50+ [REAL-TIME] Spring MVC Interview Questions and Answers

Spring MVC is a widely-used framework for building web applications in Java. It follows the Model-View-Controller architectural pattern, providing developers with a structured approach to develop scalable and maintainable web applications. With features like robust request handling, flexible configuration, and seamless integration with other Spring modules, Spring MVC simplifies the development process while promoting best practices.

1. What is MVC?

Ans:

The Model-View-Controller (MVC) pattern is an architectural design pattern for software that divides an application’s functionality into three interconnected parts: model, view, and controller. This approach makes it easier to reuse code and develop applications in parallel, and it is a widely used development approach. By separating concerns, MVC enhances maintainability and scalability, allowing developers to update components independently.

2. What is Spring MVC?

Ans:

Spring MVC is a Java framework for developing dynamic web applications. It implements all the basic features of a core spring framework, such as Dependency Injection and Inversion of Control. It adheres to the Model-View-Controller design pattern and architecture-specific format. Thus, view technologies such as JSP+JSTL, Apache Velocity, Thyme Leaf, and Free Marker can be used to generate a view page.

3. What is Spring MVC’s Front Controller?

Ans:

• The org. Spring framework. Web. The servlet package contains the Dispatcher Servlet class, the Front Controller. 
• It controls the application flow and forwards the request to the relevant Controller. 
• The web.xml file must contain the Dispatcher Servlet class specification.
• Additionally, the DispatcherServlet is responsible for initializing the Spring application context and configuring other components, such as view resolvers and handler mappings, ensuring a seamless integration of the MVC architecture.

4. What is the Spring MVC flow?

Ans:

• The Dispatcher Servlet, which functions as the front Controller, intercepts the request once it has been produced.
•  The request is sent to the Controller by the Dispatcher Servlet, which receives an entry of the handler mapping from the XML file. The Controller gives back an item of View And Model.
• The Coordinator The servlet invokes the designated view component once it has verified the view resolver item in the XML file.

5. What benefits does the Spring MVC Framework offer?

Ans:

• Different roles: The application is divided into three interconnected levels by Spring MVC, each with a specific role.
•  Lightweight: Use a lightweight servlet container to design and launch your application.
• Robust Configuration: It offers strong Configuration for application classes and the framework, facilitating simple cross-context referencing between web controllers, business objects, and validators.
• Quick development: Spring MVC makes working quickly and in parallel easier.

6. What is contained in an additional configuration file of a Spring MVC application?

Ans:

The properties data are in an extra configuration file with the Spring MVC application. This file may be generated as a properties file or as an XML file. Generally speaking, define the base package and view resolver in this file, which is where DispatcherServlet looks for the path of the view components and controller classes. It may also include several additional configuration attributes.

7. What is an Internal Resource View Resolver in Spring MVC?

Ans:

In Spring MVC, an internal view is resolved using a class called Internal Resource View Resolver. In this instance, you can specify the attributes such as prefix and suffix, where the view page’s location is contained in the prefix and its extension is contained in the suffix. As an illustration:- 

8. How does one declare a class in Spring MVC as a controller class?

Ans:

Use the Controller annotation to designate a class as a controller class. This annotation must be specified on the class name. 

As an illustration:

9. How may the controller class’s methods be mapped to a URL?

Ans:

• @RequestMapping: Maps a method to a specific URL pattern and supports all HTTP methods.
• @GetMapping: Specifically maps HTTP GET requests to a method, typically for retrieving data.
• @PostMapping: Maps HTTP POST requests to a method, commonly used for submitting data.
• @PutMapping and @DeleteMapping: Map HTTP PUT and DELETE requests, respectively, to handle updates and deletions of resources.

10. Explain the differences between Spring Boots and Spring.

Ans:

Aspect	Spring	Spring Boot
Purpose	Comprehensive framework for Java development	Simplifies creation of stand-alone, production-grade Spring-based applications
Configuration	Requires manual configuration	Emphasizes convention over configuration, offers auto-configuration and sensible defaults
Dependency Management	Manual dependency management	Simplifies dependency management with starter dependencies and auto-configuration
Embedded Servers	Needs external servlet containers (e.g., Tomcat, Jetty)	Comes with embedded servlet containers for standalone deployment

11. What does the PathVariable annotation mean in Spring MVC?

Ans:

The URI template’s value is extracted using the PathVariable annotation. It is transmitted within the handler method’s constraints.

As an illustration:

12. What function does the ResponseBody annotation serve?

Ans:

The returned object is automatically serialized in JSON and bound to the HTTP response body using the ResponseBody annotation. In this case, using the model is not necessary.

As an illustration:- 

13. How does Spring MVC use the Model interface?

Ans:

The Model interface functions as a container for the application’s data. Any type of data, including objects, texts, database information, etc., can be used in this context. The model in Spring MVC operates as a container holding the application’s data. The Model interface must be located in the application’s controller section. It enables the passing of data between the controller and the view, ensuring that the necessary information is available for rendering.

14. What does ModelAndView mean in Spring MVC?

Ans:

A class called ModelAndView contains both the Model and the View, where the View is a representation of the data, and the model is a representation of the data. This class returns the class returns the return value. Public class org.springframework.web.servlet. ModelAndView In the web MVC framework, ModelAndView extends Object—holder for both Model and View. Keep in mind that these are different. This class enables a controller to return the model and the View in a single return value.

15. What is ModelMap in Spring MVC?

Ans:

• HttpServletRequest interface: The javax.servlet.The HTTP package contains the HttpServletRequest interface. In Spring, HttpServletRequest allows you to read user-provided HTML form data, just like Servlets.
• RequestParam annotation: This annotation automatically links the form data to the parameter using the supplied method by reading the form data.
• ModelAttribute annotation links a named model attribute to a method parameter or its return value.

16. What is the purpose of ResponseBody?

Ans:

A controller is informed that the object returned is automatically serialized into JSON via the ResponseBody annotation and then returned to the HttpResponse object. When the ResponseBody annotation is used on a method, Spring automatically translates the return value and writes it to the HTTP response. This process eliminates the need for manual serialization, making it easier to build RESTful APIs. Additionally, it allows for seamless integration with various client-side technologies that consume JSON data.

17. What is the form tag library for Spring MVC?

Ans:

The form tags in Spring MVC are similar to data binding-aware tags in that they can automatically set and get data from Java objects and beans. These tags are a web page’s reusable and configurable building components. Spring MVC offers view technologies, which make it simple to create, access, and manage data. Additionally, these tags enhance developer productivity by reducing boilerplate code and streamlining the process of form handling.

18. What is meant by Spring MVC validations?

Ans:

One of the most significant components of Spring MVC is the validation, which limits the user’s input. The Bean Validation API and Spring 4 or later versions must be used to confirm the user’s input. Applications that are client-side or server-side can both be validated by Spring validations. Quickly validate user input data using the Spring MVC framework’s standard predefined validators. The widely used method for data validations in Spring applications is the Bean Validation API.

19. What is an API for Bean Validation?

Ans:

• A Java specification called the Bean Validation API limits object models using annotations. Here, validate a length, number, regular expression, etc., and offer personalized confirmations.
• Bean Validation API needs to be implemented because it is merely a specification. Therefore, the Hibernate Validator is used for that. The Hibernate Validator is an entirely compliant JSR-303/309 implementation that enables the expression and validation of application constraints.

20. Why is valid annotation used?

Ans:

The RequestBody annotation is used to indicate that the request body should be associated with the user parameter. The Valid annotation initiates the validation of the user object, instructing Spring to apply the validation criteria specified in the User class to the request body. This ensures that the data received meets the defined constraints, enhancing data integrity and application security. If any validation errors occur, Spring will respond with appropriate error messages, preventing invalid data from being processed.

21. What role does BindingResult serve in Spring MVC validations?

Ans:

• Error Management: BindingResult contains validation errors that arise during data binding, making it easy to access error messages.
• Binding Status: It provides details about the binding status, showing whether the binding was successful or if validation errors occurred.
• Conditional Processing: Enables developers to implement conditional logic in the controller based on the existence of errors, allowing for tailored error handling.

22. How can user input be verified to ensure a number is within a specified range in Spring MVC?

Ans:

User input in Spring MVC can be validated to ensure a number falls within a specified range by using validation annotations. The @Min and @Max annotations can be added to the relevant field in the Java model class, defining the minimum and maximum acceptable values. Upon form submission, Spring automatically checks the input against these constraints. If the input exceeds the specified range, a validation error occurs, allowing for appropriate feedback to be given to the user.

23. How can user input be verified in a specific order in Spring MVC?

Ans:

User input can be verified in a specific order in Spring MVC by utilizing validation groups. By creating different validation groups, constraints can be applied selectively according to the sequence of input processing. This enables sequential validation, where certain fields are checked first before others. The ‘@Validated’ annotation can be used alongside specific group classes to enforce this order. This method ensures that the validation logic is well-defined and aligned with the application’s workflow.

24. How does Spring MVC work?

Ans:

• Data Processing: Request is handled by the Controller
• Model Preparation: The Controller prepares to present the data model to the user.
• View Selection: The system selects a view template to display the model data.
• Rendering: Model data is loaded into the view template.
• User Response: The user receives a copy of the created webpage. 

25. What are the Spring MVC Framework’s primary benefits?

Ans:

• Modular Architecture: By encouraging a modular design that divides concerns (Model, View, Controller), Spring MVC facilitates the development, testing, and maintenance of applications.
• Flexibility: A variety of view technologies are supported, enabling developers to select the most appropriate one .respective project, like FreeMarker, JSP, or Thymeleaf
• Reusable Components: The framework promotes the development of reusable components, which results in effective application development and maintenance.

26. What fundamental issue does the Spring MVC framework resolve?

Ans:

By offering a structured architecture that divides concerns (Model, View, Controller) and streamlines the development process, the Spring MVC framework effectively addresses the fundamental issue of the efficient and structured creation of online applications. Prior to Spring MVC, web application developers frequently struggled to handle the intricacy of interactions between many components, making apps challenging to scale, test, and manage.

27. Describe the main characteristics of the Spring Framework.

Ans:

• It offers good handler mapping, binding, view resolution, and validation customization.
• Spring MVC allows defining an infinite controller method, significantly increasing the application’s adaptability and flexibility.
• It can set up the classes and framework as beans efficiently. It separates the responsibilities and functional roles.
• Using a map facilitates the model’s transfer. In addition to supporting velocity, JSTL, and JSP, the user can choose theme resolution and locale.

28. Is it possible to modify the integrated Tomcat server’s default port in Spring Boot?

Ans:

The application properties file can be modified by adding a property called ‘server.port’ and assigning it to a chosen port. For example, ‘server.port=8081’ can be specified to set the port to 8081. The application properties file will be loaded immediately upon specifying the port number. The application will be implemented using Spring Boot with the designated configurations.

29. What are the advantages of the Spring MVC framework compared to other MVC frameworks?

Ans:

• Every role in Spring MVC has a dedicated object. As a result, it clearly defines the roles.
• Within Spring MVC, a particular framework base class can be expanded by using code as commands rather than mirroring it.
• Spring MVC offers easy-to-use and robust configuration options for JavaBeans application classes and the framework.
• Adaptable binding, validation, view resolution, and handler mapping. Locale and theme resolution customization.

30. What does the Spring MVC framework’s DispatcherServlet do?

Ans:

The DispatcherServlet implements the Front Controller design pattern, which manages all incoming web requests for a Spring MVC application. The Front Controller paradigm is a popular pattern in online applications. It takes in all requests and forwards them to other application components for processing. Web requests are routed to the Spring MVC controllers using the  DispatcherServlet in Spring MVC. 

31. Describe Spring MVC’s Front Controller.

Ans:

The Front Controller is a class called DispatcherServlet. It is in charge of overseeing the application’s flow and forwarding the request to the relevant Controller. The DispatcherServlet class is the Front Controller in Spring Web MVC, managing the overall request handling process. It intercepts all incoming requests, allowing for centralized processing and providing features like view resolution, exception handling, and integration with other components of the framework. This design simplifies the architecture and enhances the maintainability of the application.

32. Does an application context facilitate the DispatcherServlet’s instantiation?

Ans:

• An application context is not used to instantiate the DispatcherServlet. Instead, it is instantiated by Servlet containers such as Tomcat or Jetty. 
• To use the DispatcherServlet, define it in the web.xml file. 
• Instead of building its internal web application context, DispatcherServlet may be injected with one. 
• This is helpful in environments supporting Servlet 3.0+, which allows programmatic servlet registration. 
• Examples. For further information, see the Javadoc for DispatcherServlet(WebApplicationContext).

33. What is the Spring MVC root application context?

Ans:

The context loaded via ContextLoaderListener is the root application context in Spring MVC. Globally available resources should be part of this context, whereas servlet-specific resources are initialized using the DispatcherServlet. Multiple DispatcherServlet instances are permitted in a Spring MVC web application. Thus, a root context may belong to several contexts, each unique to a particular servlet.

34. What does Spring MVC’s ContextLoaderListener do?

Ans:

• In Spring MVC, the ContextLoaderListener loads, constructs, and inserts the ApplicationContext into the ServletContext. 
• It also connects the ApplicationContext’s lifecycle to the ServletContext’s lifecycle.  
• The getServletContext() function can be used to obtain ServletContext from WebApplicationContext.

35. What is the purpose of the Controller annotation?

Ans:

Using the Controller annotation, a class can be designated as acting as a controller. Its primary function is to serve as a stereotype by outlining the role of the annotated class. Using the annotation @Controller, a particular class as a controller in the Spring framework. Keep in mind that Java annotations are similar to code metadata. They provide context to the code, which aids the framework in doing its job.

36. What indicates a class as a controller class in Spring MVC?

Ans:

To declare a class as a controller in Spring MVC, must include the Controller annotation on the class name, as demonstrated below. Manager class ClassName{} using the Controller and RequestMapping annotations. This class is identified as Controller by the Controller annotation. The supplied URL name is mapped to the class using the Requestmapping annotation.

37. How can a controller be made without the need for an annotation?

Ans:

• In Spring MVC, the Controller is defined using the Controller annotation. 
• However, by adding the Component annotation to the controller classes, it is possible to create a controller without utilizing the Controller annotation.
• The ResponseBody is unnecessary because the Controller is marked with the RestController annotation. 
• The controller class’s request processing methods automatically deserialize return objects into HttpResponse.

38. What is the method to associate a URL with a controller class and its method in Spring MVC?

Ans:

The method to link a URL with a controller class and its method in Spring MVC is by using the @RequestMapping annotation. This annotation can be applied at both the class and method levels to specify the URL patterns that will trigger the controller. For instance, using @RequestMapping(“/example”) at the class level and @RequestMapping(“/test”) at the method level results in a combined mapping for the URL /example/test. Additionally, it allows for the specification of HTTP methods like GET or POST to further refine the mapping.

39. List some acceptable return kinds for a controller method.

Ans:

• ModelAndView: Represents both the model and the view, allowing the controller to specify both data and the view to render.
• String: A view name that resolves to a specific view template, directing the framework to render that view.
• ResponseEntity: Provides a way to customize the HTTP response, including status code, headers, and body.
• HttpEntity: Similar to ResponseEntity, but without the status code; used for both request and response body manipulation.

40. What Does Spring MVC’s Model Mean?

Ans:

The Model in Spring MVC serves as a reference for the data needed for rendering. It functions as a container for the application’s data, which may be in any format, including objects, strings, database information, etc. The model is always built and provided for viewing in Spring MVC. It acts as a bridge between the controller and the view, ensuring that the necessary data is available for rendering the user interface. Additionally, the model can be updated dynamically based on user input or application state, facilitating a responsive user experience.

41. What does a view represent in Spring MVC?

Ans:

In a Spring MVC application, a view is an interface whose implementations expose the model and rendering context. It is employed to provide data to the user in a specific format. A view can be rendered as HTML, JSON, XML, or other formats, depending on the requirements of the application. In Spring MVC, a view resolver resolves a view, and a view name addresses a view, facilitating the separation of the controller logic from the presentation layer for better maintainability.

42. What is a ViewResolver in Spring MVC?

Ans:

• ViewResolver makes working with views in Spring MVC possible. 
• It makes it possible to render models in the browser without attempting to use a particular view technology. 
• It offers a mapping of view names to their corresponding views.
• Additionally, ViewResolver can support multiple view technologies simultaneously, enabling developers to switch or mix different view types as needed.

43. What pattern does the View Resolver follow?

Ans:

A J2EE paradigm called View Resolver enables a web application to dynamically select its view technology, such as JSF, XSLT, Tapestry, HTML, and JSP. In this case, the Controller returns the view name, and the View Resolver stores a mapping of various views. The View Resolver then receives the mapping to choose a suitable view. This method makes more flexibility and concern separation possible, making it simple for developers to move between several display technologies without changing the underlying logic.

44. How can the Spring MVC controller obtain HTML form data?

Ans:

Using the ‘@RequestParam’ annotation, a controller in Spring MVC can map request parameters to method arguments and retrieve HTML form data, providing direct access to form fields. Alternatively, you can use a command object, which maps form fields to JavaBean properties, making managing numerous fields easier. The info is automatically filled in after the form is submitted. This approach enhances the readability and maintainability of the code.

45. Which ViewResolver types are available in Spring MVC?

Ans:

The various ViewResolvers are as follows:

• ViewResolver Abstract Catching
• XMLViewResolver
• BundleViewResolver for Resources
• ViewResolver with URL
• ViewResolver for Internal Resources
• FreeMakerViewResolver 

46. How is the appropriate View selected during the rendering stage in Spring MVC?

Ans:

After receiving logical view names from the Controller, the DispatcherServlet checks with the ViewResolver to determine the correct View. Depending on how the ViewResolver is implemented, the logical View is resolved into a physical resource, such as a JSP page. Once the physical resource is identified, it is rendered to the client. This process allows for flexibility in the types of views that can be used, supporting various technologies like Thymeleaf, PDF generation, or plain HTML.

47. Why should a ViewModel be utilized?

Ans:

The following are some advantages of applying the MVVM pattern: It may be difficult or dangerous to modify an old model implementation if it encapsulates the current business logic. Here, the view model serves as an adapter for the model classes, keeping you from modifying the model code significantly. Additionally, MVVM promotes a clear separation of concerns, making managing and testing different components easier.

48. What kinds of annotations are utilized to handle which types of incoming HTTP request methods?

Ans:

• @GetMapping: Used to handle HTTP GET requests, typically for retrieving data from the server.
• @PostMapping: Utilized for HTTP POST requests, often used for submitting data to the server for processing.
• @PutMapping: Handles HTTP PUT requests, commonly used for updating existing resources on the server.
• @DeleteMapping: Used for HTTP DELETE requests, primarily for removing resources from the server.

49. What does Spring MVC’s RequestParam Annotation serve as?

Ans:

To extract and map the query parameter to the method parameter in your Controller, utilize Spring MVC’s RequestParam Annotation. It retrieves the parameter’s value from the form request. The RequestParam annotation in Spring MVC automatically links the form data to the parameter in the supplied method. Thus, it disregards the HttpServletRequest object’s need to read the provided data.

50. What does Spring MVC’s PathVariable Annotation serve to accomplish?

Ans:

In Spring MVC, the values of URI template variables are extracted using the PathVariable annotation, which sets their values in the method parameter. To obtain data from the URL path, the PathVariable annotation is utilized. Placeholders defined in the request mapping URL can be tied to method parameters annotated with PathVariable. This functionality enables the use of dynamic values from the URL in the code.

51. What is the Spring MVC ResponseBody annotation used for?

Ans:

In Spring MVC, the ResponseBody annotation informs the Controller that the returned object is serialized and immediately returned to the HttpResponse object. The HTTP request body data, frequently in XML or JSON format, is extracted using RequestBody, deserializing it into a Java object. To extract specific parameter values from the request URL or submitted form data, use RequestParam.

52. How can data be read from the form differently in Spring MVC?

Ans:

• The form data is read using the RequestParam annotation, which ties it to the Controller’s method parameter.
• Annotation ModelAttribute The form data can be read and bound to a Java object with the help of the ModelAttribute annotation.
• To read HTML from user data, the HttpServletRequest interface—a Java interface—is utilized.

53. What are the perspectives on Spring MVC validations?

Ans:

Spring MVC calls user-input data validation validation. It is among Spring MVC’s most crucial components. It limits what the user can enter as data. Bean Validation API must be used to validate the user input. A custom validation annotation can also be specified at the class level to validate several class attributes. Finding the matching values in two class fields is a typical use case.

54. What is meant by the Bean Validation API?

Ans:

This Java specification allows limitations to be applied to a method, class, or field of a JavaBeans component in the form of annotations. To confirm a length, regular expression, number, etc.The JavaTM Enterprise Edition 6 platform introduces the Bean Validation API as a standard mechanism to validate JavaBeans in an application’s display, business, and data access layers. JavaBeans were validated in each tier prior to the Bean Validation definition.

55. What key distinction exists between Controller and RestController?

Ans:

• The components annotation is specialized into the Controller and Rest Controller. The ResponseBody annotation is the primary difference between them.
• Not every Controller receives an independent call from Controller to ResponseBody. On the other hand, the Rest Controller calls ResponseBody to all controller functions while using both Controller and ResponseBody.

56. What do the annotations RequestBody and ResponseBody mean?

Ans:

@RequestBody can be bound to a method parameter, indicating that the supplied parameter needs to be translated from the incoming request. This allows for easy handling of complex data structures like JSON or XML. The response body of the controller method consists of its serialized return type, which @ResponseBody ensures. This annotation facilitates seamless conversion between Java objects and HTTP responses, enhancing communication between the client and server.

57. What do the terms “Model,” “ModelMap,” and “ModelAndView” mean?

Ans:

• Model and View can be considered a bucket containing both model map and View, and the model as an interface and mode map as a class. ModelMap is a class, whereas Model is an interface. 
• ModelAndView is a container for a View object and a ModelMap. It enables a controller to return both as a single value.
• Additionally, ModelAndView facilitates the separation of concerns, enabling developers to manage the data and the presentation layer more effectively within a Spring MVC application.

58. What do SessionAttributes and SessionAttribute signify?

Ans:

Web applications’ session data is managed by using SessionAttributes and SessionAttributes. Several model attributes are kept in the session and made accessible for subsequent requests within the same session when utilizing SessionAttributes. To connect specific model attributes from a session to the method argument, use the SessionAttribute class.

59. What do spring MVC tiles mean?

Ans:

Spring MVC Tiles is an integration of the Apache Tiles library with the Spring MVC framework. Using Apache Tiles, a templating framework, it is possible to create reusable views and layouts for internet-based applications. This approach is beneficial for designing consistent, modular user interfaces. With Spring MVC Tiles, web pages can be constructed by piecing together smaller, reusable “tiles” into a more extensive page layout. Each tile represents a section of the page, such as content, sidebar, header, or footer.

60. What does EnableWebMVC mean? Describe its objective.

Ans:

• Use the EnableWebMVC annotation to activate Spring MVC in an application. It is primarily employed in configuration classes. 
• EnableWebMVC’s primary goal is to handle and process requests and responses. 
• It specifies callback methods to personalize the Java-based Spring MVC configuration activated by the EnableWebMvc setting. 

61. What is the purpose of Spring MVC?

Ans:

A Spring MVC Java framework is used to create web apps. It adheres to the model-view-controller design pattern and incorporates all of the fundamental Spring framework features, including Dependency Injection and Inversion of Control. This modular architecture promotes a clear separation of concerns, making managing and testing applications easier. Additionally, Spring MVC provides extensive support for RESTful web services, enabling the development of scalable and maintainable APIs.

62. What are Spring MVC’s layers?

Ans:

The Spring MVC architecture consists of the Presentation Layer (Controller), Business Logic Layer (Service), Data Access Layer (Repository or DAO), Model Layer, View Layer (JSP, Thymeleaf, etc.), and Integration Layer. This tiered strategy encourages modular architecture and improves web application maintainability. Each layer is responsible for specific functionalities, allowing for easier testing and development.

63. What is the Spring MVC life cycle?

Ans:

The Spring MVC life cycle starts when a client sends a request to the server. The DispatcherServlet intercepts this request and forwards it to the appropriate Controller based on URL mappings. The Controller handles the request, typically interacting with the Service layer for business logic and the Repository layer for data access. Once the processing is complete, the Controller returns a ModelAndView object, which the DispatcherServlet uses to determine the correct ViewResolver and generate the response.

64. What are Spring MVC’s salient characteristics?

Ans:

• Spring MVC has features that allow business code to be reused without duplication. Also adjust the view resolution and handler mapping. 
• This will enable adaptable model transfer through Map. 
• It offers validation and binding customization. 
• Customize the application classes and framework by using Spring MVC.

65. What distinguishes spring boot from Spring MVC?

Ans:

Spring Boot distinguishes itself from Spring MVC by providing an opinionated framework that streamlines configuration and setup. It features auto-configuration, minimizing the need for extensive XML configurations. With an embedded server, Spring Boot allows applications to run independently without relying on external web servers. It also emphasizes convention over configuration, facilitating quicker project initiation. In contrast, Spring MVC demands more manual setup and configuration efforts.

66. What subjects are covered in depth in Spring MVC?

Ans:

• Spring MVC covers controllers, Views, Models, Request Mapping, Data Binding, Validation, Interceptors, and Exception Handling. 
• These subjects offer fundamental building blocks for using the Spring MVC framework to create web applications.
• Additionally, it supports the integration of various view technologies, enabling developers to choose the best rendering approach for their applications.

67. What is the purpose of the Spring Framework?

Ans:

• Spring is a practical open-source, somewhat lightweight, linked Java framework designed to make creating enterprise-level applications less complicated. 
• The “framework of frameworks” moniker comes from Spring’s ability to support numerous other significant frameworks, including JSF, Hibernate, Structs, EJB, and others.
• About 20 modules total, which can be broadly classified into the following categories:

 68. What characteristics does the Spring Framework have?

Ans:

• Spring’s AOP (Aspect Oriented Programming) feature facilitates unified development by guaranteeing that the business logic of an application is isolated from other system functions.
• Spring offers an incredibly adaptable MVC web application framework with simple framework-switching capabilities.
• Offers configuration creation and management services and application object lifecycle definition.
• One unique design principle in Spring is IoC (Inversion of Control), which allows objects to declare their dependencies instead of searching for ways to create dependent objects.

69. What is a configuration file for Spring?

Ans:

A Spring configuration file is an XML file that primarily describes the classes’ Configuration and links to one another, along with their information. The configuration files in XML are more concise and clear. Offers configuration creation and management services and application object lifecycle definition. Spring offers an easy-to-use API for converting technology-specific exceptions (thrown by Hibernate, JDBC, or other frameworks) into unchecked, consistent errors.

70. How may a particular auto-configuration class be turned off?

Ans:

• For this, utilize the EnableAutoConfiguration exclusion attribute as demonstrated below:
• Using exclusion = {AutoConfiguration.class}, EnableAutoConfiguration
• The fully qualified name can be set as the value for excludeName if the class is not specified on the classpath. By utilising EnableAutoConfiguration(excludeName={Foo.class}) and “excludeName”
• The application allows for additions. Keep it separated with commas to add properties and numerous classes.

71. Is it possible to exclude any package without the basePackages filter?

Ans:

Yes, excluding packages without using the ‘basePackages’ filter in Spring is possible. This can be done using the ‘exclude’ attribute in annotations such as ‘@ComponentScan’. Developers can prevent certain packages from being scanned and processed by specifying which classes or configurations to exclude. Moreover, Spring provides comprehensive control over package exclusions through a programmatic setting. This adaptability makes it easier to modify the application context to meet particular needs better and improve efficiency.

72. Describe the distinction between setter and constructor injection in question 

Ans:

• Within  Partial Injection is permitted in setter injection but not constructor injection.
• Unlike setter injection, which does not override the setter property, constructor injection does not.
• Any modifications made result in creating a new instance via constructor injection. Setter injection prevents the creation of new instances.
• Constructor injection is the recommended method if the Bean has numerous characteristics. Setter injection is recommended if it has minimal qualities.

73. What are Allowances?

Ans:

• The Spring IoC container is in charge of these objects, which serve as the framework for the user’s application.
• IoC containers are used to instantiate, configure, wire, and manage spring beans.
• The configuration metadata that users provide to the bean creation container (using Java annotation settings or XML annotations).

74. What does the “Inversion of Control” (IoC) container mean?

Ans:

The foundation of the Spring Framework is the Spring container. Dependency Injection (DI) is the spring container’s mechanism for managing the application components. It creates objects, wires them up, configures their general life cycles, and manages them. Java annotations, Java code, or XML configuration can all be used to give the spring container instructions.

75. What does Dependency Injection refer to?

Ans:

Dependency Injection (DI) is a design pattern that facilitates Inversion of Control (IoC) in software development. It enables a class to obtain its dependencies from an external source instead of instantiating them internally. This approach encourages loose coupling, resulting in more modular and testable code. DI improves maintainability by allowing developers to replace implementations without altering the dependent classes. Ultimately, it simplifies configuration and fosters better separation of concerns within applications.

76. What is the distinction between setter and constructor injection?

Ans:

• Partial Injection is permitted in setter injection but not in constructor injection. In contrast, the constructor injection does not override the setter property. This isn’t the case with setter injection.
• Any modifications made result in creating a new instance via constructor injection. Setter injection prevents the creation of new cases.
• Constructor injection is the recommended method if the Bean has numerous characteristics. Setter injection is recommended if it has minimal qualities.

77. What Are Spring Vegetables?

Ans:

• The Spring IoC container is in charge of these objects, which serve as the framework for the user’s application.
• IoC containers are used to instantiate, configure, wire, and manage spring beans.
• The configuration metadata that users provide to the container (via XML or Java annotation configurations) is used to build beans. To learn the basics of Java, check out Scaler Topics’ Free Java Spring Boot course.

78. How does the spring container receive the configuration metadata?

Ans:

The Spring container obtains configuration metadata from several formats, including XML files, Java annotations, and Java configuration classes. XML files specify beans and their properties in a structured manner, while Java annotations like @Component and @Autowired offer a more concise way to configure directly in the code. Java configuration classes, marked with @Configuration, allow developers to define beans through Java methods.

79. Which bean scopes are offered in the Spring?

Ans:

• Singleton: When utilizing this, the bean definition’s scope is limited to one instance per IoC container.
• Prototype: In this case, an object instance can be the scope of a single bean specification.
• Request: An HTTP request is the scope of the bean specification.
• Session: In this case, HTTP-session is the scope of the bean specification.
• Worldwide Session: The Range of a Global HTTP session is the Bean’s definition in this case.

80. Describe how beans grow in a container at the Spring Bean Factory.

Ans:

• The Bean is instantiated by the IoC container using the bean definition in the XML file.
• As stated in the bean definition, Spring uses dependency injection to fill all properties.
• The bean factory container invokes setBeanName(), which requires the appropriate Bean to implement the BeanNameAware interface and takes the bean ID as input.
• If the Bean implements the BeanFactoryAware interface, the factory then calls setBeanFactory() and passes an instance of itself.

81. What is understood by Bean Wiring?

Ans:

The term “bean wiring” refers to mixing beans inside a Spring container. When wiring beans, the Spring container should know which beans are required and how they depend on one another. This is provided via Java code-based configuration, XML, and annotations. Additionally, proper bean wiring facilitates the management of dependencies, promoting loose coupling between components. This results in more maintainable and testable code, as the container can easily manage and inject the necessary dependencies at runtime.

82. Describe auto wiring and list its many modes.

Ans:

The IoC container authors the relationships between the application beans. Spring allows collaborators to examine the BeanFactory’s contents to determine which Bean requires automatic wiring. Some of this process’s modes are:

• No: This is the default value and indicates no auto wiring. For wiring, an apparent bean reference must be utilized.
• byName: The Dependency is injected depending on the Bean’s name. By the Configuration, this matches and wires its attributes with the beans defined by the same names.
• byType: Depending on the type, this injects the bean dependency.

83. What are auto wiring’s limitations?

Ans:

• Ambiguity Issues: If multiple beans of the same type are present in the context, Spring may not know which one to inject, leading to a runtime exception.
• Lack of Explicit Control: Auto-wiring reduces the explicitness of bean dependencies, making it harder to understand the wiring at a glance and potentially complicating debugging.
• Limited Constructor Injection: Auto-wiring primarily supports field and setter injection, which may only suit some design patterns, particularly when constructor injection is preferred for mandatory dependencies.

84. What does the phrase “Spring Boot” refer to?

Ans:

The term “Spring Boot” refers to an enhancement of the Spring framework designed to simplify the creation and deployment of Spring applications. It offers a variety of conventions and default settings that minimize boilerplate code, streamlining the development process. Spring Boot allows applications to run independently with embedded servers without needing separate server installations. It also provides a wide range of starter dependencies, facilitating the inclusion of required libraries.

85. Describe the benefits of developing applications with Spring Boot.

Ans:

• Spring Boot facilitates the development of stand-alone apps that require no configuration of WAR files and may be launched with java.jar.
• Maven configuration can benefit from specific “started” POMs provided by Spring Boot.
• Offers direct embedding of Tomcat, Jetty, Undertow, and other web servers.
• Auto-Configuration: This feature enables an application to be configured automatically per the dependencies on the classpath. The goal of developing Spring Boot was to write fewer lines of code.

86. What annotations manage the various incoming HTTP request methods?

Ans:

• @GetMapping: Handles HTTP GET requests, typically used to retrieve data from the server.
• @PostMapping: Manages HTTP POST requests, commonly used for submitting data to the server.
• @PutMapping: Handles HTTP PUT requests, typically used for updating existing resources.
• @DeleteMapping: Manages HTTP DELETE requests, used to remove resources from the server.

87. What characteristics does Spring Boot offer?

Ans:

• CLI for Spring Boot: This Spring Boot CLI: This eliminates boilerplate code and lets write Spring Boot applications using Groovy or Maven.
• Starter Dependency: This feature allows Spring Boot to group similar dependencies, which gradually boosts output and lessens the strain on
• Spring Initializer: This web application aids in the creation of an internal project structure by developers. This functionality spares the developer from manually setting up the project’s structure.
• One helpful feature is Auto-Configuration, which loads the default configurations based on the project are working on. This method avoids unnecessary WAR files.

88. What internal functions does the SpringBootApplication annotation serve?

Ans:

According to the Spring Boot documentation, the SpringBootApplication annotation can be used in place of the Configuration, EnableAutoConfiguration, and ComponentScan annotations, along with their default characteristics. This reduces the number of lines of code by allowing the developer to use a single annotation rather than several. Nonetheless, use these annotations in accordance with our projects’ requirements because Spring offers loosely coupled capabilities.

89. What happens when a Spring Boot application is executed as a “Java Application”?

Ans:

As soon as the application detects that a web application is running, it starts the Tomcat server automatically. It automatically manages configuration and dependencies without specifying the version of those requirements. Profile-specific properties: The YAML file or the application-{profile}.properties file is used to load these properties. The {profile} placeholder denotes an environment or an active profile, and the file is located in the same place as the non-specific property files.

90. Where may the external Configuration come from?

Ans:

By utilizing Spring Boot’s external configuration functionality, developers can run the same application in many settings. To list the necessary configuration properties for each environment, this uses environment variables, properties files, command-line arguments, YAML files, and system properties. The sources of external Configuration are as follows:

• Command-line properties: Spring Boot adds properties to the collection of environment properties after supporting command-line arguments and converting them to properties.
• Application Properties: Spring Boot currently looks for the YAML file or application properties file. To load the properties, navigate to the Configuration, classpath root, or application directory.