Continue to work on the Maven project started as exercise in the first lesson.
In the pom.xml file, add the following dependency:
javax:javaee-api
Create a Stateless EJB called CategoryEjb.
Such class should be in a different folder/package from where you
chose to have your @Entity classes.
Inject a EntityManager into the EJB, and then write the following methods:
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Long createCategory(String name)Create and persist a category with a given name. Return the id of newly created entity.
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Long createSubCategory(long parentId, String name)Create and persist a subcategory with a given name and belonging to the specified category. Return the id of newly created entity.
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List<Category> getAllCategories(boolean withSub)Return all the existing categories. The boolean input specifies whether the subcategories should be forced-loaded as well inside that method.
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Category getCategory(long id, boolean withSub)Return the category specified by id. The boolean input specifies whether the subcategories should be forced-loaded as well inside that method.
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SubCategory getSubCategory(long id)Return the subcategory specified by id.
Solutions to this exercise can be found in the
intro/exercise-solutions/quiz-game/part-04 module.