3. Spring Boot Flashcards
What is Spring Boot?
Spring Boot is an open-source Java-based framework used to create stand-alone, production-grade Spring-based applications. It simplifies the setup and development of new Spring applications.
What are the main features of Spring Boot?
The main features of Spring Boot include auto-configuration, standalone applications, production-ready features, microservices support, and a wide range of starter dependencies.
True or False: Spring Boot requires extensive XML configuration.
False. Spring Boot aims to minimize the need for XML configuration by using annotations and convention over configuration.
Fill in the blank: Spring Boot applications can be run as ______.
standalone Java applications.
What is the purpose of the @SpringBootApplication annotation?
@SpringBootApplication is a convenience annotation that combines @Configuration, @EnableAutoConfiguration, and @ComponentScan, enabling easier configuration of a Spring Boot application.
How does Spring Boot handle dependency management?
Spring Boot uses a dependency management feature that allows developers to easily manage dependencies and their versions via the Spring Boot Starter POMs.
What is a Spring Boot Starter?
A Spring Boot Starter is a set of convenient dependency descriptors that can be included in an application. They simplify the process of adding various features to the application.
What is the default port for a Spring Boot application?
The default port for a Spring Boot application is 8080.
What is the Spring Boot Actuator?
Spring Boot Actuator provides production-ready features such as monitoring and management capabilities for Spring Boot applications, including metrics, health checks, and application information.
What is the purpose of the application.properties file in Spring Boot?
The application.properties file is used to configure various properties of a Spring Boot application, such as server port, database configurations, logging levels, and more.
True or False: Spring Boot can be used to create RESTful web services.
True. Spring Boot is commonly used to create RESTful web services and APIs.
What is the role of the Spring Initializr?
Spring Initializr is a web-based tool that helps developers quickly generate a Spring Boot project structure with the necessary dependencies and configurations.
Explain the concept of auto-configuration in Spring Boot.
Auto-configuration is a feature in Spring Boot that automatically configures your application based on the dependencies present in the classpath. It reduces the need for manual configuration.
What is a Bean in Spring Boot?
A Bean is an object that is instantiated, assembled, and managed by the Spring IoC container. Beans are the backbone of a Spring application.
What is the difference between @Component, @Service, and @Repository annotations?
@Component is a generic stereotype for any Spring-managed component. @Service is a specialization of @Component for service layer components, and @Repository is a specialization for data access layer components.
What does the @RestController annotation do?
@RestController is a convenience annotation that combines @Controller and @ResponseBody, indicating that the methods in the class will return data instead of views.
What is Spring Boot DevTools?
Spring Boot DevTools provides additional development-time features such as automatic restarts, live reload, and configurations for improved development experience.
How can you create a Spring Boot application?
You can create a Spring Boot application using Spring Initializr, by selecting dependencies, generating the project, and then importing it into your IDE.
What is the purpose of the @Configuration annotation?
@Configuration is used to indicate that a class contains Spring configuration. It can define beans and their dependencies.
What is the Spring Boot CLI?
The Spring Boot CLI (Command Line Interface) is a tool that allows you to run and test Spring Boot applications from the command line using Groovy scripts.
What is the significance of the @Value annotation?
@Value is used to inject values into fields from property files or environment variables, allowing for externalized configuration of Spring applications.
What is Spring Data JPA?
Spring Data JPA is a part of the Spring Data project that simplifies data access and manipulation using Java Persistence API (JPA) and provides a repository abstraction.
Explain the concept of profiles in Spring Boot.
Profiles in Spring Boot allow you to segregate parts of your application configuration and make it only available in certain environments, such as development, testing, and production.
What is the purpose of the @Autowired annotation?
@Autowired is used for automatic dependency injection, allowing Spring to resolve and inject collaborating beans into your bean.
What is the Spring Boot testing framework?
Spring Boot comes with a comprehensive testing framework that supports unit and integration testing, providing annotations like @SpringBootTest, @MockBean, and @DataJpaTest.
What does the @Entity annotation do?
@Entity is used to indicate that a class is a JPA entity and should be mapped to a database table.
What is the purpose of the @Transactional annotation?
@Transactional is used to define the scope of a database transaction and ensures that all operations within that scope are executed within a single transaction.
What is Spring Security?
Spring Security is a powerful and customizable authentication and access control framework for Java applications that integrates seamlessly with Spring Boot.
How can you customize error handling in a Spring Boot application?
You can customize error handling in Spring Boot by implementing the ErrorController interface, using @ControllerAdvice for global exception handling, or defining custom error pages.
What is the difference between @RequestMapping and @GetMapping?
@RequestMapping is a versatile annotation for mapping HTTP requests to handler methods, while @GetMapping is a shortcut for @RequestMapping with the GET request method.
What is a Spring Boot Microservice?
A Spring Boot Microservice is an independently deployable application built using Spring Boot that follows the microservices architecture, allowing for scalability and flexibility.
What is Spring Cloud?
Spring Cloud is a suite of tools designed to help developers build distributed systems and microservices, providing features like configuration management, service discovery, and circuit breakers.
What is the role of a Spring Boot application context?
The application context is the central interface to the Spring IoC container, responsible for instantiating, configuring, and managing the lifecycle of application beans.
What does the term ‘Convention over Configuration’ mean in Spring Boot?
Convention over Configuration means that Spring Boot provides sensible defaults and configurations, allowing developers to focus on business logic rather than boilerplate code.
What is the purpose of the CommandLineRunner interface?
The CommandLineRunner interface is used to execute code after the Spring application has started, allowing for initialization or setup tasks.
What is Spring Boot’s logging framework?
Spring Boot uses Apache Commons Logging for internal logging but allows the use of various logging frameworks such as Logback, Log4j2, and Java Util Logging.
How do you create a REST API using Spring Boot?
To create a REST API using Spring Boot, define a controller class with @RestController, create request mapping methods using @GetMapping, @PostMapping, etc., and return data in a JSON format.
What is the purpose of the @PathVariable annotation?
@PathVariable is used to extract values from the URI template and bind them to method parameters in a controller.
What is a Spring Boot starter project for web applications?
The Spring Boot Starter Web project is a dependency that includes all the necessary components to develop web applications, including Spring MVC and embedded Tomcat.
Explain how to handle exceptions globally in Spring Boot.
You can handle exceptions globally in Spring Boot using @ControllerAdvice along with @ExceptionHandler methods to define how specific exceptions should be handled.
What is the significance of the @ComponentScan annotation?
@ComponentScan is used to specify the base packages to scan for Spring-managed components and beans.
What is the purpose of the @Scheduled annotation?
@Scheduled is used to execute a method at a specified interval or at a fixed time, enabling scheduled tasks in a Spring Boot application.
What is the purpose of the @EnableScheduling annotation?
@EnableScheduling is used to enable support for scheduled tasks in Spring Boot, allowing methods annotated with @Scheduled to be executed at specified intervals.
What is Spring Boot’s approach to external configuration?
Spring Boot allows for external configuration through property files, YAML files, environment variables, and command-line arguments, promoting flexibility in application setup.
What is a Spring Boot profile?
A Spring Boot profile is a way to group configuration settings to be used in specific environments, allowing for different configurations for development, testing, and production.
What is the role of the Spring Boot banner?
The Spring Boot banner is a customizable ASCII art that is displayed in the console when the application starts, allowing developers to personalize the startup experience.
True or False: Spring Boot applications can be packaged as JAR or WAR files.
True. Spring Boot applications can be packaged as executable JAR or traditional WAR files for deployment.
What is Spring Boot’s support for database migrations?
Spring Boot supports database migrations through tools like Flyway and Liquibase, allowing for version control of database schemas.
What is the purpose of the @EnableAutoConfiguration annotation?
@EnableAutoConfiguration is used to enable Spring Boot’s auto-configuration feature, allowing Spring to automatically configure beans based on the dependencies present.
What is the Spring Boot Test module?
The Spring Boot Test module provides utilities and annotations for testing Spring Boot applications, including support for context loading and dependency injection.
How do you configure a data source in Spring Boot?
You can configure a data source in Spring Boot by adding the required database dependencies in the pom.xml or build.gradle file and specifying the connection properties in application.properties or application.yml.
What is Spring Boot’s approach to security?
Spring Boot provides built-in security features through Spring Security, allowing for easy configuration of authentication, authorization, and security measures in applications.
What is the purpose of the @RequestBody annotation?
@RequestBody is used to bind the HTTP request body to a Java object in a controller method, allowing for easy deserialization of JSON or XML data.
How can you enable CORS in a Spring Boot application?
You can enable CORS in a Spring Boot application by using the @CrossOrigin annotation on controller methods or by configuring a global CORS mapping in the WebMvcConfigurer.
What is the role of the DispatcherServlet in Spring Boot?
The DispatcherServlet is the front controller in Spring MVC that handles incoming requests, dispatches them to the appropriate handlers, and manages the response.
What is the purpose of the @ResponseStatus annotation?
@ResponseStatus is used to mark a method or exception class with a specific HTTP status code, allowing for customized response status in a web application.
What is Spring Boot’s default logging framework?
The default logging framework used by Spring Boot is Logback, but it allows switching to other logging frameworks if desired.
What is the significance of the @Conditional annotation?
@Conditional is used to conditionally enable or disable a bean based on the evaluation of a specified condition, allowing for more dynamic bean configuration.
What is a Spring Boot starter for security?
The Spring Boot Starter Security is a dependency that includes Spring Security and its default configurations, simplifying the setup of security features in a Spring Boot application.
How do you access application properties in a Spring Boot application?
You can access application properties in a Spring Boot application using the @Value annotation or by binding them to a configuration properties class using @ConfigurationProperties.
What is the purpose of the @EnableWebMvc annotation?
@EnableWebMvc is used to enable Spring MVC features in a Spring application, allowing for the configuration of MVC components.
What is the role of Spring Boot’s embedded servers?
Spring Boot’s embedded servers, such as Tomcat, Jetty, or Undertow, allow applications to be run as standalone applications without requiring an external server setup.
What is the purpose of the @RequestParam annotation?
@RequestParam is used to extract query parameters from the request URL and bind them to method parameters in a controller.
What is Spring Boot’s approach to internationalization (i18n)?
Spring Boot supports internationalization through message source configurations, allowing applications to serve different languages and locales based on user preferences.
What is a Spring Boot actuator endpoint?
Spring Boot actuator endpoints are built-in endpoints that expose operational information about the application, such as health, metrics, and environment properties.
How do you create a custom actuator endpoint in Spring Boot?
You can create a custom actuator endpoint in Spring Boot by defining a new controller class and annotating it with @Endpoint, and then implementing the desired methods.
What is the purpose of the @Cacheable annotation?
@Cacheable is used to indicate that the result of a method call should be cached, improving performance for frequently called methods.
What is the role of the @Scheduled annotation in Spring Boot?
@Scheduled is used to schedule tasks to be executed at fixed intervals or specific times, enabling background processing in Spring Boot applications.
What is Spring Boot’s approach to web security?
Spring Boot provides web security configurations through Spring Security, allowing developers to secure web applications with authentication and authorization mechanisms.
What is the significance of the @EnableAsync annotation?
@EnableAsync is used to enable asynchronous method execution in a Spring Boot application, allowing methods annotated with @Async to run in a separate thread.
How do you implement pagination in a Spring Boot application?
You can implement pagination in a Spring Boot application using Spring Data JPA’s Pageable and Page classes, allowing for easy retrieval of paginated data.
What is the purpose of the @Transactional annotation at the class level?
@Transactional at the class level applies transaction management to all public methods within that class, ensuring atomicity for all operations.
How do you handle file uploads in a Spring Boot application?
You can handle file uploads in a Spring Boot application using the MultipartFile interface, allowing you to receive uploaded files in controller methods.
What is the role of Spring Boot’s configuration properties?
Spring Boot’s configuration properties allow for externalization of application configuration, enabling different settings for different environments.
What is the purpose of the @ResponseBody annotation?
@ResponseBody indicates that the return value of a method should be written directly to the HTTP response body, typically in JSON or XML format.
How do you implement exception handling in a Spring Boot REST API?
You can implement exception handling in a Spring Boot REST API using @ControllerAdvice and @ExceptionHandler to catch and handle exceptions globally.
What is the significance of the @CrossOrigin annotation?
@CrossOrigin is used to enable Cross-Origin Resource Sharing (CORS) for specific controllers or methods, allowing resources to be requested from different domains.
What is the purpose of the @JsonProperty annotation?
@JsonProperty is used to specify the logical name of a property when serializing or deserializing JSON data, allowing for custom mapping between JSON and Java fields.
What is the role of the @ConfigurationProperties annotation?
@ConfigurationProperties is used to bind external configuration properties to a Java class, allowing for structured access to configuration settings.
How can you secure a REST API in Spring Boot?
You can secure a REST API in Spring Boot by configuring Spring Security to enforce authentication, authorization, and access control on the API endpoints.
