Table of Contents
The following are the Spring Interview Questions which discuss the top 50+ questions with proper explanation.
A spring is a framework designed to assist Java programmers in developing code. It offers features such as an IOC (Inversion of Control) container, a Dependency Injector, an MVC (Model-View-Controller) flow, and numerous other APIs tailored to Java developers.
Execution of an aspect can be likened to a performance on a stage. An advice serves as a method of teaching your application a new skill. These teachings are typically introduced at specific moments known as “joinpoints.”
In the Spring framework, beans are the fundamental building blocks of an application, representing various components and services. The term “scope” refers to the lifecycle and visibility of a bean within the Spring container. Among the different scopes available, the default scope is Singleton. When a bean is configured with Singleton scope, a single instance of that bean is created and shared throughout the entire application context.
This means that every time the application requests the creation of a bean with Singleton scope, the Spring container provides the same instance, promoting efficient resource utilization and maintaining consistency across the application. However, developers should be cautious when using Singleton scope for beans that require unique states or concurrent access, as the shared instance might lead to unintended side effects. For scenarios where distinct instances are needed, developers can explicitly configure beans with other scopes such as Prototype, Request, Session, or Custom scopes to suit the specific requirements of their application.
Spring supports two main types of transaction management:
Declarative Transaction Management: This approach involves configuring transactions through XML configuration or annotations. Developers specify the transactional behavior for methods or classes using metadata, and Spring automatically manages the transactions accordingly. It offers a more concise and modular way of handling transactions, separating the transactional concerns from the business logic.
Programmatic Transaction Management: In this approach, developers explicitly manage transactions within the application code using Spring’s transaction management APIs. They have full control over when to start, commit, or roll back transactions. While it provides more fine-grained control, it can also result in more verbose code and a mixing of transactional and business logic.
Both approaches have their merits and are suitable for different scenarios. Declarative transaction management is often preferred for its cleaner separation of concerns and reduced boilerplate code, while programmatic transaction management might be used when specific transaction handling is required or in legacy applications.
Spring Interview Questions selected for interview preparation for jobs.
Singleton beans are not inherently thread-safe in the Spring framework. While a singleton bean ensures that there is only one instance of the bean in the application context, it doesn’t guarantee thread safety by default. If multiple threads concurrently access and modify the state of a singleton bean without proper synchronization, it can lead to data inconsistencies and unexpected behavior.
Developers should take appropriate measures, such as using synchronized blocks or employing thread-safe classes and techniques, to ensure the thread safety of singleton beans when needed. Additionally, consider using other bean scopes, like prototype, in scenarios where thread safety is a primary concern.
Spring Interview Questions selected for interview preparation for jobs.
The Spring framework offers a range of benefits, including:
The Bean Factory serves as the fundamental component within the Spring framework. It functions as a lightweight container responsible for loading bean definitions and overseeing bean management. These beans are configured through XML files and primarily manage singleton-defined instances. Furthermore, the Bean Factory takes charge of lifecycle methods and the injection of dependencies. Additionally, it plays a role in eliminating ad hoc singletons and factories.
Bean wiring refers to the process of establishing connections or relationships between various application components, specifically the beans within a Spring container. This enables these beans to interact and collaborate effectively within the Spring framework.
Spring Interview Questions selected for interview preparation for jobs.
Spring MVC, or Spring Model-View-Controller, refers to a singular shared controller instance that manages request-type controllers and interceptors within the Inversion of Control (IoC) container. This architecture supports the utilization of multiple Dispatcher Servlets, enabling them to share the application context interface while maintaining separation in the class-based interface.
Spring Interview Questions selected for interview preparation for jobs.
The following represent the diverse event types for listeners:
Singleton Bean: A singleton bean in Spring refers to a scenario where only one instance of the bean is created within the application context. This single instance is shared among all the requesting components. Any subsequent requests for that bean will result in the same instance being returned. Singleton beans are suitable for stateless objects or when a single shared instance is desired for efficiency.
Prototype Bean: On the other hand, a prototype bean involves creating a new instance of the bean for each request made to the Spring container. This means that every time a component requests the prototype bean, a distinct instance is returned. Prototype beans are ideal for stateful objects or scenarios where diverse instances are required, ensuring independence and isolation.
Spring Interview Questions selected for interview preparation for jobs.
The Spring framework facilitates two primary forms of dependency injection:
At the heart of the Spring framework lies the core container module, which forms the foundation for its fundamental functionalities. Serving as the cornerstone of the entire Spring framework, this module is pivotal in shaping its architecture and capabilities.
The AOP module within the Spring framework is tailored for applications that leverage Spring’s capabilities. It incorporates support from the AOP Alliance to establish seamless compatibility between Spring and alternative AOP frameworks.
This module guides Spring in introducing annotations into the source code, elucidating how aspects should be implemented and applied.
The AOP Alliance represents an open-source initiative designed to encourage the widespread utilization of Aspect-Oriented Programming (AOP). Its primary objective is to establish a unified collection of components and interfaces, fostering enhanced interoperability across diverse AOP implementations.
The Spring configuration file, commonly referred to as the “Spring configuration file,” is an XML document that contains organized information. This file outlines the configuration and interaction details among various classes within the Spring framework.
Spring Interview Questions selected for interview preparation for jobs.
The Spring framework offers four distinct autowiring options:
Spring provides support for two main types of transaction management:
Spring Interview Questions selected for Java Spring framework.
Programmatic transaction management is recommended when dealing with a limited number of transactional operations. On the other hand, for handling a substantial volume of transactional operations, declarative transaction management is the preferred approach.
The Spring framework is indispensable due to its:
List of Modules Utilized in the Spring Framework:
Spring Interview Questions selected for interview preparation for jobs.
The RowCallbackHandler within the Spring framework serves the purpose of being invoked for every individual row contained within a ResultSet. Its main function revolves around the extraction of values from the ResultSet.
The Application Context module holds significant importance as it furnishes essential services such as EJB integration, remoting, JNDI access, and scheduling. It elevates Spring to the status of a comprehensive framework. Furthermore, it expands upon the concept of BeanFactory through the implementation of lifecycle events, support for internationalization messages, and validation.
The Aspect-Oriented Programming (AOP) module within the Spring framework provides a powerful and flexible way to address cross-cutting concerns in your application. Cross-cutting concerns are aspects of your software that affect multiple parts of your codebase, such as logging, security, and transaction management. AOP allows you to modularize and manage these concerns separately from the main business logic, promoting better code organization and maintainability.
Spring Interview Questions selected for interview preparation for jobs.
The BeanFactory interface is a core component of the Spring Framework that serves as a central registry for managing and providing instances of beans within an application. It acts as a container for holding various bean definitions, enabling the creation, configuration, and retrieval of bean instances based on these definitions. The BeanFactory interface forms the foundation for the broader application context in Spring, offering essential functionalities for inversion of control (IoC) and dependency injection, which are fundamental principles of the framework’s design philosophy.
Comparison between ApplicationContext and BeanFactory in Spring:
Auto-wiring is a feature in the Spring framework that allows you to automatically inject dependencies into Spring beans without explicitly specifying the wiring details in the XML configuration or Java code. In other words, Spring can automatically detect the dependencies a bean needs and provide them at runtime.
Auto-wiring simplifies the configuration process and reduces the need for manual wiring of dependencies, making the codebase more concise and maintainable.
Autowiring in Spring operates through five distinct modes:
To embark on your Spring journey, follow these steps:
Download Spring and Dependencies: Begin by downloading the necessary Spring framework and its associated files from the official Spring website.
Create Application Context XML: Construct an application context XML file. This document will define the beans (components) you intend to use and establish their interdependencies.
Integrate XML with web.xml: Integrate your application context XML file with the web.xml configuration of your project. This step ensures proper coordination between your Spring-defined beans and your web application.
Deploy and Run: Finally, deploy your application. Execute it to witness your Spring-powered components in action.
The life cycle of a bean involves two crucial stages:
Initialization: This stage includes the “Setup” method, which is invoked when the bean is being loaded into the container.
Destruction: The “Teardown” method is called when the bean is being unloaded from the container.
Spring Interview Questions selected for interview preparation for jobs.
Inversion of Control (IoC), also referred to as the dependency injection pattern, involves a shift in how object creation is managed. Rather than programmers directly creating objects, IoC designates this responsibility to an assembler. The assembler then handles the instantiation of necessary classes as required within this design pattern.
Various Types of Listener-Related Events:
An aspect, often referred to as logging, plays a vital role across the entire application. It represents a cross-cutting feature within an application through Aspect-Oriented Programming (AOP).
Spring Interview Questions selected for interview preparation for jobs.
A joinpoint refers to a specific moment within an application where an aspect can be seamlessly integrated. This juncture could encompass various scenarios such as the alteration of a field, the invocation of a method, or the occurrence of an exception. Within these instances, additional code from a new aspect can be introduced to imbue the application with fresh behaviors.
At this juncture, the aspect’s code can be seamlessly woven into the standard flow of the application, allowing for a modification of the existing behavior.
“Advice” refers to the implementation of an aspect in an application. It introduces new behavior to the application and is injected into the codebase at specific points called joinpoints.
In essence, advice serves as a way to convey fresh functionality to your application. Typically, this advice is integrated into the application precisely at the joinpoints.
A pointcut defines specific locations or conditions within a program’s execution flow where advice, such as additional functionality or behavior, can be applied.
Weaving involves the creation of a fresh proxy object by applying aspects to the target object.
Singleton Bean: A singleton bean corresponds to a solitary object instance within the Spring IOC container. This means that only one instance of the bean is created and shared across the entire container.
Prototype Bean: In contrast, a prototype bean associates a single bean definition with the potential to generate multiple object instances within the Spring IOC container. With a prototype bean, you can create any number of instances, each separate from the others, as per your requirements.
Weaving can be applied in the following contexts:
There are various forms of AutoProxying available, including:
These different AutoProxying methods serve distinct purposes within the Spring Framework.
Beans can be configured as singleton or prototype using the ‘singleton’ attribute within the bean tag. When the attribute is set to ‘TRUE’, the bean functions as a singleton; otherwise, it operates as a prototype.
Spring Interview Questions selected for interview preparation for jobs.
Here is a list of classes dedicated to controlling database connections:
DAO, which stands for Data Access Object, serves as a bridge between Java’s database connectivity and Object-Relational Mapping (ORM) entities. In Spring, the DAO is a fundamental component that facilitates connections with various data sources such as JDBC, Hibernate, JDO, JPA, Common Client Interface, and Oracle databases. It plays a crucial role in abstracting the underlying data access complexity and enables efficient interaction with databases and persistence layers.
Autoproxying in Spring involves the automatic generation of proxies for Spring users. This functionality is supported through the following two classes:
BeanNameAutoProxyCreator: This class facilitates the automatic creation of proxies based on bean names.
DefaultAdvisorAutoProxyCreator: This class is responsible for the automatic proxy creation using advisors.
These classes enable Spring to generate proxies seamlessly, enhancing the framework’s capabilities for users.
Metadata Autoproxying is a technique within the Spring Framework that leverages metadata to guide its operation. This process is influenced by source-level attributes, effectively encapsulating metadata within the source code itself. By centralizing metadata in a single location, this approach is primarily employed to facilitate declarative transaction support.
Spring Interview Questions selected for interview preparation for jobs.
In Spring, ‘Throws Advice’ addresses exception handling behavior. It is an interface that doesn’t require explicit method implementations.
For a class to implement this interface, it should possess a method with the following signature:
void sampleThrow(Throwable ex)
void sampleThrow(Method method, Object[] args, Object target, Throwable ex)
The Spring Framework offers a range of custom editors, including:
Spring Interview Questions selected for interview preparation for jobs.
The Spring framework offers several advantages, including:
Hibernate can be accessed through the Spring framework using the following methods:
IOC with Callback and Hibernate Template: This involves utilizing Inversion of Control (IOC) alongside a callback mechanism and the Hibernate Template class to interact with the Hibernate ORM.
AOP Interceptor and HibernateDaoSupport: Another approach is to employ an Aspect-Oriented Programming (AOP) interceptor along with the HibernateDaoSupport class, which extends Spring’s data access support and simplifies Hibernate integration.
Spring version 2.0 supports the following channels:
Spring Interview Questions selected for interview preparation for jobs.
Declarative transaction management is favored in Spring due to its minimal impact on application code, making it an ideal and lightweight container for managing transactions. This approach simplifies the management of transactional behavior without requiring extensive modifications to the codebase.
The BeanFactory embodies the factory pattern within the Inversion of Control (IoC) paradigm, enabling a clear segregation between an application’s dependencies and configuration on one hand, and its core code on the other.
Spring Interview Questions selected for interview preparation for jobs.
Spring beans can have different scopes, including:
Singleton: A single instance of the bean is created and shared throughout the application context.
Prototype: A new instance of the bean is created every time it is requested.
Request: A new instance is created for each HTTP request in a web application.
Session: A single bean instance is created and shared across a user’s session in a web application.
Global Session: This scope is specific to a global session in a Portlet context, where a single instance is shared across all portlets in the same session.
There are two primary methods to access Hibernate via Spring:
Inversion of Control with Hibernate Template and Callback: This approach involves utilizing the Hibernate Template, which offers a simplified way to work with Hibernate sessions and transactions. Additionally, callback mechanisms can be employed to manage specific operations within these sessions.
Extending HibernateDAOSupport and Applying AOP Interceptor: Another method involves extending the HibernateDAOSupport class provided by Spring. By doing so, you can leverage the benefits of Aspect-Oriented Programming (AOP) interception to manage cross-cutting concerns such as transaction handling and error management.
Integrating a Struts application with Spring can be achieved through two approaches:
Using ContextLoader Plugin: Configure Spring to manage beans through the ContextLoader
plugin and establish their dependencies within a Spring context file.
Explicit Retrieval of Spring Beans: Access Spring-managed beans directly by utilizing the getWebApplicationContext()
method.
Inversion of Control (IoC), also known as Dependency Injection, is a design pattern that transfers the control of class instantiation from the class itself to the assembler. In typical scenarios, a class creates instances of other classes when necessary.
However, in this pattern, the responsibility of instantiation is shifted to the assembler. The assembler will create instances of necessary classes as and when required. This promotes a more flexible and modular approach to constructing software components.
IoC, or dependency injection, offers significant benefits for application development:
These advantages collectively contribute to more efficient, maintainable, and well-structured software development.
An Inner Bean refers to a bean element that is directly enclosed within a property tag during the process of wiring beans. This encapsulation allows for a more concise configuration. However, the drawback of Inner Beans lies in their limited reusability and reprocessing capabilities. Once defined within a property tag, an Inner Bean cannot be easily reused or reconfigured, potentially limiting flexibility in certain scenarios.
Spring offers three injection types:
Spring Interview Questions selected for interview preparation for jobs.
The Spring framework offers the following benefits:
Lightweight Container: Compared to J2EE containers, Spring provides a lightweight container for managing application components.
Built-in Web MVC Framework: It includes a built-in framework for developing web applications following the Model-View-Controller architecture.
Loosely Coupled Applications: Spring facilitates the creation of loosely coupled applications, enhancing flexibility and maintainability.
Aspect-Oriented Programming: Spring supports aspect-oriented programming, enabling features like logging, transaction management, and security to be efficiently integrated.
XML Configuration: Configuration is easily written and understood using XML format.
Spring offers five types of Advice:
The PreparedStatementCreator serves as a frequently utilized interface for database data insertion. Through its createPreparedStatement()
method, a PreparedStatement is crafted and returned based on the supplied Connection argument, with built-in exception handling. Notably, this interface can be accompanied by another interface, SqlProvider, which features a getSql()
method for furnishing SQL strings to the JdbcTemplate. It is important to note that SQLExceptions are not managed by this interface.
SQLProvider serves a specific purpose through its singular method, getSql(), which is realized using implementations of PreparedStatementCreator. Its primary function revolves around aiding in debugging processes.
Spring Interview Questions selected for interview preparation for jobs.
NGINX Server Nginx, a popular open-source web server, excels at handling high traffic websites efficiently.… Read More
In the realm of web hosting, choosing the right web server is paramount. It acts… Read More
Are indispensable for ensuring smooth, precise linear motion in many industrial applications. Whether in robotics,… Read More
Cyber attacks are becoming more frequent, complex, and damaging. They can disrupt critical operations and… Read More
With the rise of new threats and the increasing complexity of IT environments, organizations need… Read More
1. Introduction In software design, managing complex systems can be challenging. The Facade Design Pattern… Read More
View Comments
I found some useful information in your blog, it was awesome to read, thanks for sharing this great content to my vision, keep sharing.