Автор оригинала: mkyong.
В этом учебном пособии будет повторно использована вся инфраструктура предыдущего ” Пример гибернации от одного до многих отношений – сопоставление XML ” учебника, улучшите его для поддержки аннотации Hibernate/JPA.
Структура проекта
Ознакомьтесь с новой структурой проекта этого руководства.
1. ” Отношение таблицы “Один ко многим”
См. предыдущее отношение таблицы “один ко многим” еще раз.
2. Класс модели гибернации
Обновить предыдущие классы моделей – Stock.java и StockDailyRecord.java , и определите код аннотации внутри.
Файл: Stock.java
package com.mkyong.stock;
import java.util.HashSet;
import java.util.Set;
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.OneToMany;
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 Set stockDailyRecords = new HashSet(
0);
public Stock() {
}
public Stock(String stockCode, String stockName) {
this.stockCode = stockCode;
this.stockName = stockName;
}
public Stock(String stockCode, String stockName,
Set stockDailyRecords) {
this.stockCode = stockCode;
this.stockName = stockName;
this.stockDailyRecords = stockDailyRecords;
}
@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;
}
@OneToMany(fetch = FetchType.LAZY, mappedBy = "stock")
public Set getStockDailyRecords() {
return this.stockDailyRecords;
}
public void setStockDailyRecords(Set stockDailyRecords) {
this.stockDailyRecords = stockDailyRecords;
}
}
Файл: StockDailyRecord.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 static javax.persistence.GenerationType.IDENTITY;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import javax.persistence.UniqueConstraint;
@Entity
@Table(name = "stock_daily_record", catalog = "mkyongdb",
uniqueConstraints = @UniqueConstraint(columnNames = "DATE"))
public class StockDailyRecord implements java.io.Serializable {
private Integer recordId;
private Stock stock;
private Float priceOpen;
private Float priceClose;
private Float priceChange;
private Long volume;
private Date date;
public StockDailyRecord() {
}
public StockDailyRecord(Stock stock, Date date) {
this.stock = stock;
this.date = date;
}
public StockDailyRecord(Stock stock, Float priceOpen, Float priceClose,
Float priceChange, Long volume, Date date) {
this.stock = stock;
this.priceOpen = priceOpen;
this.priceClose = priceClose;
this.priceChange = priceChange;
this.volume = volume;
this.date = date;
}
@Id
@GeneratedValue(strategy = IDENTITY)
@Column(name = "RECORD_ID", unique = true, nullable = false)
public Integer getRecordId() {
return this.recordId;
}
public void setRecordId(Integer recordId) {
this.recordId = recordId;
}
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "STOCK_ID", nullable = false)
public Stock getStock() {
return this.stock;
}
public void setStock(Stock stock) {
this.stock = stock;
}
@Column(name = "PRICE_OPEN", precision = 6)
public Float getPriceOpen() {
return this.priceOpen;
}
public void setPriceOpen(Float priceOpen) {
this.priceOpen = priceOpen;
}
@Column(name = "PRICE_CLOSE", precision = 6)
public Float getPriceClose() {
return this.priceClose;
}
public void setPriceClose(Float priceClose) {
this.priceClose = priceClose;
}
@Column(name = "PRICE_CHANGE", precision = 6)
public Float getPriceChange() {
return this.priceChange;
}
public void setPriceChange(Float priceChange) {
this.priceChange = priceChange;
}
@Column(name = "VOLUME")
public Long getVolume() {
return this.volume;
}
public void setVolume(Long volume) {
this.volume = volume;
}
@Temporal(TemporalType.DATE)
@Column(name = "DATE", unique = true, nullable = false, length = 10)
public Date getDate() {
return this.date;
}
public void setDate(Date date) {
this.date = date;
}
}
3. Файл конфигурации гибернации
Помещает аннотированные классы Stock.java и StockDailyRecord.java в hibernate.cfg.xml вот так:
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_DAILY_RECORD.
Файл: App.java
package com.mkyong;
import java.util.Date;
import org.hibernate.Session;
import com.mkyong.stock.Stock;
import com.mkyong.stock.StockDailyRecord;
import com.mkyong.util.HibernateUtil;
public class App {
public static void main(String[] args) {
System.out.println("Hibernate one to many (Annotation)");
Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction();
Stock stock = new Stock();
stock.setStockCode("7052");
stock.setStockName("PADINI");
session.save(stock);
StockDailyRecord stockDailyRecords = new StockDailyRecord();
stockDailyRecords.setPriceOpen(new Float("1.2"));
stockDailyRecords.setPriceClose(new Float("1.1"));
stockDailyRecords.setPriceChange(new Float("10.0"));
stockDailyRecords.setVolume(3000000L);
stockDailyRecords.setDate(new Date());
stockDailyRecords.setStock(stock);
stock.getStockDailyRecords().add(stockDailyRecords);
session.save(stockDailyRecords);
session.getTransaction().commit();
System.out.println("Done");
}
}
Выход
Hibernate one to many (Annotation)
Hibernate:
insert
into
mkyongdb.stock
(STOCK_CODE, STOCK_NAME)
values
(?, ?)
Hibernate:
insert
into
mkyongdb.stock_daily_record
(DATE, PRICE_CHANGE, PRICE_CLOSE, PRICE_OPEN, STOCK_ID, VOLUME)
values
(?, ?, ?, ?, ?, ?)
Done
Ссылка
Оригинал: “https://mkyong.com/hibernate/hibernate-one-to-many-relationship-example-annotation/”