Hibernate的一對一關系

2019-11-18 14:42:55

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　　Hibernate的一對一關系

一對一關系的維護有兩種，分為主鍵關聯和唯一外鍵關聯

主鍵關聯：（雙向）
(主控方)

Person.java
Person {

PRivate String username;
//對被控方的引用
private Address address;

public String getUsername() {
return username;
}

public void setUsername(String username) {
this.username = username;
}

public Address getAddress() {
return address;
}

public void setAddress(Address address) {
this.address= address;
}

}

(被動方)
Address.java
Address{

private String addressName;
//對主控方的引用
private Person person;

public String getAddressName() {
return addressName;
}

public void setAddressName(String addressName) {
this.addressName= addressName;
}

public Person getPerson() {
return person;
}

public void setPerson(Person person) {
this.person= person;
}

public String toString() {
return new ToStringBuilder(this).
append("addressName", addressName).
toString();
}

public boolean equals(Object o) {
if ( !(o instanceof Address) {
return false;
}
Address rhs = (Address) o;
return new EqualsBuilder()
.appendSuper(super.equals(o))
.append(this.addressName, rhs.getAddressName())
.isEquals();
}

public int hashCode() {
return new HashCodeBuilder(17, 37).
append(addressName).
toHashCode();
}

}
mapping 文件

<class name="Person" table="person">
<id name="id" type="long" column="id">
<generator class="native"/>
</id>
<property name="username" column="username" type="string"/>
<one-to-one
name="address"
class="Address"
cascade="all"
constrained="false"
/>
</class>

<class name="Address" table="Address" >
<id name="id" column="id">
<generator class="foreign">
<param name="property">person</param>
</generator>
</id>
<one-to-one name="person" class="Person" constrained="true"/>
<property name="addressName" column="addressName" type="string"/>
</class>

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