Hibernate一对一数据关联:唯一外键关联

Hibernate一对一数据关联：唯一外键关联
一.单向一对一关联
1.数据模型如下图所示：


2.数据表sql
DROPTABLET_User;
DROPTABLET_Group;

CREATETABLET_Group(
idINTNOTNULLAUTO_INCREMENT
,nameVARCHAR(50)
,PRIMARYKEY(id)
);

CREATETABLET_User(
idINTNOTNULLAUTO_INCREMENT
,nameVARCHAR(50)
,ageINT
,group_idINTNOTNULL
,PRIMARYKEY(id)
,INDEX(group_id)
,CONSTRAINTFK_T_User_1FOREIGNKEY(group_id)
REFERENCEST_Group(id)
);

</DIV>
3.POJO类
TUser.java
packagecom.jeff.wap.bo;

publicclassTUserimplementsjava.io.Serializable{
//Fields
privateIntegerid;
privateIntegerage;
privateStringname;
privateTGroupgroup;


//Constructors

publicIntegergetAge(){
returnage;
}

publicvoidsetAge(Integerage){
this.age=age;
}


publicTGroupgetGroup(){
returngroup;
}

publicvoidsetGroup(TGroupgroup){
this.group=group;
}

/**defaultconstructor*/
publicTUser(){
}

/**constructorwithid*/
publicTUser(Integerid){
this.id=id;
}

//Propertyaccessors

publicIntegergetId(){
returnthis.id;
}

publicvoidsetId(Integerid){
this.id=id;
}

publicStringgetName(){
returnthis.name;
}

publicvoidsetName(Stringname){
this.name=name;
}
}
TGroup.java
packagecom.jeff.wap.bo;

importjava.io.Serializable;

publicclassTGroupimplementsSerializable{

privateIntegerid;
privateStringname;

publicIntegergetId(){
returnid;
}
publicvoidsetId(Integerid){
this.id=id;
}
publicStringgetName(){
returnname;
}
publicvoidsetName(Stringname){
this.name=name;
}

}
</DIV>
3.配置文件
hibernate.cfg.xml
<?xmlversion="1.0"encoding="UTF-8"?>
<!DOCTYPEhibernate-configurationPUBLIC
"-//Hibernate/HibernateConfigurationDTD3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<propertyname="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<propertyname="hibernate.connection.password">pwd</property>
<propertyname="hibernate.connection.url">jdbc:mysql://localhost:3306/sample</property>
<propertyname="hibernate.connection.username">root</property>
<propertyname="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<mappingresource="com/jeff/wap/bo/TUser.hbm.xml"/>
<mappingresource="com/jeff/wap/bo/TGroup.hbm.xml"/>
</session-factory>
</hibernate-configuration>
</DIV>
TGroup.hbm.xml
<?xmlversion="1.0"?>
<!DOCTYPEhibernate-mappingPUBLIC"-//Hibernate/HibernateMappingDTD3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<classname="com.jeff.wap.bo.TGroup"table="T_Group"catalog="sample">
<idname="id"type="integer">
<columnname="id"/>
<generatorclass="native"/>
</id>
<propertyname="name"type="string"column="name"/>
</class>
</hibernate-mapping>
</DIV>
TUser.hbm.xml
<?xmlversion="1.0"?>
<!DOCTYPEhibernate-mappingPUBLIC"-//Hibernate/HibernateMappingDTD3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<classname="com.jeff.wap.bo.TUser"table="T_User"catalog="sample">
<idname="id"type="integer">
<columnname="id"/>
<generatorclass="native"/>
</id>
<propertyname="name"type="string">
<columnname="name"length="100"not-null="true"/>
</property>
<propertyname="age"type="java.lang.Integer"column="age"/>
<many-to-onename="group"
class="com.jeff.wap.bo.TGroup"
column="group_id"
cascade="all"
unique="true"
/>
</class>
</hibernate-mapping>
</DIV>
4.测试代码
packagecom.jeff.wap.bo;

importjava.util.List;

importjunit.framework.Assert;
importjunit.framework.TestCase;

importorg.hibernate.HibernateException;
importorg.hibernate.Session;
importorg.hibernate.SessionFactory;
importorg.hibernate.Transaction;
importorg.hibernate.cfg.Configuration;


publicclassHibernateTestextendsTestCase{

Sessionsession=null;

protectedvoidsetUp(){
try{
Configurationconfig=newConfiguration().configure();
SessionFactorysessionFactory=config.buildSessionFactory();
session=sessionFactory.openSession();

}catch(HibernateExceptione){
e.printStackTrace();
}
}

protectedvoidtearDown(){
try{
session.close();
}catch(HibernateExceptione){
e.printStackTrace();
}
}

/**
*对象持久化测试(Insert方法)
*/
publicvoidtestInsert(){
Transactiontran=null;
try{

TUseruser=newTUser();
user.setName("byf");
user.setAge(newInteger(26));

TGroupgroup=newTGroup();
group.setName("Admin");

// 如果在配置文件中没有cascade="all",测试就会报错

tran=session.beginTransaction();
//设置关联
user.setGroup(group);

//插入user信息
session.save(user);
session.flush();
tran.commit();
Assert.assertEquals(user.getId().intValue()>0,true);
}catch(HibernateExceptione){
e.printStackTrace();
Assert.fail(e.getMessage());
if(tran!=null){
try{
tran.rollback();
}catch(Exceptione1){
e1.printStackTrace();
}
}
}
}

/**
*对象读取测试(Select方法)
*/
publicvoidtestSelect(){
Stringhql="fromTUserwherename='byf'";
try{
ListuserList=session.createQuery(hql).list();
TUseruser=(TUser)userList.get(0);
System.out.println("usernameis"+user.getName());
System.out.println("usergroupis"+user.getGroup().getName());
Assert.assertEquals(user.getName(),"byf");
}catch(Exceptione){
e.printStackTrace();
Assert.fail(e.getMessage());
}
}
}