Hibernate –多対多の例（注釈）
このチュートリアルでは、前の「http://www.example.com/hibernate/hibernate-many-to-many-relationship-example/ [Hibernate多対多の例–XMLマッピング]」チュートリアルのインフラストラクチャ全体を再利用します。 、Hibernare / JPAアノテーションをサポートするように拡張します。
Note
結合テーブルに余分な列がある多対多の場合は、このtutorialを参照してください。
プロジェクト構造
このチュートリアルの新しいプロジェクト構造を確認してください。
1. 「多対多」テーブルの関係
前の多対多テーブルの関係をもう一度参照してください。
2. Hibernateモデルクラス
以前のモデルクラス–Stock.javaおよびCategory.javaを更新し、内部に新しい注釈コードを定義します。
ファイル：Stock.java
package com.example.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.CascadeType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.Table;
import javax.persistence.UniqueConstraint;
@Entity
@Table(name = "stock", catalog = "exampledb", 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 categories = new HashSet(0);
public Stock() {
}
public Stock(String stockCode, String stockName) {
this.stockCode = stockCode;
this.stockName = stockName;
}
public Stock(String stockCode, String stockName, Set categories) {
this.stockCode = stockCode;
this.stockName = stockName;
this.categories = categories;
}
@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;
}
@ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
@JoinTable(name = "stock_category", catalog = "exampledb", joinColumns = {
@JoinColumn(name = "STOCK_ID", nullable = false, updatable = false) },
inverseJoinColumns = { @JoinColumn(name = "CATEGORY_ID",
nullable = false, updatable = false) })
public Set getCategories() {
return this.categories;
}
public void setCategories(Set categories) {
this.categories = categories;
}
}
ファイル：Category.java
package com.example.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.ManyToMany;
import javax.persistence.Table;
@Entity
@Table(name = "category", catalog = "exampledb")
public class Category implements java.io.Serializable {
private Integer categoryId;
private String name;
private String desc;
private Set stocks = new HashSet(0);
public Category() {
}
public Category(String name, String desc) {
this.name = name;
this.desc = desc;
}
public Category(String name, String desc, Set stocks) {
this.name = name;
this.desc = desc;
this.stocks = stocks;
}
@Id
@GeneratedValue(strategy = IDENTITY)
@Column(name = "CATEGORY_ID", unique = true, nullable = false)
public Integer getCategoryId() {
return this.categoryId;
}
public void setCategoryId(Integer categoryId) {
this.categoryId = categoryId;
}
@Column(name = "NAME", nullable = false, length = 10)
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
@Column(name = "[DESC]", nullable = false)
public String getDesc() {
return this.desc;
}
public void setDesc(String desc) {
this.desc = desc;
}
@ManyToMany(fetch = FetchType.LAZY, mappedBy = "categories")
public Set getStocks() {
return this.stocks;
}
public void setStocks(Set stocks) {
this.stocks = stocks;
}
}
3. Hibernate設定ファイル
注釈付きクラスStock.javaとCategory.javaを次のようにhibernate.cfg.xmlに配置します：
ファイル：hibernate.cfg.xml
com.mysql.jdbc.Driver jdbc:mysql://localhost:3306/exampledb root password org.hibernate.dialect.MySQLDialect true
4. それを実行します
実行すると、結果は一目瞭然です。
ファイル：App.java
package com.example;
import java.util.HashSet;
import java.util.Set;
import org.hibernate.Session;
import com.example.stock.Category;
import com.example.stock.Stock;
import com.example.util.HibernateUtil;
public class App {
public static void main(String[] args) {
System.out.println("Hibernate many to many (Annotation)");
Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction();
Stock stock = new Stock();
stock.setStockCode("7052");
stock.setStockName("PADINI");
Category category1 = new Category("CONSUMER", "CONSUMER COMPANY");
Category category2 = new Category("INVESTMENT", "INVESTMENT COMPANY");
Set categories = new HashSet();
categories.add(category1);
categories.add(category2);
stock.setCategories(categories);
session.save(stock);
session.getTransaction().commit();
System.out.println("Done");
}
}
出力
Hibernate many to many (Annotation)
Hibernate:
insert
into
exampledb.stock
(STOCK_CODE, STOCK_NAME)
values
(?, ?)
Hibernate:
insert
into
exampledb.category
(`DESC`, NAME)
values
(?, ?)
Hibernate:
insert
into
exampledb.category
(`DESC`, NAME)
values
(?, ?)
Hibernate:
insert
into
exampledb.stock_category
(STOCK_ID, CATEGORY_ID)
values
(?, ?)
Hibernate:
insert
into
exampledb.stock_category
(STOCK_ID, CATEGORY_ID)
values
(?, ?)
Done
ダウンロード–Hibernate-many-to-many-annotation.zip（9KB）