Spring Data

Question 1

What is Spring ORM and Spring Data?

Answer 1

-Spring ORM:Object Relational Mapper
Module designed to integrate data access code into a spring app
-Spring Data: project by SpringSource with the intent to unify and ease the access to different kinds of persistent storage for both SQL, and nonSQL databases

Question 2

What is the Template design pattern and what is the JDBC template?

Answer 2

-Template design pattern is a pattern that encapsulates and supports similar algorithms to perform different kinds of business requirements by abstracting classes and allowing subclasses to determine concrete behavior.
-JDBCTemplate is a class that allows an object oriented way of executing queries to databases

Question 3

What does @Transactional do? What is the PlatformTransactionManager?

Answer 3

-We put @Transactional over our DAO methods, indicates that the methods should execute in a transactional context.
-Central interface in Spring’s transaction infrastructure, apps can use directly but is not meant to be an API

Question 4

What is a PersistenceContext?

Answer 4

It handles a set of entities which are stored in a persistent store such as a database. The context is aware of different states of an entity within the context and the store itself.

Question 5

Explain how to integrate Spring and Hibernate using ContextualSession

Answer 5

-You can use JPA annotation in bean classes to map beans to tables
-Implement DAO classes
-Use SessionFactory in DAO implementations to perform transactions
-Use beans xml to integrate beans with spring

Question 6

What interfaces are available in Spring Data JPA?

Answer 6

Repository
CrudRepository
PagingAndSortingRepository
JPARrepository

Question 7

What is the difference between JPARepository and CrudRepository?

Answer 7

JPARepository extends PagingAndSortingRepository which extends CrudRepository and provides JPA related methods.

Question 8

What is the naming conventions for methods in Spring Data repositories?

Answer 8

Follow Java naming conventions, an underscore _ can be used inside method name to manually define traversal points.

Question 9

How are Spring repositories implemented by Spring at runtime?

Answer 9

Uses SpringData REST to create an implementation of the repository interface automatically

Question 10

What is @Query used for?

Answer 10

Used to define SQL to execute, allows us to execute SQL queries in an object oriented manner.