Spring Boot-301

Question 1

What is spring.provides

Answer 1

Each starter has a spring .provides file, which tells by using this starter package what we will get it : spring-test, spring-boot, spring-junit…

Question 2

What is the nomenclature for starter pack?

Answer 2

spring-boot-starter-[…](web, data,

Question 3

What is a CommandLineRunner

Answer 3

scan all components and invokes

Question 4

How can we the Order of invokation of beans?

Answer 4

@Order or implement and Ordered IF

Question 5

Is there a IN to extends in corresponding to each @Spring Annotation

Answer 5

Yes , extend it and customize

Question 6

Does Boot creates the DataSource automatically?

Answer 6

Yes the Boot will create DS for H2, Derby , HSQL, just have to add one in CP

Question 7

Show the class of SpringBootApplication ?

Answer 7

@Configuration
@EnableAutoConfiguration
@ComponentScan
public Interface SpringBootApplication {
}

Question 8

Is SpringBootApplication an IF

Answer 8

Yes

Question 9

What @Configuration does?

Answer 9

It says that @BEan, @ComponentScan & @Service

Question 10

What @ComponentScan does?

Answer 10

It says that to scan all base packages for Spring annotaions. THe base package is the package the SpringBootApplication belongs to

Question 11

What @EnableAutoConfiguratioon?

Answer 11

It composes of EnableAutoConfigurationalImmortSelecrtor

& ConfigurationPackages.Registrar to automatically configure the conditional beans

Question 12

What does SpringApplication.run does?

Answer 12

It creates a Spring application context, that reads the annotations of class in parenthesis and instantiates

Question 13

IS CommandLineInterface is and IF?

Answer 13

Yes

Question 14

Which method CommandLineInterface has>?

Answer 14

Just one method public void run(String… args)

Question 15

What is the relevance of run in CommandLineInterface

Answer 15

it just called once when SpringBoots

Question 16

Which class is we have for DataOperations?

Answer 16

DataSource

Question 17

Are there DB predefined properties for DS?

Answer 17

Yes in app.prop spring.datasource.url, spring.datasource.username, spring.datasource.password
and the like

Question 18

IS it possible to configure DS external to Boot App, like JBoss, tomcat and the like ?

Answer 18

YEs by using spring.datasource.jndi-name

Question 19

Can we use - in app.props ?

Answer 19

Yes and they get transalated to camel case

Question 20

Can we configure the hibernate props also in app.props?

Answer 20

Yes, like spring.jpa.hibernate.ddl-auto=create-drop

Question 21

Is DS can be wrapped onve JDBCTemplate?

Answer 21

Yes,
Use
@Autowired
private JdbcTemplate jdbcTemplate;

Question 22

Which class is for DS?

Answer 22

org. springframework.boot.autoconfig-

ure. jdbc.DataSourceAutoConfiguration

Question 23

How can we create a repository?

Answer 23

By extending CrudRepository

Question 24

Name some annotations of Java persistence api?

Answer 24

@Entity, @Id, @GeneratedValue, @OneToMany, @ManyToOne, @ManyToMany

Question 25

Why it is important to have a protected constructor in an @Entityclass?

Answer 25

it is needed for automatic instantiation and hibernate interactions

Question 26

what is the relevance of @Entity?

Answer 26

It is meant to map the entity class to table object

Question 27

what is the relevance of @Repository?

Answer 27

This IF is intended to provide them with the access and manipulation of data for a database

Question 28

what is the relevance of CrudRepository?

Answer 28

It gives the basic CRUD operations on a table object