.status = status;
    }

    public Member getMember() {
        return member;
    }

    public void setMember(Member member) {
        this.member = member;
    }

    public List<OrderItem> getOrderItems() {
        return orderItems;
    }

    public void setOrderItems(List<OrderItem> orderItems) {
        this.orderItems = orderItems;
    }

    public void addOrderItem(OrderItem orderItem) {
        this.orderItems.add(orderItem);
        orderItem.setOrder(this);
    }

    public void addMember(Member member) {
        this.member = member;
        member.getOrders().add(this);
    }
}

OrderItem.java

package jpabasic.jpashop.domain;

import javax.persistence.*;
import java.util.List;

@Entity
public class OrderItem extends BaseEntity{
    public OrderItem(){
    }

    @Id @GeneratedValue
    @Column(name = "OFDER_ITEM_ID")
    private Long id;

    private int orderPrice;

    private int count;

    @ManyToOne(fetch = FetchType.LAZY)
    private Order order;

    @ManyToOne(fetch = FetchType.LAZY)
    private Item item;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public int getOrderPrice() {
        return orderPrice;
    }

    public void setOrderPrice(int orderPrice) {
        this.orderPrice = orderPrice;
    }

    public int getCount() {
        return count;
    }

    public void setCount(int count) {
        this.count = count;
    }

    public Order getOrder() {
        return order;
    }

    public void setOrder(Order order) {
        this.order = order;
    }

    public Item getItem() {
        return item;
    }

    public void setItem(Item item) {
        this.item = item;
    }
}

OrderStatus.java

package jpabasic.jpashop.domain;

public enum OrderStatus {
    ORDER, CANCEL
}

JpaMain.java

package jpabasic.jpashop;

import jpabasic.jpashop.domain.*;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.Persistence;

public class JpaMain {
    public static void main(String[] args) {
        EntityManagerFactory emf = Persistence.createEntityManagerFactory("jpashop");
        EntityManager em = emf.createEntityManager();
        EntityTransaction tx = em.getTransaction();

        tx.begin();

        try{
            Book book = new Book();
            book.setName("JPA");
            book.setAuthor("김영한");
            em.persist(book);

            tx.commit();

        }catch (Exception e){
            e.printStackTrace();
            tx.rollback();
        }finally {
            em.close();
        }
        emf.close();

    }
}

JpaMain.java - 애플리케이션 재시작

console

Hibernate: 
    
    create table Delivery (
       DELIVERY_ID bigint not null,
        MOD_ID varchar(255),
        MOD_DT timestamp,
        REG_ID varchar(255),
        REG_DT timestamp,
        cicy varchar(10),
        street varchar(30),
        zipcode varchar(5),
        status varchar(255),
        primary key (DELIVERY_ID)
    )
Hibernate: 
    
    create table Member (
       MEMBER_ID bigint not null,
        MOD_ID varchar(255),
        MOD_DT timestamp,
        REG_ID varchar(255),
        REG_DT timestamp,
        cicy varchar(10),
        street varchar(30),
        zipcode varchar(5),
        name varchar(255),
        primary key (MEMBER_ID)
    )

값 타입의 장점#

  1. 공통 메소드 같이 사용
  2. 컬럼의 길이 등 옵션 동일 적용
  3. 제약조건 동일 적용

참고- 자바 ORM 표준 JPA - 김영한#

[자바 ORM 표준 JPA] JPA 실전 예제 6 - 값 타입 매핑