В этом учебном пособии будет повторно использована вся инфраструктура предыдущего ” Пример гибернации один к одному – сопоставление XML ” учебника, улучшите его для поддержки аннотации Hibernate/JPA.
Структура проекта
См. окончательную структуру проекта этого руководства.
1. ” Отношение таблицы “один к одному”
Еще раз просмотрите предыдущее отношение таблицы “один к одному”.
2. Класс модели гибернации
Создайте два класса моделей – Stock.java и StockDetail.java , и поместите код аннотации внутрь.
Файл: Stock.java
package com.mkyong.stock;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import static javax.persistence.GenerationType.IDENTITY;
import javax.persistence.Id;
import javax.persistence.OneToOne;
import javax.persistence.Table;
import javax.persistence.UniqueConstraint;
@Entity
@Table(name = "stock", catalog = "mkyongdb", uniqueConstraints = {
@UniqueConstraint(columnNames = "STOCK_NAME"),
@UniqueConstraint(columnNames = "STOCK_CODE") })
public class Stock implements java.io.Serializable {
private Integer stockId;
private String stockCode;
private String stockName;
private StockDetail stockDetail;
public Stock() {
}
public Stock(String stockCode, String stockName) {
this.stockCode = stockCode;
this.stockName = stockName;
}
public Stock(String stockCode, String stockName, StockDetail stockDetail) {
this.stockCode = stockCode;
this.stockName = stockName;
this.stockDetail = stockDetail;
}
@Id
@GeneratedValue(strategy = IDENTITY)
@Column(name = "STOCK_ID", unique = true, nullable = false)
public Integer getStockId() {
return this.stockId;
}
public void setStockId(Integer stockId) {
this.stockId = stockId;
}
@Column(name = "STOCK_CODE", unique = true, nullable = false, length = 10)
public String getStockCode() {
return this.stockCode;
}
public void setStockCode(String stockCode) {
this.stockCode = stockCode;
}
@Column(name = "STOCK_NAME", unique = true, nullable = false, length = 20)
public String getStockName() {
return this.stockName;
}
public void setStockName(String stockName) {
this.stockName = stockName;
}
@OneToOne(fetch = FetchType.LAZY, mappedBy = "stock", cascade = CascadeType.ALL)
public StockDetail getStockDetail() {
return this.stockDetail;
}
public void setStockDetail(StockDetail stockDetail) {
this.stockDetail = stockDetail;
}
}
Файл: StockDetail.java
package com.mkyong.stock;
import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.OneToOne;
import javax.persistence.PrimaryKeyJoinColumn;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import org.hibernate.annotations.GenericGenerator;
import org.hibernate.annotations.Parameter;
@Entity
@Table(name = "stock_detail", catalog = "mkyongdb")
public class StockDetail implements java.io.Serializable {
private Integer stockId;
private Stock stock;
private String compName;
private String compDesc;
private String remark;
private Date listedDate;
public StockDetail() {
}
public StockDetail(Stock stock, String compName, String compDesc,
String remark, Date listedDate) {
this.stock = stock;
this.compName = compName;
this.compDesc = compDesc;
this.remark = remark;
this.listedDate = listedDate;
}
@GenericGenerator(name = "generator", strategy = "foreign",
parameters = @Parameter(name = "property", value = "stock"))
@Id
@GeneratedValue(generator = "generator")
@Column(name = "STOCK_ID", unique = true, nullable = false)
public Integer getStockId() {
return this.stockId;
}
public void setStockId(Integer stockId) {
this.stockId = stockId;
}
@OneToOne(fetch = FetchType.LAZY)
@PrimaryKeyJoinColumn
public Stock getStock() {
return this.stock;
}
public void setStock(Stock stock) {
this.stock = stock;
}
@Column(name = "COMP_NAME", nullable = false, length = 100)
public String getCompName() {
return this.compName;
}
public void setCompName(String compName) {
this.compName = compName;
}
@Column(name = "COMP_DESC", nullable = false)
public String getCompDesc() {
return this.compDesc;
}
public void setCompDesc(String compDesc) {
this.compDesc = compDesc;
}
@Column(name = "REMARK", nullable = false)
public String getRemark() {
return this.remark;
}
public void setRemark(String remark) {
this.remark = remark;
}
@Temporal(TemporalType.DATE)
@Column(name = "LISTED_DATE", nullable = false, length = 10)
public Date getListedDate() {
return this.listedDate;
}
public void setListedDate(Date listedDate) {
this.listedDate = listedDate;
}
}
3. Файл конфигурации гибернации
Помещает аннотированные классы Stock.java и StockDetail.java в вашем файле конфигурации гибернации, а также сведения о подключении MySQL.
Файл: hibernate.cfg.xml
com.mysql.jdbc.Driver jdbc:mysql://localhost:3306/mkyongdb root password org.hibernate.dialect.MySQLDialect true
4. Запустите Его
Запустите его, Hibernate вставит строку в таблицу ЗАПАСОВ и строку в таблицу STOCK_DETAIL.
Файл: App.java
package com.mkyong;
import java.util.Date;
import org.hibernate.Session;
import com.mkyong.stock.Stock;
import com.mkyong.stock.StockDetail;
import com.mkyong.util.HibernateUtil;
public class App {
public static void main(String[] args) {
System.out.println("Hibernate one to one (Annotation)");
Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction();
Stock stock = new Stock();
stock.setStockCode("7052");
stock.setStockName("PADINI");
StockDetail stockDetail = new StockDetail();
stockDetail.setCompName("PADINI Holding Malaysia");
stockDetail.setCompDesc("one stop shopping");
stockDetail.setRemark("vinci vinci");
stockDetail.setListedDate(new Date());
stock.setStockDetail(stockDetail);
stockDetail.setStock(stock);
session.save(stock);
session.getTransaction().commit();
System.out.println("Done");
}
}
Выход
Hibernate one to one (Annotation) Hibernate: insert into mkyongdb.stock (STOCK_CODE, STOCK_NAME) values (?, ?) Hibernate: insert into mkyongdb.stock_detail (COMP_DESC, COMP_NAME, LISTED_DATE, REMARK, STOCK_ID) values (?, ?, ?, ?, ?) Done
Ссылка
Оригинал: “https://mkyong.com/hibernate/hibernate-one-to-one-relationship-example-annotation/”