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 <hibernate-configuration>
6 <session-factory>
7 <!-- 数据库驱动配置 -->
8 <property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>
9 <property name="connection.driver_class">oracle.jdbc.OracleDriver</property>
10 <property name="connection.url">jdbc:oracle:thin:@127.0.0.1:1521:orcl</property>
11 <property name="connection.username">wxuatuser</property>
12 <property name="connection.password">xlh</property>
13 <property name="show_sql">true</property>
14 <!-- 自动执行DDL属性是update,不是true -->
15 <property name="hbm2ddl.auto">update</property>
16 <!-- hibernate实体类 -->
17
18 <mapping class="a7_OneToOne_JoinColumn.Cat"/>
19 <mapping class="a7_OneToOne_JoinColumn.Cat_Info"/>
20
21 </session-factory>
22 </hibernate-configuration>


  • 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 }