基于外键的方式：
附上代码：
public class Manager { ???private Integer mgrId; ???private String mgrName; ???private Department department; ???public Integer getMgrId() { ???????return mgrId; ???} ???public void setMgrId(Integer mgrId) { ???????this.mgrId = mgrId; ???} ???public String getMgrName() { ???????return mgrName; ???} ???public void setMgrName(String mgrName) { ???????this.mgrName = mgrName; ???} ???public Department getDepartment() { ???????return department; ???} ???public void setDepartment(Department department) { ???????this.department = department; ???}}public class Department { ???private Integer deptId; ???private String deptName; ???private Manager manager; ???public Integer getDeptId() { ???????return deptId; ???} ???public void setDeptId(Integer deptId) { ???????this.deptId = deptId; ???} ???public String getDeptName() { ???????return deptName; ???} ???public void setDeptName(String deptName) { ???????this.deptName = deptName; ???} ???public Manager getManager() { ???????return manager; ???} ???public void setManager(Manager manager) { ???????this.manager = manager; ???}}<hibernate-mapping> ???<class name="hibernate.one2one.foreign.Department" table="DEPARTMENTS"> ???????<id name="deptId" type="java.lang.Integer"> ???????????<column name="DEPT_ID" /> ???????????<generator class="native" /> ???????</id> ???????<property name="deptName" type="java.lang.String"> ???????????<column name="DEPT_NAME" /> ???????</property> ???????<many-to-one name="manager" class="hibernate.one2one.foreign.Manager" unique="true" fetch="join"> ???????????<column name="MGR_ID"></column> ???????</many-to-one> ???</class></hibernate-mapping>
<hibernate-mapping> ???<class name="hibernate.one2one.foreign.Manager" table="MANAGER"> ???????<id name="mgrId" type="java.lang.Integer"> ???????????<column name="MGR_ID" /> ???????????<generator class="native" /> ???????</id> ???????<property name="mgrName" type="java.lang.String"> ???????????<column name="MGR_NAME" /> ???????</property> ???????<one-to-one name="department" ???????????class="hibernate.one2one.foreign.Department" ???????????fetch="select" ???????????property-ref="manager"> ???????????????</one-to-one> ???</class></hibernate-mapping>
其中 Department 使用 many-to-one 的方式映射 Manager，但是需要设置一个 unique 属性，设置为 true，使其只能指向一个 Manager
Manager 使用 one-to-one 的方式来映射 Department，注意需要设置一个 property-ref 属性，因为其默认关联的是 Department 表中的主键，需要设置其指向 Department 哪个属性，注意，这里设置的值是域对象中的值，不是数据表中的列名。
Hibernate 映射一对一关联关系
原文地址：http://www.cnblogs.com/zyx1301691180/p/7701301.html