HibernateException：实例的标识符已从 Alert@62794582 更改为 Alert@c82ad22

Question

我正在使用 Hibernate JPA 实现持久性 API。
我正在使用 PostgreSQL 10.4 并将数据存储为 JSONB。
我正在分享我对 Hibernate 和 Entity 的实现，请指出为什么我会遇到异常。

我关注这篇精彩的文章来实现自定义 UserType，因为 Hibernate 不支持 PostgreSQL JSONB 数据类型：
https://www.thoughts-on-java.org/persist-postgresqls-jsonb-data-type-hibernate/

我能够创建实体映射并执行简单的 Select 查询并打印分配给映射的值。

问题是当我对事务执行提交操作时，出现以下异常：

22:42:35.218 [main] DEBUG org.hibernate.engine.transaction.internal.TransactionImpl - rollback() called on an inactive transaction Exception in thread "main" javax.persistence.RollbackException: Error while committing the transaction at org.hibernate.jpa.internal.TransactionImpl.commit(TransactionImpl.java:86) at com.postgres.main.TestMain.main(TestMain.java:41) Caused by: javax.persistence.PersistenceException: org.hibernate.HibernateException: identifier of an instance of com.postgres.model.Alert was altered from com.postgres.model.Alert@62794582 to com.postgres.model.Alert@c82ad22 at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1692) at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1602) at org.hibernate.jpa.internal.TransactionImpl.commit(TransactionImpl.java:67) ... 1 more Caused by: org.hibernate.HibernateException: identifier of an instance of com.postgres.model.Alert was altered from com.postgres.model.Alert@62794582 to com.postgres.model.Alert@c82ad22 at org.hibernate.event.internal.DefaultFlushEntityEventListener.checkId(DefaultFlushEntityEventListener.java:64) at org.hibernate.event.internal.DefaultFlushEntityEventListener.getValues(DefaultFlushEntityEventListener.java:175) at org.hibernate.event.internal.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:135) at org.hibernate.event.internal.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:216) at org.hibernate.event.internal.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:85) at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:38) at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1295) at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:468) at org.hibernate.internal.SessionImpl.flushBeforeTransactionCompletion(SessionImpl.java:3135) at org.hibernate.internal.SessionImpl.beforeTransactionCompletion(SessionImpl.java:2352) at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.beforeTransactionCompletion(JdbcCoordinatorImpl.java:485) at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.beforeCompletionCallback(JdbcResourceLocalTransactionCoordinatorImpl.java:147) at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.access0(JdbcResourceLocalTransactionCoordinatorImpl.java:38) at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.commit(JdbcResourceLocalTransactionCoordinatorImpl.java:231) at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:65) at org.hibernate.jpa.internal.TransactionImpl.commit(TransactionImpl.java:61) ... 1 more

我也关注了 post 那里的人们分享了他们如何解决这个问题，但这对我没有帮助：
Hibernate: How to fix "identifier of an instance altered from X to Y"?

这是警报实体：

@Entity
@IdClass(Alert.class)
@Table(name = "alert")
public class Alert implements Serializable
{
    private static final long serialVersionUID = 1L;

    @Id
    @Column(name = "historyid")
    private Character historyId;

    @Id
    @Column(name = "tenantname")
    private Character tenantName;

    @Column(name = "data")
    @Type(type = "AlertJsonUserType")
    private AlertJson alertJson;

    public Character getHistoryId() {
        return historyId;
    }

    public void setHistoryId(Character historyId) {
        this.historyId = historyId;
    }

    public Character getTenantName() {
        return tenantName;
    }

    public void setTenantName(Character tenantName) {
        this.tenantName = tenantName;
    }

    public AlertJson getAlertJson() {
        return alertJson;
    }

    public void setAlertJson(AlertJson alertJson) {
        this.alertJson = alertJson;
    }
}

这是警报实体中 JSONB 元素的实体

public class AlertJson implements Serializable 
{
    private static final long serialVersionUID = 1L;

    @JsonProperty("DeviceId")
    private String deviceId;

    @JsonProperty("TenantName")
    private String tenantName;

    @JsonProperty("FocusPointId")
    private List<FocusPointId> focusPointId;

    public String getDeviceId() {
        return deviceId;
    }

    public void setDeviceId(String deviceId) {
        this.deviceId = deviceId;
    }

    public String getTenantName() {
        return tenantName;
    }

    public void setTenantName(String tenantName) {
        this.tenantName = tenantName;
    }

    public List<FocusPointId> getFocusPointId() {
        return focusPointId;
    }

    public void setFocusPointId(List<FocusPointId> focusPointId) {
        this.focusPointId = focusPointId;
    }
}

class FocusPointId
{
    @JsonProperty("PartNumber")
    private String partNumber;

    @JsonProperty("SerialNumber")
    private String serialNumber;

    public String getPartNumber() {
        return partNumber;
    }

    public void setPartNumber(String partNumber) {
        this.partNumber = partNumber;
    }

    public String getSerialNumber() {
        return serialNumber;
    }

    public void setSerialNumber(String serialNumber) {
        this.serialNumber = serialNumber;
    }
  }

下面是 main() 的片段，我在其中创建 EntityManager 实例并发出查询

public static void main(String[] args)
{
    EntityManagerFactory emf = Persistence.createEntityManagerFactory("my-persistence-unit");

    EntityManager em = emf.createEntityManager();
    em.getTransaction().begin();

    Query alertQuery = em.createNativeQuery("SELECT * FROM \"A.01\".\"Alert\" where tenantname = 'TestUser-152'", Alert.class);
    List<Alert> alertList = alertQuery.getResultList();

    for(Alert jsonElement : alertList)
    {
        System.out.println("======> "+"Device: " + jsonElement.getAlertJson().getDeviceId() + " TenantName: " +jsonElement.getAlertJson().getTenantName());
    }

    em.getTransaction().commit();

    emf.close();
}

下面是描述 table 和约束。 PK既是historyid又是tenantname。

Answer 1

我认为你有这个问题是因为你错误地使用了 IdClass 注释，你应该创建一个单独的 class AlertId 例如，它必须包含来自你的组合 PK 的字段，并且此 class 应用作 IdClass 注释

的参数

HibernateException：实例的标识符已从 Alert@62794582 更改为 Alert@c82ad22

HibernateException: identifier of an instance was altered from Alert@62794582 to Alert@c82ad22

postgresql

hibernate

jpa

jsonb

usertype