Java, Hibernate annotations, How to add methods to POJO object?

Question

I am using hibernate annotations. How to add methods to POJO object? For example i have "getChildNodes" method, associated with database, but i want also add recursive method "getAllChildNodes". I get "org.hibernate.PropertyNotFoundException: Could not find a setter for property progress in class" exception when i do it.

Answer 1

Open up the .java file and write a method named getAllChildNodes().

Hibernate doesn't write code for you, it maps fields in your database to your code. That's all. If you want to have extra logic in your domain/model classes besides the normal getters and setters for your properties, you'll have to add them yourself.

Answer 2

If I interpret this as "how do I add a method that is NOT related to persistence" then you need to use the @Transient annotation on the getAllChildNodes() method

Answer 3

There are two ways of defining the structure of your entity.

• using annotations on the instance variables of your entity or
• using annotations on the getter methods of your entity

When using the annotations on getter methods, Hibernate assumes that every getXxx (and isXxx for boolean types) represents definition of a persistent property. And this holds even if that particular getter does not contain any annotations, as happens in your case.

Hibernate also expects to find a matching setter method for each persistent property. And in your case that is what's missing and causes the exception.

You can solve this problem by declaring your custom getter as @Transient that says this getter does not represent a persistent property. Another way would be to convert the entity to use annotations on the instance variables. The latter would be my personal choice.