1.基于(foreign key)外鍵實現

國家<-------->首都

Country.java

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1 package hibernate.orm.one2one.fk; 2 3 import javax.persistence.Column; 4 import javax.persistence.Entity; 5 import javax.persistence.GeneratedValue; 6 import javax.persistence.Id; 7 import javax.persistence.JoinColumn; 8 import javax.persistence.OneToOne; 9 import javax.persistence.PrimaryKeyJoinColumn; 10 import javax.persistence.Table; 11 12 import org.hibernate.annotations.GenericGenerator; 13 // 主表 14 // 被擁有方 15 @Entity 16 @Table(name = "t_country") 17 public class Country { 18 private Long id; 19 private String name; 20 private Capital capital; 21 22 public Country() { 23 } 24 25 @Id 26 @Column(length=8) 27 @GenericGenerator(name = "ud", strategy = "increment") 28 // 主鍵生成器 29 @GeneratedValue(generator = "ud") 30 public Long getId() { 31 return id; 32 } 33 34 public void setId(Long id) { 35 this.id = id; 36 } 37 38 @Column(length = 20) 39 public String getName() { 40 return name; 41 } 42 43 public void setName(String name) { 44 this.name = name; 45 } 46 @OneToOne(mappedBy="country",optional=true)//一個國家可以沒有首都 47 //表示當前所在表和Capital的關系是定義在Capital里面的country這個成員上面的,它表示此表是一對一關系中的主表 48 public Capital getCapital() { 49 return capital; 50 } 51 52 public void setCapital(Capital capital) { 53 this.capital = capital; 54 } 55 56 }

?Capital.java

1 package hibernate.orm.one2one.fk; 2 3 import javax.persistence.Column; 4 import javax.persistence.Entity; 5 import javax.persistence.GeneratedValue; 6 import javax.persistence.GenerationType; 7 import javax.persistence.Id; 8 import javax.persistence.JoinColumn; 9 import javax.persistence.OneToOne; 10 import javax.persistence.PrimaryKeyJoinColumn; 11 import javax.persistence.Table; 12 13 import org.hibernate.annotations.GenericGenerator; 14 //從表 15 //擁有方 16 @Entity 17 @Table(name = "t_capital") 18 public class Capital { 19 private Long id; 20 private String name; 21 private Country country; 22 23 public Capital() { 24 } 25 26 @Id 27 @Column(length=8) 28 @GenericGenerator(name="ud",strategy="increment") 29 @GeneratedValue(generator="ud") 30 public Long getId() { 31 return id; 32 } 33 34 public void setId(Long id) { 35 this.id = id; 36 } 37 @Column(length=20) 38 public String getName() { 39 return name; 40 } 41 42 public void setName(String name) { 43 this.name = name; 44 } 45 @OneToOne(optional=false)//一個首都必對應一個國家 46 @JoinColumn(name="country_id") 47 public Country getCountry() { 48 return country; 49 } 50 51 public void setCountry(Country country) { 52 this.country = country; 53 } 54 55 }

One2OneTest.java(測試類)

package hibernate.orm.one2one.fk;import hibernate.util.HibernateSessionFactory;import org.hibernate.Session; import org.hibernate.Transaction;public class One2OneTest {public static void main(String[] args) {Session session = HibernateSessionFactory.getSession();Transaction tx = session.beginTransaction();Country country = new Country();country.setName("中國");Capital capital = new Capital();capital.setName("北京");country.setCapital(capital);capital.setCountry(country);//相互建立關聯 session.save(country);session.save(capital);tx.commit();HibernateSessionFactory.closeSession();} }

hibernate.cfg.xml

<?xml version='1.0' encoding='UTF-8'?> <!DOCTYPE hibernate-configuration PUBLIC"-//Hibernate/Hibernate Configuration DTD 3.0//EN""http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"> <hibernate-configuration><session-factory><property name="dialect">org.hibernate.dialect.Oracle10gDialect</property><property name="connection.url">jdbc:oracle:thin:@127.0.0.1:1521:xe</property><property name="connection.username">hibernate</property><property name="connection.password">123</property><property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property><!-- <property name="javax.persistence.validation.mode">none</property> --><property name="current_session_context_class">thread</property><property name="show_sql">true</property><property name="format_sql">true</property><property name="hbm2ddl.auto">create</property><!-- 自動建表 --><mapping class="hibernate.orm.one2one.fk.Country"/><mapping class="hibernate.orm.one2one.fk.Capital"/></session-factory> </hibernate-configuration>

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2.基于(primary key)主鍵實現

丈夫<-------->妻子

Husband.java

1 package hibernate.orm.one2one.pk; 2 3 import javax.persistence.Column; 4 import javax.persistence.Entity; 5 import javax.persistence.GeneratedValue; 6 import javax.persistence.Id; 7 import javax.persistence.OneToOne; 8 import javax.persistence.PrimaryKeyJoinColumn; 9 import javax.persistence.Table; 10 11 import org.hibernate.annotations.GenericGenerator; 12 import org.hibernate.annotations.Parameter; 13 14 @Entity 15 @Table(name = "t_husband") 16 public class Husband { 17 private Long id; 18 private String name; 19 private Wife wife; 20 21 @Id 22 @GenericGenerator(name = "ud", strategy = "foreign", parameters = { @Parameter(name = "property", value = "wife") }) 23 @GeneratedValue(generator = "ud") 24 public Long getId() { 25 return id; 26 } 27 28 public void setId(Long id) { 29 this.id = id; 30 } 31 @Column(length=20) 32 public String getName() { 33 return name; 34 } 35 36 public void setName(String name) { 37 this.name = name; 38 } 39 @OneToOne 40 @PrimaryKeyJoinColumn 41 public Wife getWife() { 42 return wife; 43 } 44 45 public void setWife(Wife wife) { 46 this.wife = wife; 47 } 48 49 }

Wife.java

1 package hibernate.orm.one2one.pk; 2 3 import javax.persistence.Column; 4 import javax.persistence.Entity; 5 import javax.persistence.GeneratedValue; 6 import javax.persistence.Id; 7 import javax.persistence.OneToOne; 8 import javax.persistence.Table; 9 10 import org.hibernate.annotations.GenericGenerator; 11 12 @Entity 13 @Table(name = "t_wife") 14 public class Wife { 15 private Long id; 16 private String name; 17 private Husband husband; 18 19 @Id 20 @GenericGenerator(name = "ud", strategy = "increment") 21 @GeneratedValue(generator = "ud") 22 public Long getId() { 23 return id; 24 } 25 26 public void setId(Long id) { 27 this.id = id; 28 } 29 30 @Column(length = 20) 31 public String getName() { 32 return name; 33 } 34 35 public void setName(String name) { 36 this.name = name; 37 } 38 @OneToOne(mappedBy="wife")//表之間的關系由Husband類中的wife屬性維護 39 public Husband getHusband() { 40 return husband; 41 } 42 43 public void setHusband(Husband husband) { 44 this.husband = husband; 45 } 46 47 }

?One2OneTest.java

1 package hibernate.orm.one2one.pk; 2 3 import hibernate.util.HibernateSessionFactory; 4 5 import org.hibernate.Session; 6 import org.hibernate.Transaction; 7 8 public class One2OneTest { 9 public static void main(String[] args) { 10 Session session = HibernateSessionFactory.getSession(); 11 Transaction tx = session.beginTransaction(); 12 Husband husband = new Husband(); 13 husband.setName("陽陽"); 14 Wife wife = new Wife(); 15 wife.setName("原原"); 16 husband.setWife(wife); 17 wife.setHusband(husband);//設置雙向關聯關系 18 session.save(husband); 19 session.save(wife); 20 tx.commit(); 21 HibernateSessionFactory.closeSession(); 22 23 } 24 }

hibernate.cfg.xml

<?xml version='1.0' encoding='UTF-8'?> <!DOCTYPE hibernate-configuration PUBLIC"-//Hibernate/Hibernate Configuration DTD 3.0//EN""http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"> <hibernate-configuration><session-factory><property name="dialect">org.hibernate.dialect.Oracle10gDialect</property><property name="connection.url">jdbc:oracle:thin:@127.0.0.1:1521:xe</property><property name="connection.username">hibernate</property><property name="connection.password">123</property><property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property><!-- <property name="javax.persistence.validation.mode">none</property> --><property name="current_session_context_class">thread</property><property name="show_sql">true</property><property name="format_sql">true</property><property name="hbm2ddl.auto">create</property><!-- 自動建表 --><mapping class="hibernate.orm.one2one.pk.Husband"/><mapping class="hibernate.orm.one2one.pk.Wife"/></session-factory> </hibernate-configuration>

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轉載于:https://www.cnblogs.com/wuyulunbi/archive/2012/12/21/hibernate_2.html

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