休眠:永远不会调用 MyInterceptor#onFlushDirty [英] Hibernate: MyInterceptor#onFlushDirty is never called

问题描述

问题: 为什么 MyInterceptor#onFlushDirty 永远不会被调用?

Question: Why MyInterceptor#onFlushDirty is never called?

我在像

<bean id="myEntityManagerFactory" parent="abstractEntityManagerFactoryBean" abstract="true">
  <property name="entityInterceptor">
    <bean class="xxxx.MyInterceptor"/>
  </property>
</bean>
<bean id="abstractEntityManagerFactoryBean" class="xxxx.MyEntityManagerFactoryBean"/>

MyEntityManagerFactoryBean

public class MyEntityManagerFactoryBean extends AbstractEntityManagerFactoryBean implements LoadTimeWeaverAware {
  private Interceptor entityInterceptor;

  public Interceptor getEntityInterceptor() {
    return entityInterceptor;
  }

  public void setEntityInterceptor(Interceptor interceptor) {
    entityInterceptor = interceptor;
  }
}

我的拦截器:

public class MyInterceptor extends EmptyInterceptor {

    public MyInterceptor() {
        System.out.println("init"); // Works well 
    }
    // PROBLEM - is never called
    @Override
    public boolean onFlushDirty(Object entity,
                                Serializable id,
                                Object[] currentState,
                                Object[] previousState,
                                String[] propertyNames,
                                Type[] types) {

        if (entity instanceof File) {
            .....
        }
        return false;
    }
}

<小时>

更新:[解释为什么自定义脏策略看起来不像我的方式]

每次我更改 Folder 实体中的某些内容时，我都希望更新 modified 时间戳，除了 folderPosition.同时folderPosition 应该是持久的而不是短暂的(意味着导致实体变脏).

I want update modified timestamp each time I change something in Folder entity EXCEPT folderPosition. In the same time folderPosition should be persistent and not transient (means cause entity to be dirty).

由于我使用 Spring Transactional 和 Hibernate 模板，所以有一些细微差别:

Due I use Spring Transactional and Hibernate Templates, there is some nuances:

1) 我无法在每个 setter 的末尾更新修改后的时间戳，例如:

1) I can't update modified timestamp at the end of each setter like:

public void setXXX(XXX xxx) {
  //PROBLEM: Hibernate templates collect object via setters, 
  //means simple get query will cause multiple 'modified' timestamp updates
  this.xxx = xxx;
  this.modified = new Date();
}

2) 我不能手动调用 setModified，因为它有大约 25 个字段，并且每个字段的 setXXX 分散在整个应用程序中.而且我没有能力进行重构.

2) I can't call setModified manually, because it has about 25 fields, and setXXX for each field is scattered across whole app. And I have no power to make refactoring.

@Entity
public class Folder {

  /**
   * GOAL: Changing of each of these fields except 'folderPosition' should cause 
   * 'modified' timestamp update
   */
  private long id;
  private String name;
  private Date created;
  private Date modified;
  private Integer folderLocation;

  @PreUpdate
  public void preUpdate() {
     //PROBLEM : change modified even if only location field has been changed!
     //PROBLEM: need to know which fields have been updated!
     modified = new Date(); 
  }   
  ....
}

推荐答案

您需要扩展 findDirty 方法而不是 onFlushDirty.检查本教程的详细说明，并参考了一个 GitHub 工作示例.

You need to extend the findDirty method not onFlushDirty. Check this tutorial for a detail explanation with a reference to a GitHub working example.

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