Is it possible to dynamically trigger calling of the @PostLoad method only on demand

Env: JBoss Seam, JPA, Hibernate

We use the @PostLoad annotation to dynamically initializ开发者_开发技巧e some of the transient variables in our @Entity (sometimes this involves looking up the parent entity to initialize status - which is a costly operation).

But under certain circumstances, we don't want this @PostLoad to get triggered, since we will not rely on the transient variables.

Is there a way to control the data dynamically post load.

One way to solve this issue, is to call this method only on demand (i.e. by removing the @PostLoad annotation and manually calling this method), but this is also error prone.

Are there any other ways to resolve this issue.

But under certain circumstances, we don't want this @PostLoad to get triggered, since we will not rely on the transient variables.

Create two entities, one with the @PostLoad and the transient fields, and one "lighter" without.

Haven't dealt with this in java but came across similar thing in kotlin + maven + spring project.

Understanding how @PostLoad works?

@PostLoad is called after fetching data using entity manager methods find() or refresh() operations is triggered to the database.

Scenario when it fails to trigger @PostLoad :

Suppose, a parent entity had this @transient variable which is initialised using a @PostLoad method. And also, you had a child entity which had mapping to this parent entity.

When you retrieve a child the find will load and persistence context is generated. Down the line when you tried to access parent content then another find is triggered. But this won't trigger the @PostLoad method of parent because the operation is triggered from the existing context.

Which would generally throw the uninitialized errors.

Solution

In the above scenario, I don't really need multiple entities. As I knew this behaviour. I would create an entity class method for parent to dynamically load the contents for the respective transient variable or even set some defaults for a special scenario. And trigger or manage this method in the converter methods or where-ever the use case is.