Spring Boot

Question 1

What are the 3 annotations that make up @SpringBootApplication?

Answer 1

1. @SpringBootConfiguration
2. @ComponentScan
3. @EnableAutoConfiguration

Question 2

Which annotation can you use to scan for components defined outside of the main package?

Answer 2

@SpringBootApplication(scanBasePackages=String[])

Question 3

What are the 2 steps necessary to load profile-specific application.properties?

Answer 3

1. @Profile(profileName)
2. application-[profileName].properties

Question 4

What are the 4 ways to disable auto-configuration?

Answer 4

1. Define your own beans
2. application.properties
3. spring.autoconfigure.exclude=[package]
4. @SpringBootApplication(exclude=Class[])

Question 5

True or False

Spring related properties should be defined in application.properties and non-spring related properties should be defined elsewhere

Answer 5

True

Question 6

What does SpringApplication.run() return?

Answer 6

ConfigurableApplicationContext which is a subtype of ApplicationContext

Question 7

How can you change the logging level of a Spring Boot application?

Answer 7

logging.level.[package]=?

INFO is the default logging level

Question 8

Does Spring Boot autoconfigure a datasource if an embedded database is used?

Answer 8

Yes. For example, when HSQLDB is used, Spring boot will autoconfigure a datasource

Question 9

What is Spring Boot’s property source order?

Answer 9

link

Question 10

Is application.properties loaded before other property files?

Answer 10

Yes

Question 11

What is the command to build a Spring Boot executable with Maven?

Answer 11

./mvnw package

Question 12

Which file will always load?

1. application-local.properties
2. application-cloud.properties
3. application.properties

Answer 12

application.properties

Question 13

What is the syntax for adding command line properties to a Spring Boot application?

Answer 13

--key=value

Question 14

True or False

If you define a set of configuration keys for your own components, we recommend you group them in a POJO annotated with @ConfigurationProperties

Answer 14

True

Question 15

True or False

spring.profiles.include overrides existing properties when used

Answer 15

False

Question 16

True or False

When Jackson is on the classpath an ObjectMapper bean is automatically configured

Answer 16

True

Question 17

True or False

Unlike a nested @Configuration class, which would be used instead of your application’s primary configuration, a nested @TestConfiguration class is used in addition to your application’s primary configuration.

Answer 17

True

Question 18

True or False

Regardless of your classpath, meter registries, except the in-memory backed, are not auto-configured when using @SpringBootTest.

If you need to export metrics to a different backend as part of an integration test, annotate it with @AutoConfigureObservability

Answer 18

True

Question 19

True or False

It is possible to include multiple slices in a test class

Answer 19

False

Question 20

True or False

Make sure to not use the regular @Import annotation to import auto-configurations as they are handled in a specific way by Spring Boot

Answer 20

True

Use @ImportAutoConfiguration instead

Question 21

Since your @SpringBootApplication class is used by default as the configuration for your tests, it is important not to litter the application’s main class with configuration settings that are specific to a particular area of its functionality

For example:

@SpringBootApplication
@EnableMongoAuditing
public class MyApplication {

    // ...

}

Answer 21

True

@EnableMongoAuditing should be moved to its own configuration class