是否有助手知道属性是否已被Hibernate加载？ [英] Is there a helper to know whether a property has been loaded by Hibernate?

问题描述

我需要一个助手来知道一个属性是否已经被加载，以避免 LazyInitializationException 。

I need a helper to know whether a property has been loaded as a way to avoid LazyInitializationException. Is it possible?

@Entity
public class Parent {
    @OneToMany
    private List<Child> childList;
}

@Entity
public class Child {

}

"select distinct p from Parent p left join fetch p.childList";

// Answer goes here
// I want to avoid LazyInitializationException
SomeHelper.isLoaded(p.getChildList());

推荐答案

实际上有两种方法。

为了找出懒惰的属性是否已经初始化，您可以调用 Hibernate.isPropertyInitialized（）

To find out whether a lazy property has been initialized you can invoke Hibernate.isPropertyInitialized() method with your entity instance and property name as parameters.

若要确定是否有一个懒惰的集合（或实体）已经初始化（就像你的例子），你可以调用 Hibernate.isInitialized（） ，集合（实体）实例作为参数。

To find out whether a lazy collection (or entity) has been initialized (like in your example) you can invoke Hibernate.isInitialized() with collection (entity) instance as parameter.

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