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-->URL：http://www.cnblogs.com/fancyzero/archive/2012/06/10/hibernate-one-to-one-annotation.html
環境：
Hibernate 3.3.1
Maven 3.0.4
MySQL 5.5.13
Myeclipse 8.6.1
建表語句：
DROP TABLE IF EXISTS `t_card`;
CREATE TABLE `t_card` (
`cardId` int(10) unsigned NOT NULL AUTO_INCREMENT,
`cardNumber` char(18) NOT NULL,
PRIMARY KEY (`cardId`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=gb2312;
INSERT INTO `t_card` VALUES ('1', '440911199008011122');DROP TABLE IF EXISTS `t_person`;
CREATE TABLE `t_person` (
`personId` int(10) unsigned NOT NULL AUTO_INCREMENT,
`personName` varchar(15) NOT NULL,
`cid` int(10) unsigned NOT NULL,
PRIMARY KEY (`personId`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=gb2312;
INSERT INTO `t_person` VALUES ('1', 'fancy', '1');
Person.java
package com.fancy.po;
import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;
import javax.persistence.Table;
/**
* -----------------------------------------
* @文件: Person.java
* @作者: fancy
* @郵箱: fancyzero@yeah.net
* @時間: 2012-6-10
* @描述: 實體類
* -----------------------------------------
*/
/**
* @Entity 聲明一個類為實體Bean
* @Table(name = "xx")指定實體類映射的表,如果表名和實體類名一致,可以不指定
*/
@Entity
@Table(name = "t_person")
public class Person {
private Integer personId;
private String personName;
private Card card;
/**
* @Id 映射主鍵屬性,這里采用uuid的主鍵生成策略
* @GeneratedValue —— 注解聲明了主鍵的生成策略。該注解有如下屬性
* strategy 指定生成的策略,默認是GenerationType. AUTO
* GenerationType.AUTO 主鍵由程序控制
* GenerationType.TABLE 使用一個特定的數據庫表格來保存主鍵
* GenerationType.IDENTITY 主鍵由數據庫自動生成,主要是自動增長類型
* GenerationType.SEQUENCE 根據底層數據庫的序列來生成主鍵，條件是數據庫支持序列
* generator 指定生成主鍵使用的生成器
*/
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
public Integer getPersonId() {
return personId;
}
/**
* @OneToOne：一對一關聯
* cascade：級聯,它可以有有五個值可選,分別是：
* CascadeType.PERSIST：級聯新建
* CascadeType.REMOVE : 級聯刪除
* CascadeType.REFRESH：級聯刷新
* CascadeType.MERGE ： 級聯更新
* CascadeType.ALL ： 以上全部四項
* @JoinColumn:主表外鍵字段
* cid：Person所映射的表中的一個字段
*/
@OneToOne(cascade = CascadeType.ALL)
@JoinColumn(name = "cid")
public Card getCard() {
return card;
}
public String getPersonName() {
return personName;
}
public void setPersonId(Integer personId) {
this.personId = personId;
}
public void setPersonName(String personName) {
this.personName = personName;
}
public void setCard(Card card) {
this.card = card;
}
}
Card.java
package com.fancy.po;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.OneToOne;
import javax.persistence.Table;
/**
* -----------------------------------------
* @文件: Card.java
* @作者: fancy
* @郵箱: fancyzero@yeah.net
* @時間: 2012-6-10
* @描述: 實體類
* -----------------------------------------
*/
@Entity
@Table(name = "t_card")
public class Card {
private Integer cardId;
private String cardNumber;
private Person person;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
public Integer getCardId() {
return cardId;
}
/**
* @OneToOne：一對一關聯
* mappedBy = "card"：意思是說這里的一對一配置參考了card
* card又是什么呢?card是Person類中的getCard(),注意不是Person類中的
* card屬性,Person類中的OneToOne配置就是在getCard()方法上面配的.
* 如果Person類中的getCard()方法改成getIdCard(),其他不變的話,
* 這里就要寫成：mappedBy = "idCard"
*/
@OneToOne(mappedBy = "card")
public Person getPerson() {
return person;
}
public String getCardNumber() {
return cardNumber;
}
public void setCardId(Integer cardId) {
this.cardId = cardId;
}
public void setCardNumber(String cardNumber) {
this.cardNumber = cardNumber;
}
public void setPerson(Person person) {
this.person = person;
}
}
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.fancy</groupId>
<artifactId>hibernate-annotation-on-to-one-example</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>hibernate-annotation-on-to-one-example</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<!-- hibernate jar -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>3.3.1.ga</version>
</dependency>
<!-- hibernate annotation jar -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-annotations</artifactId>
<version>3.3.1.GA</version>
</dependency>
<!-- mysql -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.17</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
Test.java
package com.fancy.test;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.AnnotationConfiguration;
import org.hibernate.cfg.Configuration;
import com.fancy.po.Card;
import com.fancy.po.Person;
/**
* -----------------------------------------
* @文件: Test.java
* @作者: fancy
* @郵箱: fancyzero@yeah.net
* @時間: 2012-6-10
* @描述: 測試類
* -----------------------------------------
*/
public class Test {
public static void main(String[] args) {
//讀取hibernate配置,默認讀取classpath下的hibernate.cfg.xml
Configuration conf = new AnnotationConfiguration();
//構建session工廠
SessionFactory sessionFactory = conf.configure().buildSessionFactory();
//打開session
Session session = sessionFactory.openSession();
//開始事務
session.beginTransaction();
// * * * * * * * * * * * * * * * * * * * * * * * * * * * *
//test1(session); //測試 1
//test2(session); //測試 2
test3(session); //測試 3
// * * * * * * * * * * * * * * * * * * * * * * * * * * * *
//提交事務
session.getTransaction().commit();
//關閉session工廠
sessionFactory.close();
//關閉session
session.close();
}
/**
* 數據庫初始值：
* personName：fancy
* cardNumber：440911199008011122
*/
//測試方法1
public static void test1(Session session){
Person person = (Person)session.get(Person.class, 1); //發出Person和Card的select語句
Card card = person.getCard();
System.out.println(person.getPersonName());
System.out.println(card.getCardNumber());
person.setPersonName("fancy"); //與初始值一致
card.setCardNumber("440911199008011122");//與初始值一致
session.save(person); //不發出sql語句
//session.save(card); //不發出sql語句
}
//測試方法2
public static void test2(Session session){
Person person = (Person)session.get(Person.class, 1); //發出Person和Card的select語句
Card card = person.getCard();
System.out.println(person.getPersonName());
System.out.println(card.getCardNumber());
person.setPersonName("fancyzero"); //與初始值不一致
card.setCardNumber("440911199008011122");//與初始值一致
session.save(person); //發出Person的update語句,數據庫中personName被修改,不發出Card的update語句
//session.save(card); //發出Person的update語句,數據庫中personName被修改,不發出Card的update語句
}
//測試方法3
public static void test3(Session session){
Person person = (Person)session.get(Person.class, 1); //發出Person和Card的select語句
Card card = person.getCard();
System.out.println(person.getPersonName());
System.out.println(card.getCardNumber());
person.setPersonName("fancy"); //與初始值不一致
card.setCardNumber("440911199008080808");//與初始值不一致
session.save(person); //同時發出Person和Card的update語句,數據庫中的數據相應被修改
//session.save(card); //同時發出Person和Card的update語句,數據庫中的數據相應被修改
}
}
posted on 2012-06-10 14:34
fancydeepin 閱讀(914)
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