A particular instance of an entity class can be loaded as follows:
Foo foo = fooRepository.findOne(id);
findOne method is provided by the
CrudRepository interface. It expects an identifier that uniquely identifies an entity instance (for instance, a primary key in a database table). The Java type for the
id parameter must match the type assigned to the entity attribute annotated with the JPA
findOne method results in the JPA query
select foo from Foo foo where foo.[primary-key-column] = :id being executed on the underlying database.