Learn what is Persistent Fields and Properties in Entity ClassesLearn what is Persistent Fields and Properties in Entity Classes
In this tutorial we will understand about the Persistent Fields and Properties in Entity Classes. Here we will learn about the field types supported in the JPA.
As explained in the earlier sections the Entity is managed by the EntityManager and it provides the API's for accessing the entities. You can load an entity and then access its state through variables or properties. In JPA fields and properties must confirms to the types as described in the JPA specification.
Following Java Language types of fields and properties are supported:
The JPA specification allows the entities to use persistent fields, persistent properties, or a combination of both. You can use the mapping annotations to properly specify the meta-data to the JPA runtime. The Java style getters and setters methods are used to access the properties/entities.
Finding Entities Using the EntityManager
You can find an entity using the the find method of EntityManager. Here is an example:
Product prodObj = em.find(Product.class,2);