Hibernate inheritance mapping unknown property

I am struggling with my inheritance structure where I have a mapped superclass which contains a common field in the concrete classes. This superclass has a one-to-one mapping with a "wrapper" object.

The objects look like this;

@Entity
public class Wrapper {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "wrapper_id", nullable = false)
    private Long wrapperId;

    @OneToOne(fetch = FetchType.LAZY, mappedBy = "wrapper")
    @Cascade(CascadeType.SAVE_UPDATE)
    private Base base;

    public Long getWrapperId() {
        return wrapperId;
    }

    public void setWrapperId(Long wrapperId) {
        this.wrapperId = wrapperId;
    }

    public Base getBase() {
        return base;
    }

    public void setBase(Base base) {
        this.base = base;
    }

}

@MappedSuperclass
@Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
public class Base {

    @OneToOne(fetch = FetchType.LAZY)
    @Cascade(CascadeType.SAVE_UPDATE)
    @JoinColumn(name = "wrapper_id")
    protected Wrapper wrapper;

    public Wrapper getWrapper() {
        return wrapper;
    }

    public void setWrapper(Wrapper wrapper) {
        this.wrapper = wrapper;
    }

}

@Entity
public class SubA extends Base {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "sub_a_id", nullable = false)
    private Long subAId;

    public Long getSubAId() {
        return subAId;
    }

    public void setSubAId(Long subAId) {
        this.subAId = subAId;
    }

}

For simplicity I have only included a single concrete class but I have several.

This mapping works great when I do not have a reference to "Base" in the wrapper object. As soon as I try to add the bi-directional relationship between the wrapper and base I start to get this error....which doesn't make sense as the field is there.

Caused by: org.hibernate.AnnotationException: Unknown mappedBy in: com.xxx.Wrapper.base, referenced property unknown: com.xxx.Base.wrapper
    at org.hibernate.cfg.OneToOneSecondPass.doSecondPass(OneToOneSecondPass.java:153)
    at org.hibernate.cfg.Configuration.originalSecondPassCompile(Configuration.java:1697)
    at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1426)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1846)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1930)
    at org.springframework.orm.hibernate4.LocalSessionFactoryBuilder.buildSessionFactory(LocalSessionFactoryBuilder.java:372)
    at org.springframework.orm.hibernate4.LocalSessionFactoryBean.buildSessionFactory(LocalSessionFactoryBean.java:453)
    at org.springframework.orm.hibernate4.LocalSessionFactoryBean.afterPropertiesSet(LocalSessionFactoryBean.java:438)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1627)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1564)
    ... 50 more

What am I missing? Thanks,

We ended up doing a lot of prototyping with the different options (mapped super class, hierarchical etc) and weighed the options.

In the end we decided to create object hierarchies coupled with the @Entity annotation, Inheritance strategy of SINGLE_TABLE and using Discriminator values to give us exactly what we needed without sacrificing too much.

Thank you all for your suggestions.