Entity inheritance mapping in Hibernate can easily be done by following one of the three strategies and many a times instance of which subclass has to be created is identified by the value of the discriminator column (particularly in the case of table per class hierarchy). For such mappings there is already an inherent support in Hibernate.
So this is good if we want to create a sub class of a specific type for each row but what about if we want to create an instance of a specific class for a value of a column within that row. So in a way some type of component inheritance mapping. This is required if I really do not want to convert a value object (component) into an entity as that might mean sacrifice on the part of good model design as I am loosing the distinction between a component and an entity.
A workaround for the moment could be to somehow use a UserType to create instance of such objects based upon the value stored in the column. The concept of discriminator column can still help us. Let’s see how by taking up the following example
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