Question

是我无法摆脱的例外。

我有一个实体：

package mypackage.entities;

import javax.persistence.Entity;
import javax.persistence.Table;

@Entity
@Table(name = "raw_air_pressure")
public class RawAirPressureData extends RawSensorData {

    @Override
    public String toString() {
        [...]
    }
}

具有其超类：

package mypackage.entities;

import javax.persistence.Column;
import javax.persistence.MappedSuperclass;
import javax.validation.constraints.NotNull;

@MappedSuperclass
public abstract class RawSensorData extends BaseSensorData {

    @Column(name = "timestamp")
    @NotNull
    private Long timestamp;

    public Long getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(Long timestamp) {
        this.timestamp = timestamp;
    }

    @Override
    public int hashCode() {
        [...]
    }

    @Override
    public boolean equals(Object obj) {
        [...]
    }
}

具有其超类：

package mypackage.entities;

import java.util.Date;

import javax.persistence.Column;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.MappedSuperclass;
import javax.persistence.SequenceGenerator;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import javax.validation.constraints.NotNull;

import org.hibernate.annotations.CreationTimestamp;
import org.hibernate.annotations.UpdateTimestamp;

@MappedSuperclass
public abstract class BaseSensorData {

    @Id
    @SequenceGenerator(name = "my_seq", sequenceName = "my_seq", allocationSize = 1)
    @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="my_seq")
    @Column(name = "id")
    private Integer id;

    @Column(name = "value")
    @NotNull
    private Float value;

    @CreationTimestamp
    @Column(name = "created")
    @Temporal(TemporalType.TIMESTAMP)
    private Date created;

    @UpdateTimestamp
    @Column(name = "updated")
    @Temporal(TemporalType.TIMESTAMP)
    private Date updated;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public Float getValue() {
        return value;
    }

    public void setValue(Float value) {
        this.value = value;
    }

    public Date getCreated() {
        return created;
    }

    public void setCreated(Date created) {
        if(created != null) {
            this.created = created;
        }
    }

    public Date getUpdated() {
        return updated;
    }

    public void setUpdated(Date updated) {
        if(updated != null) {
            this.updated = updated;
        }
    }

    @Override
    public int hashCode() {
        [...]
    }

    @Override
    public boolean equals(Object obj) {
        [...]
    }   
}

该实体已注册为休眠状态（dropwizard样式）：

private static final HibernateBundle<MyServerConfiguration> hibernate = new HibernateBundle<MyServerConfiguration>(
    MyEntity1.class, MyEntity2.class, [...],
    RawAirPressureData.class) {

@Override
    public DataSourceFactory getDataSourceFactory(MyServerConfiguration configuration) {
        return configuration.getDataSourceFactory();
    }
};

执行此JUnit时：

@Test
    public void testRawAirPressureData() {
        RawAirPressureData myData = TestUtils.generateTestRawAirPressureData();

        RawAirPressureData testMyData = database.inTransaction(() -> {
            return rawAirPressureDataDAO.persist(myData );
        });
[...]

我收到此异常：

org.hibernate.MappingException：未知实体： mypackage.entities.RawAirPressureData位于 org.hibernate.metamodel.internal.MetamodelImpl.entityPersister（MetamodelImpl.java:620）在 org.hibernate.internal.SessionImpl.getEntityPersister（SessionImpl.java:1635）在 org.hibernate.engine.internal.ForeignKeys.isTransient（ForeignKeys.java:225）在 org.hibernate.event.internal.AbstractSaveEventListener.getEntityState（AbstractSaveEventListener.java:499）在 org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.performSaveOrUpdate（DefaultSaveOrUpdateEventListener.java:83）在 org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate（DefaultSaveOrUpdateEventListener.java:73）在 org.hibernate.internal.SessionImpl.fireSaveOrUpdate（SessionImpl.java:660）在 org.hibernate.internal.SessionImpl.saveOrUpdate（SessionImpl.java:652）在 org.hibernate.internal.SessionImpl.saveOrUpdate（SessionImpl.java:647）在io.dropwizard.hibernate.AbstractDAO.persist（AbstractDAO.java:202）在 mypackage.db.BaseSensorDataDAO.persist（BaseSensorDataDAO.java:33）在 mypackage.db.BaseSensorDataDAOTest.lambda $ testRawAirPressureData $ 6（BaseSensorDataDAOTest.java:196）

所有先前的实体都可以正常工作。但是它们都不是由mappingsuperclass组成的。我不明白这里出了什么问题。

任何帮助将不胜感激。

Answer 1

问题在于，尽管将使用序列，但在单元测试中，数据集是通过给出ID来创建的。因此，它似乎首先使用给定的ID存储记录，然后尝试按导致optimisitcLockException的顺序覆盖它。

在删除测试数据中的ID集之后，该序列就可以自由运行了。

@MappedSuperClass和Dropwizard的休眠未知实体异常

1 个答案: