Hibernate，JPA注解@OneToOne_JoinColumn-蒲公英云

一对一(One-to-one)，外键关联

用例代码如下：

数据库DDL语句

1，CAT表

1 create table CAT
 2 (
 3   id          VARCHAR2(32 CHAR) not null,
 4   create_time TIMESTAMP(6),
 5   update_time TIMESTAMP(6),
 6   cat_name    VARCHAR2(255 CHAR),
 7   first_name  VARCHAR2(255 CHAR),
 8   last_name   VARCHAR2(255 CHAR),
 9   version     NUMBER(10) not null
10 )

2，CAT_INFO表

1 create table CAT_INFO
2 (
3   id          VARCHAR2(32 CHAR) not null,
4   create_time TIMESTAMP(6),
5   update_time TIMESTAMP(6),
6   address     VARCHAR2(255 CHAR),
7   birthday    TIMESTAMP(6),
8   cat_id      VARCHAR2(32 CHAR)
9 )

hibernate.cfg.xml

1 <?xml version=”1.0” encoding=”utf-8” ?>
2 <!DOCTYPE hibernate-configuration
3 PUBLIC “-//Hibernate/Hibernate Configuration DTD//EN”
4 “http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
5
6
7
8 org.hibernate.dialect.Oracle10gDialect
9 oracle.jdbc.OracleDriver
10 jdbcthin:@127.0.0.1orcl
11 wxuatuser
12 xlh
13 true
14
15 update
16
17
18
19
20
21
22
java类

实体类 - 基类

1 package model;
 2 import java.io.Serializable;
 3 import java.util.Date;
 4 import javax.persistence.Column;
 5 import javax.persistence.GeneratedValue;
 6 import javax.persistence.Id;
 7 import javax.persistence.MappedSuperclass;
 8 import org.hibernate.annotations.GenericGenerator;
 9 /**
10  * 实体类 - 基类
11  */
12 @MappedSuperclass
13 public class BaseEntity implements Serializable {
14 
15     private static final long serialVersionUID = -6718838800112233445L;
16 
17     private String id;// ID
18     private Date create_time;// 创建日期
19     private Date update_time;// 修改日期
20     @Id
21     @Column(length = 32, nullable = true)
22     @GeneratedValue(generator = "uuid")
23     @GenericGenerator(name = "uuid", strategy = "uuid")
24     public String getId() {
25         return id;
26     }
27     public void setId(String id) {
28         this.id = id;
29     }
30     @Column(updatable = false)
31     public Date getCreate_time() {
32         return create_time;
33     }
34     public void setCreate_time(Date create_time) {
35         this.create_time = create_time;
36     }
37     public Date getUpdate_time() {
38         return update_time;
39     }
40     public void setUpdate_time(Date update_time) {
41         this.update_time = update_time;
42     }
43     @Override
44     public int hashCode() {
45         return id == null ? System.identityHashCode(this) : id.hashCode();
46     }
47     @Override
48     public boolean equals(Object obj) {
49         if (this == obj) {
50             return true;
51         }
52         if (obj == null) {
53             return false;
54         }
55         if (getClass().getPackage() != obj.getClass().getPackage()) {
56             return false;
57         }
58         final BaseEntity other = (BaseEntity) obj;
59         if (id == null) {
60             if (other.getId() != null) {
61                 return false;
62             }
63         } else if (!id.equals(other.getId())) {
64             return false;
65         }
66         return true;
67     }
68 }

实体类

Cat.java

1 package a7_OneToOne_JoinColumn;
 2 import javax.persistence.AttributeOverride;
 3 import javax.persistence.AttributeOverrides;
 4 import javax.persistence.CascadeType;
 5 import javax.persistence.Column;
 6 import javax.persistence.Embedded;
 7 import javax.persistence.Entity;
 8 import javax.persistence.JoinColumn;
 9 import javax.persistence.OneToOne;
10 import javax.persistence.Version;
11 import model.BaseEntity;
12 import org.hibernate.annotations.DynamicInsert;
13 import org.hibernate.annotations.DynamicUpdate;
14 
15 @Entity
16 @DynamicInsert
17 @DynamicUpdate
18 public class Cat extends BaseEntity{
19     /**
20      * 实体类
21      */
22     private static final long serialVersionUID = -2776330321385582872L;
23     
24     private Cat_Info cat_Info;
25 
26     private String cat_name;
27     private Name name;
28     private int version;
29 
30     @Version
31     public int getVersion() {
32         return version;
33     }
34 
35     public void setVersion(int version) {
36         this.version = version;
37     }
38 
39     public String getCat_name() {
40         return cat_name;
41     }
42 
43     public void setCat_name(String cat_name) {
44         this.cat_name = cat_name;
45     }
46 
47     @Embedded
48     @AttributeOverrides({
49             @AttributeOverride(name = "first_name", column = @Column(name = "first_name")),
50             @AttributeOverride(name = "last_name", column = @Column(name = "last_name")) })
51     public Name getName() {
52         return name;
53     }
54 
55     public void setName(Name name) {
56         this.name = name;
57     }
58 
59     /*
60      * mappedBy属性：
61      * 如果关系是单向的，则该关联提供程序确定拥有该关系的字段。
62      * 如果关系是双向的，则将关联相反（非拥有）方上的 mappedBy 元素设置为拥
63      * 有此关系的字段或属性的名称
64      */
65     @OneToOne(cascade = CascadeType.ALL,mappedBy="cat") 
66     @JoinColumn(name="id", referencedColumnName="id", unique=true, nullable=false, updatable=true)
67     public Cat_Info getCat_Info() {
68         return cat_Info;
69     }
70 
71     public void setCat_Info(Cat_Info cat_Info) {
72         this.cat_Info = cat_Info;
73     }
74 }

Cat_Info.java

1 package a7_OneToOne_JoinColumn;
 2 import java.util.Date;
 3 import javax.persistence.CascadeType;
 4 import javax.persistence.Entity;
 5 import javax.persistence.FetchType;
 6 import javax.persistence.OneToOne;
 7 import model.BaseEntity;
 8 
 9 @Entity
10 public class Cat_Info extends BaseEntity{
11     /**
12      * 
13      */
14     private static final long serialVersionUID = 8258082211095664606L;
15 
16     private Cat cat;
17     private String address;
18     private Date birthday;
19 
20     public String getAddress() {
21         return address;
22     }
23 
24     public void setAddress(String address) {
25         this.address = address;
26     }
27 
28     public Date getBirthday() {
29         return birthday;
30     }
31 
32     public void setBirthday(Date birthday) {
33         this.birthday = birthday;
34     }
35     
36     
37     @OneToOne(cascade = {CascadeType.ALL},fetch = FetchType.EAGER)
38     public Cat getCat() {
39         return cat;
40     }
41 
42     public void setCat(Cat cat) {
43         this.cat = cat;
44     }
45 }

组件类

1 package a7_OneToOne_JoinColumn;
 2 import java.io.Serializable;
 3 import javax.persistence.Embeddable;
 4 
 5 @Embeddable
 6 public class Name implements Serializable {
 7     /**
 8      * 嵌入式组建
 9      */
10     private static final long serialVersionUID = -2776330321385582872L;
11     
12     private String first_name;
13     private String last_name;
14     public String getFirst_name() {
15         return first_name;
16     }
17     public void setFirst_name(String first_name) {
18         this.first_name = first_name;
19     }
20     public String getLast_name() {
21         return last_name;
22     }
23     public void setLast_name(String last_name) {
24         this.last_name = last_name;
25     }
26 }

Dao

1 package daoUtil;
 2 import org.hibernate.HibernateException;
 3 import org.hibernate.Session;
 4 import org.hibernate.SessionFactory;
 5 import org.hibernate.Transaction;
 6 import org.hibernate.cfg.Configuration;
 7 import org.hibernate.service.ServiceRegistry;
 8 import org.hibernate.service.ServiceRegistryBuilder;
 9 
10 public class HibernateUtil {
11 
12     private static final SessionFactory sessionFactory;
13 
14     static {
15         try {
16             Configuration cfg = new Configuration().configure();
17             ServiceRegistry serviceRegistry = new ServiceRegistryBuilder()
18                     .applySettings(cfg.getProperties()).buildServiceRegistry();
19             sessionFactory = cfg.buildSessionFactory(serviceRegistry);
20         } catch (Throwable ex) {
21             throw new ExceptionInInitializerError(ex);
22         }
23     }
24 
25     public static Session getSession() throws HibernateException {
26         return sessionFactory.openSession();
27     }
28 
29     public static Object save(Object obj){
30         Session session = HibernateUtil.getSession();
31         Transaction tx = null;
32         try {
33             tx = session.beginTransaction();
34             session.save(obj);
35             tx.commit();
36         } catch (RuntimeException e) {
37             if (tx != null) {
38                 tx.rollback();
39             }
40             throw e;
41         } finally {
42             session.close();
43         }
44         return obj;
45     }
46     
47     public static void delete(Class<?> clazz,String id){
48         Session session = HibernateUtil.getSession();
49         Transaction tx = null;
50         try {
51             tx = session.beginTransaction();
52             Object obj = session.get(clazz,id);
53             session.delete(obj);
54             tx.commit();
55         } catch (RuntimeException e) {
56             if (tx != null) {
57                 tx.rollback();
58             }
59             throw e;
60         } finally {
61             session.close();
62         }
63     }
64 }

main

1 package a7_OneToOne_JoinColumn;
 2 import java.util.Date;
 3 import daoUtil.HibernateUtil;
 4 
 5 public class Test_OneToOne_JoinColumn {
 6 
 7     private Cat save(){
 8     
 9         Cat_Info info = new Cat_Info();
10         info.setAddress("201503291");
11         info.setBirthday(new Date());
12 
13         Cat cat = new Cat();
14         cat.setCat_name("a7_OneToOne_JoinColumn");
15         cat.setName(new Name());
16         cat.setCat_Info(info);
17         info.setCat(cat);
18         
19         HibernateUtil.save(info);
20         System.out.println(cat.getId());
21         return cat;
22     }
23     
24     public static void main(String[] args) {
25         
26         Cat cat = new Test_OneToOne_JoinColumn().save();
27         Cat cat1 = (Cat)HibernateUtil.getSession().get(Cat.class, cat.getId());
28         System.out.println(cat1.getId());
29         
30         Cat_Info cat_Info = (Cat_Info)HibernateUtil.getSession().get(Cat_Info.class, cat1.getCat_Info().getId());
31         System.out.println(cat_Info.getId());
32     }
33 }