{"id":12434,"date":"2024-08-24T10:00:48","date_gmt":"2024-08-24T04:30:48","guid":{"rendered":"https:\/\/www.placementpreparation.io\/blog\/?p=12434"},"modified":"2025-02-27T12:59:32","modified_gmt":"2025-02-27T07:29:32","slug":"spring-boot-interview-questions-for-freshers","status":"publish","type":"post","link":"https:\/\/www.placementpreparation.io\/blog\/spring-boot-interview-questions-for-freshers\/","title":{"rendered":"Top Spring Boot Interview Questions for Freshers"},"content":{"rendered":"

Are you preparing for your first Spring Boot interview and wondering what questions you might face?<\/p>

Understanding the key Spring Boot interview questions for freshers can give you more clarity.<\/p>

With this guide, you’ll be well-prepared to tackle these Spring Boot interview questions and answers for freshers and make a strong impression in your interview.<\/p>

\"fsd<\/a><\/p>

Practice Spring Boot Interview Questions and Answers<\/h2>

Below are the top 50 Spring Boot interview questions for freshers with answers:<\/p>

1. How do you create a basic Spring Boot application using the @SpringBootApplication annotation?<\/h3>

Answer:<\/strong><\/p>

Use the @SpringBootApplication<\/strong> annotation to mark the main class, which serves as the entry point for the Spring Boot application.<\/p>

\n

@SpringBootApplication
\npublic class MyApp {
\npublic static void main(String[] args) {
\nSpringApplication.run(MyApp.class, args);
\n}
\n}<\/p>\n<\/div><\/div>

2. How do you configure an embedded server’s port in a Spring Boot application?<\/h3>

Answer:<\/strong><\/p>

You can set the server port using the application.properties<\/strong> or application.yml<\/strong> file.<\/p>

\n

server.port=8081<\/p>\n<\/div><\/div>

3. Write a Spring Boot application that reads a custom configuration property and prints it.<\/h3>

Answer:<\/strong><\/p>

Use @Value<\/strong> to inject the custom property and print it in a @PostConstruct<\/strong> method.<\/p>

\n

@Value(“${my.custom.property}”)
\nprivate String customProperty;<\/p>\n

@PostConstruct
\npublic void printProperty() {
\nSystem.out.println(customProperty);
\n}<\/p>\n<\/div><\/div>

4. How do you handle application startup tasks in Spring Boot?<\/h3>

Answer:<\/strong><\/p>

Implement the CommandLineRunner<\/strong> interface to execute code after the application context is loaded.<\/p>

\n

@Bean
\npublic CommandLineRunner run() {
\nreturn args -> System.out.println(“Application started”);
\n}<\/p>\n<\/div><\/div>

5. How do you create a simple REST controller in Spring Boot?<\/h3>

Answer:<\/strong><\/p>

Use @RestController<\/strong> and @RequestMapping<\/strong> to define endpoints that return JSON responses.<\/p>

\n

@RestController
\n@RequestMapping(“\/api”)
\npublic class MyController {
\n@GetMapping(“\/hello”)
\npublic String sayHello() {
\nreturn “Hello, World!”;
\n}
\n}<\/p>\n<\/div><\/div>

6. How do you define and use multiple profiles in a Spring Boot application?<\/h3>

Answer:<\/strong><\/p>

Use the @Profile<\/strong> annotation to activate different beans based on the active profile.<\/p>

\n

@Bean
\n@Profile(“dev”)
\npublic MyService devService() {
\nreturn new MyService(“Development Service”);
\n}<\/p>\n<\/div><\/div>

7. How do you load different configuration files for different environments in Spring Boot?<\/h3>

Answer:<\/strong><\/p>

Use profile-specific configuration files like application-dev.properties<\/strong> and application-prod.properties<\/strong>.<\/p>

\n

# application-dev.properties
\nmy.custom.property=devValue<\/p>\n

# application-prod.properties
\nmy.custom.property=prodValue<\/p>\n<\/div><\/div>

8. How do you externalize application properties in Spring Boot using environment variables?<\/h3>

Answer:<\/strong><\/p>

Set the environment variable and reference it in the application.properties<\/strong> file.<\/p>

\n

my.custom.property=${MY_ENV_VARIABLE}<\/p>\n<\/div><\/div>

9. Write a Spring Boot application that conditionally loads a bean based on a property value.<\/h3>

Answer:<\/strong><\/p>

Use the @ConditionalOnProperty<\/strong> annotation to conditionally load beans.<\/p>

\n

@Bean
\n@ConditionalOnProperty(name = “feature.enabled”, havingValue = “true”)
\npublic MyService featureService() {
\nreturn new MyService(“Feature Service”);
\n}<\/p>\n<\/div><\/div>

10. How do you configure a Spring Boot application to log different levels for different packages?<\/h3>

Answer:<\/strong><\/p>

Configure logging levels in the application.properties<\/strong> file for specific packages.<\/p>

\n

logging.level.com.example=DEBUG
\nlogging.level.org.springframework=WARN<\/p>\n<\/div><\/div>

11. How do you handle a POST request in a Spring Boot REST controller to create a new resource?<\/h3>

Answer:<\/strong><\/p>

Use @PostMapping<\/strong> to handle POST requests and @RequestBody<\/strong> to bind the request payload to an object.<\/p>

\n

@PostMapping(“\/users”)
\npublic User createUser(@RequestBody User user) {
\nreturn userService.save(user);
\n}<\/p>\n<\/div><\/div>

12. Write a Spring Boot controller method that returns a list of resources in JSON format.<\/h3>

Answer:<\/strong><\/p>

Use @GetMapping<\/strong> to define the endpoint and return a list of resources.<\/p>

\n

@GetMapping(“\/users”)
\npublic List<User> getAllUsers() {
\nreturn userService.findAll();
\n}<\/p>\n<\/div><\/div>

13. How do you handle path variables in Spring Boot REST endpoints?<\/h3>

Answer:<\/strong><\/p>

Use @PathVariable<\/strong> to extract values from the URI path.<\/p>

\n

@GetMapping(“\/users\/{id}”)
\npublic User getUserById(@PathVariable Long id) {
\nreturn userService.findById(id);
\n}<\/p>\n<\/div><\/div>

14. How do you implement exception handling for RESTful services in Spring Boot?<\/h3>

Answer:<\/strong><\/p>

Use @ControllerAdvice<\/strong> and @ExceptionHandler<\/strong> to handle exceptions globally.<\/p>

\n

@ControllerAdvice
\npublic class GlobalExceptionHandler {
\n@ExceptionHandler(UserNotFoundException.class)
\npublic ResponseEntity<String> handleUserNotFound(UserNotFoundException ex) {
\nreturn new ResponseEntity<>(ex.getMessage(), HttpStatus.NOT_FOUND);
\n}
\n}<\/p>\n<\/div><\/div>

15. Write a Spring Boot application that validates a request body using @Valid.<\/h3>

Answer:<\/strong><\/p>

Use @Valid<\/strong> in the controller method and annotate the fields in the request object.<\/p>

\n

@PostMapping(“\/users”)
\npublic User createUser(@Valid @RequestBody User user) {
\nreturn userService.save(user);
\n}<\/p>\n<\/div><\/div>

16. How do you secure a Spring Boot REST API using basic authentication?<\/h3>

Answer:<\/strong><\/p>

Use HttpSecurity in the WebSecurityConfigurerAdapter<\/strong> to configure basic authentication.<\/p>

\n

@Override
\nprotected void configure(HttpSecurity http) throws Exception {
\nhttp.authorizeRequests()
\n.anyRequest().authenticated()
\n.and().httpBasic();
\n}<\/p>\n<\/div><\/div>

17. How do you restrict access to certain endpoints in a Spring Boot application based on user roles?<\/h3>

Answer:<\/strong><\/p>

Use @PreAuthorize<\/strong> to restrict access based on roles.<\/p>

\n

@PreAuthorize(“hasRole(‘ADMIN’)”)
\n@GetMapping(“\/admin”)
\npublic String adminEndpoint() {
\nreturn “Admin access”;
\n}<\/p>\n<\/div><\/div>

18. Write a Spring Boot configuration that disables CSRF protection for a specific endpoint.<\/h3>

Answer:<\/strong><\/p>

Use csrf().disable()<\/strong> in the security configuration to disable CSRF protection.<\/p>

\n

@Override
\nprotected void configure(HttpSecurity http) throws Exception {
\nhttp.csrf().disable()
\n.authorizeRequests()
\n.antMatchers(“\/public\/**”).permitAll()
\n.anyRequest().authenticated();
\n}<\/p>\n<\/div><\/div>

19. How do you implement JWT authentication in a Spring Boot application?<\/h3>

Answer:<\/strong><\/p>

Use a filter to validate JWT tokens and set the authentication in the security context.<\/p>

\n

public class JwtFilter extends OncePerRequestFilter {
\nprotected void doFilterInternal(HttpServletRequest req, HttpServletResponse res, FilterChain chain) {
\n\/\/ Extract and validate JWT
\n}
\n}<\/p>\n<\/div><\/div>

20. How do you customize the login form in a Spring Boot security configuration?<\/h3>

Answer:<\/strong><\/p>

Use formLogin()<\/strong> to customize the login page and success\/failure handlers.<\/p>

\n

@Override
\nprotected void configure(HttpSecurity http) throws Exception {
\nhttp.formLogin()
\n.loginPage(“\/login”)
\n.defaultSuccessURL(“\/home”)
\n.failureUrl(“\/login?error=true”);
\n}<\/p>\n<\/div><\/div>

21. Write a Spring Boot repository method to find all users with a specific role using JPA.<\/h3>

Answer:<\/strong><\/p>

Define a query method in the repository interface to fetch users by role.<\/p>

\n

List<User> findByRole(String role);<\/p>\n<\/div><\/div>

22. How do you implement pagination in a Spring Boot REST API using Spring Data JPA?<\/h3>

Answer:<\/strong><\/p>

Use Pageable<\/strong> in the repository method and pass it to the service layer.<\/p>

\n

Page<User> findAll(Pageable pageable);<\/p>\n<\/div><\/div>

23. How do you execute a native SQL query in Spring Boot using JPA?<\/h3>

Answer:<\/strong><\/p>

Use the @Query<\/strong> annotation with nativeQuery<\/strong> set to true<\/strong>.<\/p>

\n

@Query(value = “SELECT * FROM users WHERE email = ?1”, nativeQuery = true)
\nUser findByEmail(String email);<\/p>\n<\/div><\/div>

24. Write a Spring Boot service method that updates a user’s details in the database.<\/h3>

Answer:<\/strong><\/p>

Use the repository’s save()<\/strong> method to update the user details.<\/p>

\n

public User updateUser(User user) {
\nreturn userRepository.save(user);
\n}<\/p>\n<\/div><\/div>

25. How do you handle transactions in a Spring Boot application using @Transactional?<\/h3>

Answer:<\/strong><\/p>

Annotate the service method with @Transactional<\/strong> to manage transactions.<\/p>

\n

@Transactional
\npublic void transferMoney(Long fromAccountId, Long toAccountId, BigDecimal amount) {
\n\/\/ Transfer logic
\n}<\/p>\n<\/div><\/div>

26. How do you write a unit test for a Spring Boot service class using Mockito?<\/h3>

Answer:<\/strong><\/p>

Use @MockBean<\/strong> to mock dependencies and verify service behavior.<\/p>

\n

@MockBean
\nprivate UserRepository userRepository;<\/p>\n

@Test
\npublic void testFindUserById() {
\nwhen(userRepository.findById(1L)).thenReturn(Optional.of(new User(“John”)));
\nassertEquals(“John”, userService.findUserById(1L).getName());
\n}<\/p>\n<\/div><\/div>

27. Write an integration test for a Spring Boot REST controller using @SpringBootTest.<\/h3>

Answer:<\/strong><\/p>

Use @SpringBootTest<\/strong> and TestRestTemplate<\/strong> to perform integration tests.<\/p>

\n

@Test
\npublic void testGetUser() {
\nResponseEntity<User> response = restTemplate.getForEntity(“\/api\/users\/1”, User.class);
\nassertEquals(HttpStatus.OK, response.getStatusCode());
\nassertEquals(“John”, response.getBody().getName());
\n}<\/p>\n<\/div><\/div>

28. How do you test a Spring Boot application with an in-memory database?<\/h3>

Answer:<\/strong><\/p>

Use H2 in-memory database and configure it in application.properties<\/strong>.<\/p>

\n

spring.datasource.url=jdbc:h2:mem:testdb<\/p>\n<\/div><\/div>

29. Write a Spring Boot test that verifies the loading of the application context.<\/h3>

Answer:<\/strong><\/p>

Use @SpringBootTest<\/strong> with a simple test method to check context loading.<\/p>

@SpringBootTest
\npublic class ApplicationContextTest {
\n@Test
\nvoid contextLoads() {
\n}
\n}<\/p>

\n[\/su_note]\n<\/p>

30. How do you test a Spring Boot service method that involves a transaction?<\/h3>

Answer:<\/strong><\/p>

Use @Transactional<\/strong> in the test class and verify the transaction behavior.<\/p>

\n

@Test
\n@Transactional
\npublic void testTransactionalMethod() {
\nuserService.updateUser(user);
\nassertEquals(“UpdatedName”, userRepository.findById(user.getId()).get().getName());
\n}<\/p>\n<\/div><\/div>

31. How do you send a message to a Kafka topic in a Spring Boot application?<\/h3>

Answer:<\/strong><\/p>

Use the KafkaTemplate<\/strong> to send messages to a Kafka topic.<\/p>

\n

@Autowired
\nprivate KafkaTemplate<String, String> kafkaTemplate;<\/p>\n

public void sendMessage(String topic, String message) {
\nkafkaTemplate.send(topic, message);
\n}<\/p>\n<\/div><\/div>

32. Write a Spring Boot application that consumes messages from a RabbitMQ queue.<\/h3>

Answer:<\/strong><\/p>

Use @RabbitListener<\/strong> to consume messages from the specified queue.<\/p>

\n

@RabbitListener(queues = “myQueue”)
\npublic void receiveMessage(String message) {
\nSystem.out.println(“Received: ” + message);
\n}<\/p>\n<\/div><\/div>

33. How do you configure a JMS queue in a Spring Boot application?<\/h3>

Answer:<\/strong><\/p>

Use @JmsListener<\/strong> to listen to a JMS queue and configure the connection factory.<\/p>

\n

@JmsListener(destination = “myQueue”)
\npublic void receiveMessage(String message) {
\nSystem.out.println(“Received: ” + message);
\n}<\/p>\n<\/div><\/div>

34. Write a Spring Boot method that sends an email using JavaMailSender.<\/h3>

Answer:<\/strong><\/p>

Use JavaMailSender<\/strong> to compose and send an email.<\/p>

\n

@Autowired
\nprivate JavaMailSender mailSender;<\/p>\n

public void sendEmail(String to, String subject, String text) {
\nSimpleMailMessage message = new SimpleMailMessage();
\nmessage.setTo(to);
\nmessage.setSubject(subject);
\nmessage.setText(text);
\nmailSender.send(message);
\n}<\/p>\n<\/div><\/div>

35. How do you configure a REST endpoint in Spring Boot to asynchronously process a request?<\/h3>

Answer:<\/strong><\/p>

Use @Async<\/strong> in the service method to process requests asynchronously.<\/p>

\n

@Async
\npublic CompletableFuture<String> asyncMethod() {
\nreturn CompletableFuture.completedFuture(“Hello, Async”);
\n}<\/p>\n<\/div><\/div>

36. How do you expose custom metrics in a Spring Boot application using Actuator?<\/h3>

Answer:<\/strong><\/p>

Use @Component<\/strong> and @Timed<\/strong> annotations to expose custom metrics.<\/p>

\n

@Timed(value = “custom.metric.time”, description = “Time taken to execute method”)
\npublic String customMethod() {
\nreturn “Custom Metric”;
\n}<\/p>\n<\/div><\/div>

37. Write a Spring Boot actuator endpoint that provides custom health check information.<\/h3>

Answer:<\/strong><\/p>

Implement HealthIndicator<\/strong> to create a custom health check endpoint.<\/p>

\n

@Component
\npublic class CustomHealthIndicator implements HealthIndicator {
\n@Override
\npublic Health health() {
\nreturn Health.up().withDetail(“Custom”, “Available”).build();
\n}
\n}<\/p>\n<\/div><\/div>

38. How do you customize the Spring Boot Actuator endpoints to change their default path?<\/h3>

Answer:<\/strong><\/p>

Use management.endpoints.web.base-path<\/strong> in application.properties<\/strong>.<\/p>

\n

management.endpoints.web.base-path=\/manage<\/p>\n<\/div><\/div>

39. Write a Spring Boot application that uses Actuator to monitor HTTP request metrics.<\/h3>

Answer:<\/strong><\/p>

Include the micrometer-core<\/strong> dependency and expose HTTP request metrics using @Timed<\/strong>.<\/p>

\n

@Timed(value = “http.requests”, description = “HTTP Request Metrics”)
\n@GetMapping(“\/metrics”)
\npublic String metrics() {
\nreturn “Metrics”;
\n}<\/p>\n<\/div><\/div>

40. How do you secure Spring Boot Actuator endpoints?<\/h3>

Answer:<\/strong><\/p>

Configure security settings in application.properties<\/strong> or application.yml<\/strong> to restrict access.<\/p>

\n

management.endpoints.web.exposure.include=health,info
\nmanagement.endpoint.health.roles=ADMIN<\/p>\n<\/div><\/div>

41. How do you implement service discovery in a Spring Boot microservice using Netflix Eureka?<\/h3>

Answer:<\/strong><\/p>

Annotate the main class with @EnableEurekaClient<\/strong> and configure Eureka in application.properties<\/strong>.<\/p>

\n

eureka.client.serviceUrl.defaultZone=http:\/\/localhost:8761\/eureka\/<\/p>\n<\/div><\/div>

42. Write a Spring Boot application that acts as a Netflix Zuul API Gateway.<\/h3>

Answer:<\/strong><\/p>

Use @EnableZuulProxy<\/strong> in the main class to create an API Gateway.<\/p>

\n

@EnableZuulProxy
\n@SpringBootApplication
\npublic class ApiGatewayApplication {
\npublic static void main(String[] args) {
\nSpringApplication.run(ApiGatewayApplication.class, args);
\n}
\n}<\/p>\n<\/div><\/div>

43. How do you implement client-side load balancing in a Spring Boot application using Ribbon?<\/h3>

Answer:<\/strong><\/p>

Use @LoadBalanced<\/strong> annotation with RestTemplate<\/strong> to enable Ribbon for load balancing.<\/p>

\n

@Bean
\n@LoadBalanced
\npublic RestTemplate restTemplate() {
\nreturn new RestTemplate();
\n}<\/p>\n<\/div><\/div>

44. Write a Spring Boot application that implements circuit breaking using Netflix Hystrix.<\/h3>

Answer:<\/strong><\/p>

Use @HystrixCommand<\/strong> to define fallback methods for circuit-breaking.<\/p>

\n

@HystrixCommand(fallbackMethod = “fallback”)
\npublic String callExternalService() {
\nreturn restTemplate.getForObject(“http:\/\/external-service\/api”, String.class);
\n}<\/p>\n

public String fallback() {
\nreturn “Fallback response”;
\n}<\/p>\n<\/div><\/div>

45. How do you configure distributed tracing in a Spring Boot microservice using Spring Cloud Sleuth?<\/h3>

Answer:<\/strong><\/p>

Add spring-cloud-starter-sleuth<\/strong> dependency and configure Sleuth in application.properties<\/strong>.<\/p>

\n

spring.sleuth.sampler.probability=1.0<\/p>\n<\/div><\/div>

46. How do you enable Spring Boot DevTools for automatic application restart?<\/h3>

Answer:<\/strong><\/p>

Include the spring-boot-devtools<\/strong> dependency in the pom.xml<\/strong> or build.gradle<\/strong> file.<\/p>

\n

<dependency>
\n<groupId>org.springframework.boot<\/groupId>
\n<artifactId>spring-boot-devtools<\/artifactId>
\n<\/dependency><\/p>\n<\/div><\/div>

47. Write a Spring Boot configuration that disables DevTools in production.<\/h3>

Answer:<\/strong><\/p>

Use the spring.devtools.restart.enabled<\/strong> property to disable DevTools in production.<\/p>

\n

spring.devtools.restart.enabled=false<\/p>\n<\/div><\/div>

48. How do you configure LiveReload in a Spring Boot application using DevTools?<\/h3>

Answer:<\/strong><\/p>

Enable LiveReload in application.properties<\/strong>.<\/p>

\n

spring.devtools.livereload.enabled=true<\/p>\n<\/div><\/div>

49. Write a Spring Boot method that uses @ConfigurationProperties to map application properties to a POJO.<\/h3>

Answer:<\/strong><\/p>

Create a POJO and annotate it with @ConfigurationProperties<\/strong> to bind properties.<\/p>

\n

@ConfigurationProperties(prefix = “app”)
\npublic class AppProperties {
\nprivate String name;
\nprivate String version;
\n\/\/ Getters and setters
\n}<\/p>\n<\/div><\/div>

50. How do you configure conditional beans in Spring Boot based on DevTools being active?<\/h3>

Answer:<\/strong><\/p>

Use @ConditionalOnProperty<\/strong> to conditionally create beans based on DevTools properties.<\/p>

\n

@Bean
\n@ConditionalOnProperty(name = “spring.devtools.restart.enabled”, havingValue = “true”)
\npublic MyService devToolsService() {
\nreturn new MyService();
\n}<\/p>\n<\/div><\/div>

Final Words<\/h2>

Getting ready for an interview can feel overwhelming, but going through these Spring Boot fresher interview questions can help you feel more confident.<\/p>

With the right preparation, you’ll ace your Spring Boot interview but don’t forget to practice the Spring Boot basic coding interview questions too!<\/p>

Frequently Asked Questions<\/h2>

1. What are the most common interview questions for Spring Boot?<\/h3>

Common interview questions for Spring Boot typically focus on creating REST APIs, configuring Spring Boot applications, dependency injection, and working with databases using Spring Data JPA.<\/p>

2. What are the important Spring Boot topics freshers should focus on for interviews?<\/h3>

Freshers should focus on understanding the basics of Spring Boot, RESTful web services, dependency injection, Spring Data JPA, and security configurations.<\/p>

3. How should freshers prepare for Spring Boot technical interviews?<\/h3>

Freshers should practice building small Spring Boot projects, understand the core annotations, and familiarize themselves with key concepts like auto-configuration and Spring Boot starters.<\/p>

4. What strategies can freshers use to solve Spring Boot coding questions during interviews?<\/h3>

Freshers should approach coding questions by clearly understanding the problem, breaking down the requirements, and using Spring Boot’s annotations and configurations effectively.<\/p>

5. Should freshers prepare for advanced Spring Boot topics in interviews?<\/h3>

Yes, depending on the role, it’s beneficial to have a basic understanding of advanced topics like microservices, Spring Cloud, and security configurations.<\/p>

Explore More Spring Boot Resources<\/h2>