声明的元模型属性工作正常,但继承的元模型属性为空。为什么?

我无法运行以下测试:-

@Test
public void test() {
    EntityManager em = entityManagerFactory.createEntityManager();
    em.getTransaction().begin();

    CriteriaBuilder builder = em.getCriteriaBuilder();
    CriteriaQuery<Project> query = builder.createQuery(Project.class);

    Root<Project> project = query.from(Project.class);

    Path<String> name = project.get(Project_.name);
    Assert.assertNotNull(name);

    Path<EntityLifeCycleImpl> lifeCycle = project.get(Project_.lifeCycle); // problem is here, throws NullPointer
    Assert.assertNotNull(lifeCycle);
}

project.get(Project_.lifeCycle) 行。为什么?

java.lang.NullPointerException
    at org.hibernate.ejb.criteria.path.AbstractPathImpl.get(AbstractPathImpl.java:138)

PersistenceEntityBase.java

import org.hibernate.annotations.GenericGenerator;
        @MappedSuperclass
@Access(AccessType.PROPERTY)
public abstract class PersistentEntityBase {

protected String identifier;

protected EntityLifeCycleImpl lifeCycle = new EntityLifeCycleImpl();

protected PersistentEntityBase() {
}

@Id
@GeneratedValue(generator="generator") 
@GenericGenerator(name="generator", strategy="guid", parameters = {})
@Column(name="identifier")
public String getIdentifier() {
    return identifier;
}

public void setIdentifier(String identifier) {
    this.identifier = identifier;
}

@Embedded
public EntityLifeCycleImpl getLifeCycle() {
    return lifeCycle;
}
public void setLifeCycle(EntityLifeCycleImpl lifeCycle) {
    this.lifeCycle = lifeCycle;
}

}

项目.java

@Entity
@Table(name="project")
@Access(AccessType.PROPERTY)
public class Project extends PersistentEntityBase {

    private String name;

    protected Project() {
    }

    public Project(String name) {
        this();
        this.name = name;
    }

    @Column(name="name", nullable=false, unique=true)
    public String getName() {
        return name;
}
public void setName(String name) {
    this.name = name;
}

实体生命周期impl.java

@Embeddable
public class EntityLifeCycleImpl implements EntityLifeCycle {
    private String createdBy;
    private Date createdDate;
       @Column(name="created_by")
public String getCreatedBy() {
    return createdBy;
}
public void setCreatedBy(String createdBy) {

    this.createdBy = createdBy;
}

@Column(name="created_date")
public Date getCreatedDate() {
    return createdDate;
}
public void setCreatedDate(Date createdDate) {
    this.createdDate = createdDate;
}

}

持久实体库java

   @StaticMetamodel(PersistentEntityBase.class)
public abstract class PersistentEntityBase_ {
    public static volatile SingularAttribute<PersistentEntityBase, EntityLifeCycleImpl> lifeCycle;
        public static volatile SingularAttribute<PersistentEntityBase, String> identifier;
     }

java项目

    @StaticMetamodel(Project.class)
public abstract class Project_ extends PersistentEntityBase_ {
    public static volatile SingularAttribute<Project, String> name;
    }

java实体生命周期

   @StaticMetamodel(EntityLifeCycleImpl.class)
public abstract class EntityLifeCycleImpl_ {
    public static volatile SingularAttribute<EntityLifeCycleImpl, String> createdBy;
    public static volatile SingularAttribute<EntityLifeCycleImpl, Date> createdDate;
}

持久性.xml

<class>com.comp.timetracking.entity.PersistentEntityBase</class>
<class>com.comp.timetracking.entity.Project</class>

编辑: 我使用hibernate-entitymanager.3.6.0.Final和hibernate-jpamodelgen.1.0.0.Final。

编辑2
我认为Hibernate EM 3.6.0.Final允许我们定义 @Embedded 注释字段位于 @Entity 但它否认 @MappedSuperclass

因为我在这里看不到“文件上传选项”,所以我已经在我的esnips帐户中上传了测试用例。 Download 基于maven的项目和运行 SingularAttributeTest.java

ERROR main metamodel.MetadataContext:413 - Unable to locate static metamodel field : timetracking.entity.Employee_#lifeCycle

点击“ 下载embedded-singular-attribute.zip “链接可在不安装下载管理器的情况下下载文件。(如果您单击 Download link with Green arrow ,您必须安装下载管理器!!)