#spring boot actuator

[datasciencewithpythonemexo]

Spring Boot Interview Questions: Prepare for Success

Spring Boot has become one of the most popular frameworks in the Java ecosystem, streamlining robust and scalable web application development. Whether you’re a seasoned developer or just getting started, acing a Spring Boot interview can be a significant milestone in your career. To help you prepare effectively, here are the latest Spring Boot interview questions that will test your knowledge and give you a deeper understanding of how the framework works. These questions will be beneficial if you're pursuing a Spring Boot Certification Training Course at eMexo Technologies, in Electronic City Bangalore.

1. What is Spring Boot, and how is it different from Spring Framework?

This is a fundamental question that often appears in Spring Boot interviews. Spring Boot is an extension of the Spring Framework to simplify the development process. It eliminates the need for extensive XML configuration and provides default configurations to facilitate rapid application development. Spring Framework requires developers to configure components manually, while Spring Boot auto-configures them.

By understanding this, you can highlight how Spring Boot training in Electronic City Bangalore at eMexo Technologies helps developers focus more on writing business logic rather than dealing with complex configurations.

2. What are the main features of Spring Boot?

Spring Boot stands out due to several features:

Auto-Configuration: Automatically configures your application based on the libraries on the classpath.

Embedded Servers: It allows the deployment of web applications on embedded servers like Tomcat, Jetty, and Undertow.

Spring Boot Starters: Pre-configured templates that simplify dependency management.

Spring Boot CLI: A command-line interface that allows you to develop Spring applications quickly.

Actuator: Monitors and manages application performance.

These features make Spring Boot an attractive option for developers, which is why the best Spring Boot training institute in Electronic City Bangalore emphasizes hands-on experience with these functionalities.

3. What is the role of @SpringBootApplication in Spring Boot?

The @SpringBootApplication annotation is a core part of Spring Boot, often referred to as the ‘meta-annotation.’ It is a combination of three annotations:

@Configuration: Marks the class as a configuration class for Spring Beans.

@EnableAutoConfiguration: Enables Spring Boot’s auto-configuration feature.

@ComponentScan: Scans the components within the specified package.

This annotation is crucial to understanding Spring Boot’s internal architecture and its ability to simplify configuration.

4. What is Spring Boot Starter, and how is it useful?

A Spring Boot Starter is a set of pre-configured dependencies that simplify the inclusion of libraries in your project. For instance, spring-boot-starter-web includes everything you need for web development, like Spring MVC, embedded Tomcat, and validation support.

Starters save a lot of time, as they eliminate the need to find and include individual dependencies manually. When studying at eMexo Technologies, you’ll get an in-depth look at the variety of Spring Boot Starters available and their importance in building scalable applications.

5. What is a Spring Boot Actuator, and how is it used?

Spring Boot Actuator provides production-ready features to help monitor and manage your Spring Boot application. It offers a wide array of tools like health checks, metrics, and auditing endpoints. The actuator allows you to easily monitor application performance, which is a crucial aspect of microservices-based applications.

6. What are Microservices, and how does Spring Boot help in building them?

Microservices are small, independent services that work together in a larger application. Each service is responsible for a specific business functionality and can be developed, deployed, and maintained independently. Spring Boot simplifies the development of microservices by providing tools like Spring Cloud and Spring Boot Actuator.

7. How does Spring Boot handle dependency injection?

Dependency Injection (DI) is a key feature of the Spring Framework, and Spring Boot uses it to manage object creation and relationships between objects automatically. In Spring Boot, DI is usually handled through annotations like @Autowired, @Component, and @Service.

8. How can you configure a Spring Boot application?

Spring Boot applications can be configured in multiple ways:

application.properties or application.yml files.

Using the @Configuration classes.

Via command-line arguments.

Environment variables.

9. What are profiles in Spring Boot, and how are they used?

Profiles in Spring Boot allow developers to create different configurations for different environments. For example, you can have one profile for development, one for testing, and one for production. You can specify which profile to use by setting it in the application.properties file or as a command-line argument.

10. What are the limitations of Spring Boot?

Despite its many benefits, Spring Boot has some limitations:

Lack of control over auto-configuration can sometimes lead to unexpected behaviors.

Increased memory usage due to embedded servers.

Limited flexibility in large-scale applications that require extensive custom configuration.

Addressing these limitations demonstrates that you have a well-rounded understanding of the framework and can make informed decisions about when and where to use it.

11. How does Spring Boot handle security?

Spring Boot simplifies security through Spring Security, which can be easily integrated into your application. By adding the spring-boot-starter-security dependency, you can configure authentication and authorization in a few lines of code. You can also customize login, registration, and session management features.

12. What is the role of the Spring Initializr in Spring Boot?

The Spring Initializr is an online tool used to generate Spring Boot projects. It allows developers to choose the dependencies and configuration options before downloading the skeleton code. This tool speeds up the initial setup phase, saving time and effort.

In conclusion, being well-prepared for Spring Boot interviews is crucial, especially in a competitive job market. Whether you're taking a Spring Boot course in Electronic City Bangalore or aiming for Spring Boot Certification Training, knowing these key concepts will give you the edge you need. At eMexo Technologies, you’ll receive hands-on training, not just theory, preparing you to answer interview questions and excel in your career confidently.

Join Now: https://www.emexotechnologies.com/

[freshyblog07]

Top Spring Boot Interview Questions and Answers (2025 Edition)

Spring Boot has become the standard for building production-ready Java applications with minimal configuration. If you're preparing for a backend or full-stack developer role, having a good grip on common Spring Boot interview questions is a must.

In this post, we’ll walk you through the most frequently asked Spring Boot questions to help you ace your next interview.

📘 Want a complete list with detailed answers and code examples? 👉 Read the full guide here: Spring Boot Interview Questions – Freshy Blog

🔹 What is Spring Boot?

Spring Boot is an extension of the Spring framework that simplifies the development of Java-based applications by providing auto-configuration, embedded servers, and production-ready defaults.

🔸 Common Spring Boot Interview Questions

1. What are the main features of Spring Boot?

Auto Configuration

Starter Dependencies

Spring Boot CLI

Actuator

Embedded Web Servers (Tomcat, Jetty)

2. What is the difference between Spring and Spring Boot?

Spring Boot is a rapid application development framework built on top of Spring. It eliminates boilerplate configuration and helps developers get started quickly.

🔸 Intermediate Spring Boot Questions

3. What are Starter dependencies?

Starter dependencies are a set of convenient dependency descriptors that you can include in your application. For example:

<dependency>

  <groupId>org.springframework.boot</groupId>

  <artifactId>spring-boot-starter-web</artifactId>

</dependency>

4. What is Spring Boot Actuator?

Spring Boot Actuator provides production-ready features like monitoring, metrics, and health checks of your application.

🔹 Advanced Spring Boot Questions

5. How does auto-configuration work in Spring Boot?

Spring Boot automatically configures your application based on the dependencies you have in your classpath using @EnableAutoConfiguration.

6. How can you secure a Spring Boot application?

You can use spring-boot-starter-security and configure it with annotations like @EnableWebSecurity, along with custom authentication and authorization logic.

🔍 More Questions Covered in the Full Guide:

What are Profiles in Spring Boot?

What is the role of application.properties or application.yml?

How to implement exception handling in Spring Boot?

How to integrate Spring Boot with databases like MySQL, PostgreSQL?

👉 Get full coverage with examples, tips, and best practices: 🔗 https://www.freshyblog.com/spring-boot-interview-questions/

✅ Quick Tips for Spring Boot Interviews

Understand how dependency injection works

Be familiar with REST API development in Spring Boot

Practice building microservices

Explore Spring Security basics

Review annotations like @RestController, @Service, @Component, and @Repository

Final Thoughts

Mastering these Spring Boot interview questions can give you a solid edge in any technical interview. As Java continues to be a dominant backend language, Spring Boot remains a vital tool in the modern developer’s toolkit.

📘 Want to dive deeper? 👉 Visit the full interview question guide here: Spring Boot Interview Questions – Freshy Blog

[lakshmimonopoly1]

Building Scalable Web Applications Using Java Spring Boot

In today’s technology-driven world, developing scalable web applications is vital for business growth and sustainability. For aspiring developers, enrolling in the Best Java Training Institute in Hyderabad, Kukatpally, KPHB is a smart move toward building expertise in modern backend frameworks. One such powerful framework is Java Spring Boot.

Why Choose Spring Boot?

Spring Boot is an extension of the Spring framework that simplifies application setup with minimal configuration. It offers built-in features like embedded servers, auto-configuration, and starter dependencies, allowing developers to launch projects quickly and efficiently. This makes it easier to develop, test, and deploy scalable web applications.

Ideal for Microservices Architecture

One of the standout features of Spring Boot is its seamless support for microservices. It allows large applications to be broken into smaller, manageable services that can operate independently. This microservice approach enhances scalability, reduces downtime, and supports flexible deployments, making it ideal for cloud-native applications.

Monitoring and Performance

Spring Boot also includes tools like Spring Actuator, which provides detailed insights into application performance, health checks, and metrics. This level of visibility helps developers monitor and optimize applications in real-time, ensuring stability and responsiveness as the user base grows.

Conclusion

Java Spring Boot is a leading choice for developers who aim to build scalable, efficient, and high-performing web applications. To master Spring Boot and gain hands-on experience with real-time projects, consider joining Monopoly IT Solutions Pvt. Ltd—your trusted partner in career development and advanced Java training.

[govindhtech]

Spring AI 1.0 and Google Cloud to Build Intelligent Apps

Spring AI 1.0

After extensive development, Spring AI 1.0 provides a robust and dependable AI engineering solution for your Java ecosystem. This is calculated to position Java and Spring at the forefront of the AI revolution, not just another library.

Spring Boot is used by so many enterprises that integrating AI into business logic and data has never been easier. Spring AI 1.0 lets developers effortlessly integrate cutting-edge AI models into their apps, bringing up new possibilities. Prepare to implement smart JVM app features!

Spring AI 1.0 is a powerful and comprehensive Java AI engineering solution. Its goal is to lead the AI revolution with Java and Spring. Spring AI 1.0 integrates AI into business logic and data without the integration issues many Spring Boot-using enterprises confront. It lets developers use cutting-edge AI models in their apps, expanding possibilities.

Spring AI supports multiple AI models:

Images produced by text-command image models.

Audio-to-text transcription models.

Vectors are formed by embedding models that transform random data into them for semantic similarity search.

Chat models can edit documents and write poetry, but they are tolerant and easily sidetracked.

The following elements in Spring AI 1.0 enable conversation models overcome their limits and improve:

Use system prompts to set and manage model behaviour.

Memory is added to the model to capture conversational context and memory.

Making tool calling feasible for AI models to access external features.

Including confidential information in the request with rapid filling.

Retrieval Augmented Generation (RAG) uses vector stores to retrieve and use business data to inform the model's solution.

Evaluation to ensure output accuracy employs a different model.

Linking AI apps to other services using the Model Context Protocol (MCP), which works with all programming languages, to develop agentic workflows for complex tasks.

Spring AI integrates seamlessly with Spring Boot and follows Spring developers' convention-over-configuration setup by providing well-known abstractions and startup dependencies via Spring Initialisation. This lets Spring Boot app developers quickly integrate AI models utilising their logic and data.

When using Gemini models in Vertex AI, Google Cloud connectivity is required. A Google Cloud environment must be created by establishing or selecting a project, enabling the Vertex AI API in the console, billing, and the gcloud CLI.

Use gcloud init, config set project, and auth application-default login to configure local development authentication.

The Spring Initialiser must generate GraalVM Native Support, Spring Web, Spring Boot Actuator, Spring Data JDBC, Vertex AI Gemini, Vertex AI Embeddings, PGvector Vector Database, MCP Client, and Docker Compose Support to build a Spring AI and Google Cloud application. The site recommends using the latest Java version, especially GraalVM, which compiles code into native images instead of JRE-based apps to save RAM and speed up startup. Set application properties during configuration.characteristics for application name, database connection options, Vertex AI project ID and location for chat and embedding models (gemini-2.5-pro-preview-05-06), actuator endpoints, Docker Compose administration, and PGvector schema initialisation.

PostgreSQL database with a vector type plugin that stores data with Spring AI's VectorStore abstraction? Database schema and data can be initialised on startup using schema.sql and data.sql files, and Spring Boot's Docker Compose can start the database container automatically. Spring Data JDBC creates database interaction and data access entities.

The ChatClient manages chat model interactions and is a one-stop shop. ChatClients need autoconfigured ChatModels like Google's Gemini. Developers can create several ChatClients with different parameters and conditions using ChatClient.Builder. ChatClients can be used with PromptChatMemoryAdvisor or QuestionAnswerAdvisor to handle chat memory or VectorStore data for RAG.

Spring AI simplifies tool calls by annotating methods and arguments with @Tool and @ToolParam. The model evaluates tool relevance using annotation descriptions and structure. New default tools can be added to ChatClient.

Spring AI also integrates with the Model Context Protocol (MCP), which separates tools into services and makes them available to LLMs in any language.

For Google Cloud production deployments, Spring AI apps work with pgVector-supporting databases like Google Cloud SQL or AlloyDB. AlloyDB is built for AI applications with its high performance, availability (99.99% SLA including maintenance), and scalability.

FAQ

How is spring AI?

The Spring AI application framework simplifies Spring ecosystem AI application development. It allows Java developers to easily integrate AI models and APIs without retraining, inspired by LangChain and LlamaIndex.

Essentials and Ideas:

AI integration:

Spring AI integrates AI models with enterprise data and APIs.

Abstraction and Portability:

Its portable APIs work across vector database and AI model manufacturers.

Spring Boot compatibility:

It integrates with Spring Boot and provides observability tools, starters, and autoconfiguration.

Support the Model:

It supports text-to-image, embedding, chat completion, and other AI models.

Quick Templates:

Template engines let Spring AI manage and produce AI model prompts.

Vector databases:

It uses popular vector database providers to store and retrieve embeddings.

Tools and Function Calling:

Models can call real-time data access functions and tools.

Observability:

It tracks AI activity with observability solutions.

Assessing and Preventing Hallucinations:

Spring AI helps evaluate content and reduce hallucinations.

[shakshi09]

How does Spring Boot simplify development?

Spring Boot simplifies Java development by offering a streamlined, production-ready framework that reduces boilerplate code and configuration complexities. It is built on top of the Spring Framework but eliminates much of the setup and manual configurations required in traditional Spring applications. This leads to faster development, easier deployment, and improved productivity.

One of the core features of Spring Boot is its auto-configuration. Instead of manually defining beans or XML configurations, Spring Boot automatically configures your application based on the libraries present in your classpath. For example, if you include Spring Data JPA, it auto-configures database settings, assuming typical defaults, which can still be overridden as needed.

Spring Boot also comes with an embedded web server (like Tomcat, Jetty, or Undertow). This means developers can run web applications without deploying WAR files to an external server��just run the application as a Java program, and it serves content directly. This makes testing, debugging, and deployment much faster and simpler.

Additionally, Spring Boot includes starter dependencies, which are curated dependency sets for common tasks like web development, security, and data access. These starters remove the guesswork from version compatibility and help avoid dependency conflicts.

Another significant feature is the Actuator, which provides out-of-the-box endpoints for monitoring and managing applications. Developers can check application health, view metrics, and track usage statistics without writing custom code.

Spring Boot promotes opinionated defaults, meaning it guides developers toward best practices and proven design patterns, allowing them to focus more on business logic than infrastructure code.

Because of these advantages, Spring Boot is a critical skill for modern web application development in Java. Anyone aiming to master backend technologies should consider enrolling in a java full stack developer course to build strong expertise in Spring Boot and related technologies.

[luna-wing-cns274]

Performance Test 01

< L3 Hachiko: Are we live? >

[ COMP/CON Fox_3: Yes, ma’am. Transmitting video stream. ]

< Alright. When I start running, follow me with the camera. >

[ COMP/CON Fox_3: You got it. ]

< Thanks. Okay, commencing initial simulated performance test of the INUGAMI Mk. I NHP-controlled high-mobility fire support chassis. >

The video feed shows Hachiko’s quadrupedal mech crouching, inactive, in the center of a vast and impossibly level salt flat. A scorching sun burns overhead, and on the horizon, reddish mountains rise against the sky. Heat rises through the still air; the wind is completely disabled.

< L3 Hachiko: Booting system. >

A low whirr of actuators coming online, automatically cycling through their self-test protocols.

< Pre-sortie checks complete, all systems nominal. Primary and secondary fuel lines open, priming for fusion induction. >

From beneath the mech’s cowling and armor plating, a high-pitched whine of turbines begins to rise toward a fever pitch.

< Dual reactor ignition in 3…2…1… >

Across the empty expanse of salt, a stuttering roar ripples through the air. Hachiko’s INUGAMI stands, rising to its full height.

< Main and auxiliary reactors online. Spooling fusion thrusters. Somatosensory link active. >

As Hachiko takes control of the frame, she leans forward and back, stretching, testing her footing. Her claws leave enormous, three-toed prints in the salt. Every motion is natural and smooth, if a little uncertain.

< Oh, wow. I can really feel the mass. Like a subaltern, but kind of springy. There’s a lot of kick to these motive systems. That’s satisfying. Let’s see here… >

Rearing up, she balances on her hind legs for a few seconds. Swaying back and forth, she shuffles her feet, trying to control her center of gravity.

< Woh-hoh! Okay! Yeah, it’s definitely not great as a biped, but I think it’ll be manageable for jumping and climbing. I feel like a tail would be helpful for balance. Blast from the thrusters might be a problem, though. Heat shielding? I’ll figure something out. >

A cloud of salt powder rises around the mech as it thunders down to all fours and drops into a low stance, poised to spring.

< Alright, time for the main event. Throttle to 5%, bringing thrusters up. >

Both nacelles mounted at the chassis' hips scream to life. Channeled by vectored-thrust nozzles, a shimmering torrent of superheated air begins to stream from the engines.

< Hah. I came this close to requesting permission for takeoff just now. Force of habit. Taching up to 45% throttle—now. >

Leaping forward, mid-stride, the mech’s thrusters flash and discharge twin cones of orange plasma. Hachiko’s head dives as the thrust overwhelms her.

< ʷᵒʰ >

Inches from collision with the ground, Hachiko’s forelegs snap ahead and push off hard, propelling the mech into an awkward, bounding lope. Swaying drunkenly, swerving back and forth as she tries to control the axis of thrust along her spine, Hachiko picks up speed.

< Holy shit I’m so close to the ground, ohhhhh I don’t like this no, no, NO— >

One paw rolls to the side, slipping in the salt. In the space of a millisecond, Hachiko compensates by throwing the weight of her head to one side and adjusting the angle of the thruster nozzles. Emerging from the stumble, Hachiko steadies her gait.

< Ohhh, okay. Okay. C’mon, keep it together. >

She experiments with the thrusters, contracting and dilating the nozzles, adjusting their orientation by millimeters. After a few seconds, she settles on a configuration and launches into a low greyhound sprint, finally finding her stride.

< That’s it. That’s the sweet spot. I’ll figure this out yet. I can feel the aerodynamics kicking in, keeping me level. Throttle to 60%. >

The light of the engine blast shifts from orange toward violet, and the ceramics of the vector nozzles begin to glow dull red. Under acceleration, Hachiko covers greater and greater distance with each bounding stride. In her wake, a trail of molten salt glistens in the sunlight.

< This is incredible. It isn’t that I’m moving particularly fast, it’s the proximity to surface. Everything feels so close, so immediate.

Throttle to 80. Let’s see what this thing can do. >

Acceleration. Across Hachiko’s torso, radiator vanes snap out into the airstream, bleeding heat away from the reactor. In one corner of the camera display, a meter tracks her increasing speed. 800km/h, 900…

Laughter, a clear sound over virtual comms. There’s a frantic quality in Hachiko's voice.

1000 km/h. She no longer pretends to breathe. Sustained for an inhumanly long duration, her peals of laughter begin to rise in pitch.

1234 km/h. A cone of condensation forms around her as she pierces the sound barrier. Pushed to maximum throttle, the fusion thrusters discharge a torrent of plasma.

1400 km/h.

The sound coming through over comms no longer resembles a human voice. Glass bells ringing, a crystalline song of exultation.

[ COMP/CON Fox_3: Hachi? Core temp is critical. ]

Out of the symphony of ringing frequencies, words congeal.

< Who cares? >

1700 km/h. The mech begins to shudder. Her legs are a blur of motion underneath her, shot through with wisps of condensation as they tear through the supersonic airstream.

< Just a little more. >

1852 km/h.

[ COMP/CON Fox_3: Mach 1.5. Overspeed, ma’am. I’m seeing structural failures at— ]

For a split second, Hachiko’s song breaks into a dissonant shriek.

A jet of violet plasma erupts from her back, spraying molten metal into the air. Stumbling, the mech falls to its side with a deafening impact and begins to roll. Fragments of armor, structural alloys, and shattered ceramics are hurled away as the chassis begins to break apart.

In the next instant, the camera view is momentarily blinded by a flash of light. The image resolves into a fireball of superheated plasma.

Overhead, countless droplets of molten metal soar through the air, a cloud of sparks descending toward the empty landscape.

Ahead of the dissipating fireball, Hachiko’s humanoid avatar can be seen tumbling across the ground, impossibly holding together in spite of the forces she is being subjected to. After a few moments she slides to a halt, face-down in the dust with her light hardsuit entirely undamaged.

Staggering to her feet, Hachiko steadies herself on her digitigrade legs, struggling with the transition back to a bipedal stance.

Then, she wrenches the canine-modified helmet from her head, hurls it away, and screams with laughter. Molten metal raining down around her, she throws her head back and howls.

…

[ COMP/CON Fox_3: Initial performance test outcome: chassis destroyed, pilot casket suffers nonsurvivable trauma. Reason for failure: user error.

Test pilot comment:

“Withstood plenty more abuse than I thought it would. GMS builds these frames tough. I think I can make a few improvements to the setup from the data we generated.

It needs more performance trials, but you know what? I’m dying for a combat test. Ma’ii better be ready this time." ]

[codezup]

Unlock Real-time Monitoring with Spring Boot Actuator - A Comprehensive Guide

A Comprehensive Guide to Spring Boot Actuator for Real-Time Monitoring Introduction Spring Boot Actuator is a powerful tool for monitoring and managing Spring Boot applications. It provides a comprehensive set of features for real-time monitoring, including metrics, health checks, and debug information. In this tutorial, we will explore the implementation of Spring Boot Actuator in detail,…

[dickens-daily]

CHAPTER XII—GREENWICH FAIR

If the Parks be ‘the lungs of London,’ we wonder what Greenwich Fair is—a periodical breaking out, we suppose, a sort of spring-rash: a three days’ fever, which cools the blood for six months afterwards, and at the expiration of which London is restored to its old habits of plodding industry, as suddenly and completely as if nothing had ever happened to disturb them.

In our earlier days, we were a constant frequenter of Greenwich Fair, for years. We have proceeded to, and returned from it, in almost every description of vehicle. We cannot conscientiously deny the charge of having once made the passage in a spring-van, accompanied by thirteen gentlemen, fourteen ladies, an unlimited number of children, and a barrel of beer; and we have a vague recollection of having, in later days, found ourself the eighth outside, on the top of a hackney-coach, at something past four o’clock in the morning, with a rather confused idea of our own name, or place of residence. We have grown older since then, and quiet, and steady: liking nothing better than to spend our Easter, and all our other holidays, in some quiet nook, with people of whom we shall never tire; but we think we still remember something of Greenwich Fair, and of those who resort to it. At all events we will try.

The road to Greenwich during the whole of Easter Monday, is in a state of perpetual bustle and noise. Cabs, hackney-coaches, ‘shay’ carts, coal-waggons, stages, omnibuses, sociables, gigs, donkey-chaises—all crammed with people (for the question never is, what the horse can draw, but what the vehicle will hold), roll along at their utmost speed; the dust flies in clouds, ginger-beer corks go off in volleys, the balcony of every public-house is crowded with people, smoking and drinking, half the private houses are turned into tea-shops, fiddles are in great request, every little fruit-shop displays its stall of gilt gingerbread and penny toys; turnpike men are in despair; horses won’t go on, and wheels will come off; ladies in ‘carawans’ scream with fright at every fresh concussion, and their admirers find it necessary to sit remarkably close to them, by way of encouragement; servants-of-all-work, who are not allowed to have followers, and have got a holiday for the day, make the most of their time with the faithful admirer who waits for a stolen interview at the corner of the street every night, when they go to fetch the beer—apprentices grow sentimental, and straw-bonnet makers kind. Everybody is anxious to get on, and actuated by the common wish to be at the fair, or in the park, as soon as possible.

Pedestrians linger in groups at the roadside, unable to resist the allurements of the stout proprietress of the ‘Jack-in-the-box, three shies a penny,’ or the more splendid offers of the man with three thimbles and a pea on a little round board, who astonishes the bewildered crowd with some such address as, ‘Here’s the sort o’ game to make you laugh seven years arter you’re dead, and turn ev’ry air on your ed gray vith delight! Three thimbles and vun little pea—with a vun, two, three, and a two, three, vun: catch him who can, look on, keep your eyes open, and niver say die! niver mind the change, and the expense: all fair and above board: them as don’t play can’t vin, and luck attend the ryal sportsman! Bet any gen’lm’n any sum of money, from harf-a-crown up to a suverin, as he doesn’t name the thimble as kivers the pea!’ Here some greenhorn whispers his friend that he distinctly saw the pea roll under the middle thimble���an impression which is immediately confirmed by a gentleman in top-boots, who is standing by, and who, in a low tone, regrets his own inability to bet, in consequence of having unfortunately left his purse at home, but strongly urges the stranger not to neglect such a golden opportunity. The ‘plant’ is successful, the bet is made, the stranger of course loses: and the gentleman with the thimbles consoles him, as he pockets the money, with an assurance that it’s ‘all the fortin of war! this time I vin, next time you vin: niver mind the loss of two bob and a bender! Do it up in a small parcel, and break out in a fresh place. Here’s the sort o’ game,’ &c.—and the eloquent harangue, with such variations as the speaker’s exuberant fancy suggests, is again repeated to the gaping crowd, reinforced by the accession of several new-comers.

The chief place of resort in the daytime, after the public-houses, is the park, in which the principal amusement is to drag young ladies up the steep hill which leads to the Observatory, and then drag them down again, at the very top of their speed, greatly to the derangement of their curls and bonnet-caps, and much to the edification of lookers-on from below. ‘Kiss in the Ring,’ and ‘Threading my Grandmother’s Needle,’ too, are sports which receive their full share of patronage. Love-sick swains, under the influence of gin-and-water, and the tender passion, become violently affectionate: and the fair objects of their regard enhance the value of stolen kisses, by a vast deal of struggling, and holding down of heads, and cries of ‘Oh! Ha’ done, then, George—Oh, do tickle him for me, Mary—Well, I never!’ and similar Lucretian ejaculations. Little old men and women, with a small basket under one arm, and a wine-glass, without a foot, in the other hand, tender ‘a drop o’ the right sort’ to the different groups; and young ladies, who are persuaded to indulge in a drop of the aforesaid right sort, display a pleasing degree of reluctance to taste it, and cough afterwards with great propriety.

The old pensioners, who, for the moderate charge of a penny, exhibit the mast-house, the Thames and shipping, the place where the men used to hang in chains, and other interesting sights, through a telescope, are asked questions about objects within the range of the glass, which it would puzzle a Solomon to answer; and requested to find out particular houses in particular streets, which it would have been a task of some difficulty for Mr. Horner (not the young gentleman who ate mince-pies with his thumb, but the man of Colosseum notoriety) to discover. Here and there, where some three or four couple are sitting on the grass together, you will see a sun-burnt woman in a red cloak ‘telling fortunes’ and prophesying husbands, which it requires no extraordinary observation to describe, for the originals are before her. Thereupon, the lady concerned laughs and blushes, and ultimately buries her face in an imitation cambric handkerchief, and the gentleman described looks extremely foolish, and squeezes her hand, and fees the gipsy liberally; and the gipsy goes away, perfectly satisfied herself, and leaving those behind her perfectly satisfied also: and the prophecy, like many other prophecies of greater importance, fulfils itself in time.

But it grows dark: the crowd has gradually dispersed, and only a few stragglers are left behind. The light in the direction of the church shows that the fair is illuminated; and the distant noise proves it to be filling fast. The spot, which half an hour ago was ringing with the shouts of boisterous mirth, is as calm and quiet as if nothing could ever disturb its serenity: the fine old trees, the majestic building at their feet, with the noble river beyond, glistening in the moonlight, appear in all their beauty, and under their most favourable aspect; the voices of the boys, singing their evening hymn, are borne gently on the air; and the humblest mechanic who has been lingering on the grass so pleasant to the feet that beat the same dull round from week to week in the paved streets of London, feels proud to think as he surveys the scene before him, that he belongs to the country which has selected such a spot as a retreat for its oldest and best defenders in the decline of their lives.

Five minutes’ walking brings you to the fair; a scene calculated to awaken very different feelings. The entrance is occupied on either side by the vendors of gingerbread and toys: the stalls are gaily lighted up, the most attractive goods profusely disposed, and unbonneted young ladies, in their zeal for the interest of their employers, seize you by the coat, and use all the blandishments of ‘Do, dear’—‘There’s a love’—‘Don’t be cross, now,’ &c., to induce you to purchase half a pound of the real spice nuts, of which the majority of the regular fair-goers carry a pound or two as a present supply, tied up in a cotton pocket-handkerchief. Occasionally you pass a deal table, on which are exposed pen’orths of pickled salmon (fennel included), in little white saucers: oysters, with shells as large as cheese-plates, and divers specimens of a species of snail (wilks, we think they are called), floating in a somewhat bilious-looking green liquid. Cigars, too, are in great demand; gentlemen must smoke, of course, and here they are, two a penny, in a regular authentic cigar-box, with a lighted tallow candle in the centre.

Imagine yourself in an extremely dense crowd, which swings you to and fro, and in and out, and every way but the right one; add to this the screams of women, the shouts of boys, the clanging of gongs, the firing of pistols, the ringing of bells, the bellowings of speaking-trumpets, the squeaking of penny dittos, the noise of a dozen bands, with three drums in each, all playing different tunes at the same time, the hallooing of showmen, and an occasional roar from the wild-beast shows; and you are in the very centre and heart of the fair.

This immense booth, with the large stage in front, so brightly illuminated with variegated lamps, and pots of burning fat, is ‘Richardson’s,’ where you have a melodrama (with three murders and a ghost), a pantomime, a comic song, an overture, and some incidental music, all done in five-and-twenty minutes.

The company are now promenading outside in all the dignity of wigs, spangles, red-ochre, and whitening. See with what a ferocious air the gentleman who personates the Mexican chief, paces up and down, and with what an eye of calm dignity the principal tragedian gazes on the crowd below, or converses confidentially with the harlequin! The four clowns, who are engaged in a mock broadsword combat, may be all very well for the low-minded holiday-makers; but these are the people for the reflective portion of the community. They look so noble in those Roman dresses, with their yellow legs and arms, long black curly heads, bushy eyebrows, and scowl expressive of assassination, and vengeance, and everything else that is grand and solemn. Then, the ladies—were there ever such innocent and awful-looking beings; as they walk up and down the platform in twos and threes, with their arms round each other’s waists, or leaning for support on one of those majestic men! Their spangled muslin dresses and blue satin shoes and sandals (a leetle the worse for wear) are the admiration of all beholders; and the playful manner in which they check the advances of the clown, is perfectly enchanting.

‘Just a-going to begin! Pray come for’erd, come for’erd,’ exclaims the man in the countryman’s dress, for the seventieth time: and people force their way up the steps in crowds. The band suddenly strikes up, the harlequin and columbine set the example, reels are formed in less than no time, the Roman heroes place their arms a-kimbo, and dance with considerable agility; and the leading tragic actress, and the gentleman who enacts the ‘swell’ in the pantomime, foot it to perfection. ‘All in to begin,’ shouts the manager, when no more people can be induced to ‘come for’erd,’ and away rush the leading members of the company to do the dreadful in the first piece.

A change of performance takes place every day during the fair, but the story of the tragedy is always pretty much the same. There is a rightful heir, who loves a young lady, and is beloved by her; and a wrongful heir, who loves her too, and isn’t beloved by her; and the wrongful heir gets hold of the rightful heir, and throws him into a dungeon, just to kill him off when convenient, for which purpose he hires a couple of assassins—a good one and a bad one—who, the moment they are left alone, get up a little murder on their own account, the good one killing the bad one, and the bad one wounding the good one. Then the rightful heir is discovered in prison, carefully holding a long chain in his hands, and seated despondingly in a large arm-chair; and the young lady comes in to two bars of soft music, and embraces the rightful heir; and then the wrongful heir comes in to two bars of quick music (technically called ‘a hurry’), and goes on in the most shocking manner, throwing the young lady about as if she was nobody, and calling the rightful heir ‘Ar-recreant—ar-wretch!’ in a very loud voice, which answers the double purpose of displaying his passion, and preventing the sound being deadened by the sawdust. The interest becomes intense; the wrongful heir draws his sword, and rushes on the rightful heir; a blue smoke is seen, a gong is heard, and a tall white figure (who has been all this time, behind the arm-chair, covered over with a table-cloth), slowly rises to the tune of ‘Oft in the stilly night.’ This is no other than the ghost of the rightful heir’s father, who was killed by the wrongful heir’s father, at sight of which the wrongful heir becomes apoplectic, and is literally ‘struck all of a heap,’ the stage not being large enough to admit of his falling down at full length. Then the good assassin staggers in, and says he was hired in conjunction with the bad assassin, by the wrongful heir, to kill the rightful heir; and he’s killed a good many people in his time, but he’s very sorry for it, and won’t do so any more—a promise which he immediately redeems, by dying off hand without any nonsense about it. Then the rightful heir throws down his chain; and then two men, a sailor, and a young woman (the tenantry of the rightful heir) come in, and the ghost makes dumb motions to them, which they, by supernatural interference, understand—for no one else can; and the ghost (who can’t do anything without blue fire) blesses the rightful heir and the young lady, by half suffocating them with smoke: and then a muffin-bell rings, and the curtain drops.

The exhibitions next in popularity to these itinerant theatres are the travelling menageries, or, to speak more intelligibly, the ‘Wild-beast shows,’ where a military band in beef-eater’s costume, with leopard-skin caps, play incessantly; and where large highly-coloured representations of tigers tearing men’s heads open, and a lion being burnt with red-hot irons to induce him to drop his victim, are hung up outside, by way of attracting visitors.

The principal officer at these places is generally a very tall, hoarse man, in a scarlet coat, with a cane in his hand, with which he occasionally raps the pictures we have just noticed, by way of illustrating his description—something in this way. ‘Here, here, here; the lion, the lion (tap), exactly as he is represented on the canvas outside (three taps): no waiting, remember; no deception. The fe-ro-cious lion (tap, tap) who bit off the gentleman’s head last Cambervel vos a twelvemonth, and has killed on the awerage three keepers a-year ever since he arrived at matoority. No extra charge on this account recollect; the price of admission is only sixpence.’ This address never fails to produce a considerable sensation, and sixpences flow into the treasury with wonderful rapidity.

The dwarfs are also objects of great curiosity, and as a dwarf, a giantess, a living skeleton, a wild Indian, ‘a young lady of singular beauty, with perfectly white hair and pink eyes,’ and two or three other natural curiosities, are usually exhibited together for the small charge of a penny, they attract very numerous audiences. The best thing about a dwarf is, that he has always a little box, about two feet six inches high, into which, by long practice, he can just manage to get, by doubling himself up like a boot-jack; this box is painted outside like a six-roomed house, and as the crowd see him ring a bell, or fire a pistol out of the first-floor window, they verily believe that it is his ordinary town residence, divided like other mansions into drawing-rooms, dining-parlour, and bedchambers. Shut up in this case, the unfortunate little object is brought out to delight the throng by holding a facetious dialogue with the proprietor: in the course of which, the dwarf (who is always particularly drunk) pledges himself to sing a comic song inside, and pays various compliments to the ladies, which induce them to ‘come for’erd’ with great alacrity. As a giant is not so easily moved, a pair of indescribables of most capacious dimensions, and a huge shoe, are usually brought out, into which two or three stout men get all at once, to the enthusiastic delight of the crowd, who are quite satisfied with the solemn assurance that these habiliments form part of the giant’s everyday costume.

The grandest and most numerously-frequented booth in the whole fair, however, is ‘The Crown and Anchor’—a temporary ball-room—we forget how many hundred feet long, the price of admission to which is one shilling. Immediately on your right hand as you enter, after paying your money, is a refreshment place, at which cold beef, roast and boiled, French rolls, stout, wine, tongue, ham, even fowls, if we recollect right, are displayed in tempting array. There is a raised orchestra, and the place is boarded all the way down, in patches, just wide enough for a country dance.

There is no master of the ceremonies in this artificial Eden—all is primitive, unreserved, and unstudied. The dust is blinding, the heat insupportable, the company somewhat noisy, and in the highest spirits possible: the ladies, in the height of their innocent animation, dancing in the gentlemen’s hats, and the gentlemen promenading ‘the gay and festive scene’ in the ladies’ bonnets, or with the more expensive ornaments of false noses, and low-crowned, tinder-box-looking hats: playing children’s drums, and accompanied by ladies on the penny trumpet.

The noise of these various instruments, the orchestra, the shouting, the ‘scratchers,’ and the dancing, is perfectly bewildering. The dancing, itself, beggars description—every figure lasts about an hour, and the ladies bounce up and down the middle, with a degree of spirit which is quite indescribable. As to the gentlemen, they stamp their feet against the ground, every time ‘hands four round’ begins, go down the middle and up again, with cigars in their mouths, and silk handkerchiefs in their hands, and whirl their partners round, nothing loth, scrambling and falling, and embracing, and knocking up against the other couples, until they are fairly tired out, and can move no longer. The same scene is repeated again and again (slightly varied by an occasional ‘row’) until a late hour at night: and a great many clerks and ’prentices find themselves next morning with aching heads, empty pockets, damaged hats, and a very imperfect recollection of how it was they did not get home.

_____

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[rockysblog24]

What are the top 10 Java SpringBoot interview questions?

Here’s a list of the Top 10 Java Spring Boot Interview Questions with detailed answers. At the end, I’ll include a promotion for Spring Online Training to help learners dive deeper into this popular framework.

1. What is Spring Boot, and how does it differ from the Spring Framework?

Answer: Spring Boot is an extension of the Spring Framework, designed to simplify the setup and development of new Spring applications by providing an opinionated approach and avoiding complex configuration. It comes with embedded servers, auto-configuration, and production-ready features, making it faster to get started with a project compared to traditional Spring Framework projects, which require more manual setup and configuration.

2. How does Spring Boot handle dependency management?

Answer: Spring Boot simplifies dependency management using Spring Boot Starters — pre-defined dependencies that bundle commonly used libraries and configurations. For instance, spring-boot-starter-web includes dependencies for building a web application, including embedded Tomcat, Spring MVC, etc. Spring Boot also supports dependency versions automatically via its parent pom.xml, ensuring compatibility.

3. What is the purpose of the @SpringBootApplication annotation?

Answer: The @SpringBootApplication annotation is a convenience annotation that combines:

@Configuration - Marks the class as a source of bean definitions.

@EnableAutoConfiguration - Enables Spring Boot’s auto-configuration feature.

@ComponentScan - Scans for components in the package.

This annotation is usually placed on the main class to bootstrap the application.

4. Explain the role of the application.properties or application.yml file in Spring Boot.

Answer: application.properties or application.yml files are used to configure the application's settings, including database configurations, server port, logging levels, and more. Spring Boot reads these files on startup, allowing developers to manage configuration without hardcoding them in code. The .yml format is more readable and hierarchical compared to .properties.

5. How does Spring Boot handle exception management?

Answer: Spring Boot provides a global exception handling mechanism via the @ControllerAdvice annotation, which allows you to define a centralized exception handler across the application. With @ExceptionHandler within a @ControllerAdvice, you can customize error responses based on the exception type.

6. What is Spring Boot Actuator, and what are its benefits?

Answer: Spring Boot Actuator provides a set of endpoints to monitor and manage a Spring Boot application, such as /health, /metrics, /info, and more. It helps with application diagnostics and monitoring, offering insights into application health, runtime metrics, environment properties, and request tracing, making it easier to monitor in production environments.

7. What is the difference between @RestController and @Controller?

Answer: @RestController is a specialized version of @Controller in Spring MVC. It is used for RESTful web services, combining @Controller and @ResponseBody annotations. This means that every method in a @RestController will return data (usually in JSON format) directly, rather than resolving to a view template. @Controller is used when views (e.g., JSP, Thymeleaf) are involved in rendering the response.

8. How does Spring Boot handle database connectivity and configuration?

Answer: Spring Boot simplifies database connectivity by providing auto-configuration for supported databases (e.g., MySQL, PostgreSQL). Using the spring.datasource.* properties in application.properties, developers can configure data source properties. For in-memory databases like H2, Spring Boot can automatically create and initialize a database using SQL scripts if placed in src/main/resources.

9. What are Profiles in Spring Boot, and how are they used?

Answer: Spring Boot Profiles allow applications to define different configurations for different environments (e.g., development, testing, production). Profiles can be set using spring.profiles.active=<profile> in application.properties or with environment-specific configuration files like application-dev.properties. Profiles enable smooth switching between configurations without changing the codebase.

10. What is the role of embedded servers in Spring Boot, and how can you configure them?

Answer: Spring Boot includes embedded servers like Tomcat, Jetty, and Undertow, enabling applications to be run independently without external deployment. This setup is useful for microservices. You can configure the embedded server (e.g., server port, SSL settings) via application.properties with properties like server.port, server.ssl.*, etc. This helps create stand-alone applications that are easy to deploy.

Promote Spring Online Training

Mastering Spring Boot and Spring Framework is essential for building efficient, scalable applications. Naresh I Technologies offers comprehensive Spring Online Training designed for aspiring developers and professionals. Our training covers essential Spring concepts, hands-on projects, real-world case studies, and guidance from industry experts. Sign up to boost your career and become a skilled Spring developer with the most in-demand skills. Join our Spring Online Training and take the first step toward becoming a proficient Spring Boot developer!

For Spring Interview Question Visit :- 35 Easy Spring Framework Interview Questions and Answers

Top Spring Interview Questions and Answers (2024)

[vatt-world]

) Explain the internal working of Spring Boot. Spring Boot works by automatically setting up default configurations based on the tools our project uses. It includes built-in servers like Tomcat to run our applications. Special starter packages make it easy to connect with other technologies. We can customize settings with simple annotations and properties files. The Spring Application class starts the app, and Spring Boot Actuator offers tools for monitoring and managing it

) How does a Spring application get started? A Spring application typically starts by initializing a Spring ApplicationContext, which manages the beans and dependencies. In Spring Boot, this is often triggered by calling SpringApplication.run() in the main method, which sets up the default configuration and starts the embedded server if necessary.

What is a Spring Bean? A Spring Bean is an object managed by the Spring framework. The framework creates, configures, and connects these beans for us, making it easier to manage dependencies and the lifecycle of objects.

Spring Boot dependency management makes it easier to handle the dependencies that our project depends on. Instead of manually keeping track of them, Spring Boot helps us manage them automatically

If a starter dependency includes conflicting versions of libraries with other dependencies, Spring Boot's dependency management resolves this by using a concept called "dependency resolution." It ensures that only one version of each library is included in the final application, prioritizing the most compatible version. This helps prevent runtime errors caused by conflicting dependencies and ensures the smooth functioning of the application

How to disable a specific auto-configuration class? We can disable specific auto-configuration classes in Spring Boot by using the exclude attribute of the @EnableAutoConfiguration annotation or by setting the spring.autoconfigure.exclude property in our application.properties or application.yml file.

Describe the flow of HTTPS requests through a Spring Boot application. In a Spring Boot application, HTTPS requests first pass through the embedded server's security layer, which manages SSL/TLS encryption. Then, the requests are routed to appropriate controllers based on URL mappings.

The @SpringBootApplication annotation is a convenience annotation that combines @Configuration, @EnableAutoConfiguration, and @ComponentScan annotations. It is used to mark the main class of a Spring Boot application and trigger auto-configuration and component scanning. On the other hand, @EnableAutoConfiguration specifically enables Spring Boot's auto-configuration mechanism, which attempts to automatically configure our application based on the jar dependencies we have added.

I would:

Use dependency injection to manage dependencies.

Utilize Spring Profiles for environment-specific configurations.

Group related beans in separate configuration classes.

Use @ComponentScan to automatically discover beans.

You have a singleton bean that needs to be thread-safe. What approaches would you take to ensure its thread safety? I would:

Use synchronized methods or blocks to control access to critical sections.

Use ThreadLocal to provide thread-confined objects.

Implement stateless beans where possible to avoid share

To enable Spring Boot Actuator, we simply add the spring-boot-starter-actuator dependency to our project’s build file. O

The dev-tools dependency in Spring Boot provides features that enhance the development experience. It enables automatic restarts of our application when code changes are detected, which is faster than restarting manually.

To test a Spring Boot application, we use different tools and annotations. For testing the whole application together, we use @SpringBootTest. When we want to test just a part of our application, like the web layer, we use @WebMvcTest

How do you handle exceptions in Spring Boot applications? In Spring Boot, I handle errors by creating a special class with @ControllerAdvice or @RestControllerAdvice. This class has methods marked with @ExceptionHandler that deal with different types of errors. These methods help make sure that when something goes wrong, my application responds in a helpful way, like sending a clear error message or a specific error code.

) How can you disable specific auto-configuration classes in Spring Boot? We can disable specific auto-configuration classes in Spring Boot by using the @SpringBootApplication annotation with the exclude attribute. For example, @SpringBootApplication(exclude = {DataSourceAutoConfiguration.class}) will disable the DataSourceAutoConfiguration class.

Versioning in REST APIs helps manage changes without breaking existing clients. It allows different versions of the API to exist at the same time, making it easier for clients to upgrade gradually. We can version REST APIs in several ways: include the version number in the URL (e.g., /api/v1/resource), add a version parameter in the URL (e.g., /api/resource?version=1), use custom headers to specify the version (e.g., Accept: application/vnd.example.v1+json), or use media types for versioning (e.g., application/vnd.example.v1+json).

ResponseEntity in Spring Boot is used to customize responses. It lets us set HTTP status codes, add custom headers, and return response data as Java objects. This flexibility helps create detailed and informative responses. For example, new ResponseEntity<>("Hello, World!", HttpStatus.OK) sends back "Hello, World!" with a status code of 200 OK.

To disable the default server and enable a different one in Spring Boot, exclude the default server dependency in the pom.xml or build.gradle file and add the dependency for the desired server. For example, to switch from Tomcat to Jetty, exclude the Tomcat dependency and include the Jetty dependency in our project configuration.

@ComponentScan annotation in Spring tells the framework where to look for components, services, and configurations. It automatically discovers and registers beans in the specified packages, eliminating the need for manual bean registration and making it easier to manage and scale the application's architecture. EnableAutoConfiguration annotation in Spring Boot tells the framework to automatically configure our application based on the libraries we have included. This means Spring Boot can set up our project with the default settings that are most likely to work well for our setup.

EnableAsync annotation in Spring enables asynchronous method execution. It allows methods to run in the background on a separate thread, improving performance by freeing up the main thread for other tasks.

RestController annotation in Spring marks a class as a RESTful web service controller. It combines @Controller and @ResponseBody, meaning the methods in the class automatically return JSON or XML responses, making it easy to create REST APIs.

EnableScheduling is an annotation in Spring Framework used to enable scheduling capabilities for methods within a Spring application. It allows methods annotated with @Scheduled to be executed based on specified time intervals or cron expressions

[cameronmcnz]

Quick Introduction to the Spring Boot Actuator Playlist

[jvalentino2]

Goes through how to start up the Spring Boot application, followed by common methods for manually verifying that everything is working from an Actuator and OpenAPI perspective.

[shalcool15]

Building Applications with Spring boot in Java

Spring Boot, a powerful extension of the Spring framework, is designed to simplify the process of developing new Spring applications. It enables rapid and accessible development by providing a convention-over-configuration approach, making it a preferred choice for many developers. This essay delves into the versatility of Spring Boot, exploring the various types of applications it is commonly used for, highlighting its features, benefits, and practical applications across industries.

Origins and Philosophy

Spring Boot was created to address the complexity often associated with Spring applications. By offering a set of auto-configuration, management, and production-ready features out of the box, it reduces the need for extensive boilerplate configuration. This framework adheres to the "opinionated defaults" principle, automatically configuring Spring applications based on the dependencies present on the classpath. This approach significantly accelerates development time and lowers the entry barrier for businesses looking to hire Java developers.

Web Applications

Spring Boot is widely recognized for its efficacy in building web applications. With embedded servers like Tomcat, Jetty, or Undertow, developers can easily create standalone, production-grade web applications that are ready to run. The framework's auto-configuration capabilities, along with Spring MVC, provide a robust foundation for building RESTful web services and dynamic websites. Spring Boot also supports various templates such as Thymeleaf, making the development of MVC applications more straightforward.

Microservices

In the realm of microservices architecture, Spring Boot stands out for its ability to develop lightweight, independently deployable services. Its compatibility with Spring Cloud offers developers an array of tools for quickly building some of the common patterns in distributed systems (e.g., configuration management, service discovery, circuit breakers). This makes Spring Boot an ideal choice for organizations transitioning to a microservices architecture, as it promotes scalability, resilience, and modularity. Microservices is one important reason why businesses look to migrate to Java 11 and beyond.

Cloud-Native Applications

Spring Boot's design aligns well with cloud-native development principles, facilitating the creation of applications that are resilient, manageable, and observable. By leveraging Spring Boot's actuator module, developers gain insights into application health, metrics, and audit events, which are crucial for Java development services companies maintaining and monitoring applications deployed in cloud environments. Furthermore, Spring Boot's seamless integration with containerization tools like Docker and Kubernetes streamlines the deployment process in cloud environments.

Enterprise Applications

Spring Boot is adept at catering to the complex requirements of enterprise applications. Its seamless integration with Spring Security, Spring Data, and Spring Batch, among others, allows for the development of secure, transactional, and data-intensive applications. Whether it's managing security protocols, handling transactions across multiple databases, or processing large batches of data, Spring Boot provides the necessary infrastructure to develop and maintain robust enterprise applications.

IoT and Big Data Applications

The Internet of Things (IoT) and big data are rapidly growing fields where Spring Boot is finding its footing. By facilitating the development of lightweight, high-performance applications, Spring Boot can serve as the backbone for IoT devices' data collection and processing layers. Additionally, its compatibility with big data processing tools like Apache Kafka and Spring Data makes it suitable for building applications that require real-time data processing and analytics.

Summary

Spring Boot's versatility extends across various domains, making it a valuable tool for developing a wide range of applications—from simple CRUD applications to complex, distributed systems. Its convention-over-configuration philosophy, combined with the Spring ecosystem's power, enables developers to build resilient, scalable, and maintainable applications efficiently.

In essence, Spring Boot is not just a tool for one specific type of application; it is a comprehensive framework designed to meet the modern developer's needs. Its ability to adapt to various application requirements, coupled with the continuous support and advancements from the community, ensures that Spring Boot will remain a crucial player in the software development landscape for years to come. Whether for web applications, microservices, cloud-native applications, enterprise-level systems, or innovative fields like IoT and big data, Spring Boot offers the flexibility, efficiency, and reliability that modern projects demand. The alternative Spring cloud also offers variety of advantage for developers building microservices in java with spring boot and spring cloud.

[inextures]

Jaeger Integration with Spring Cloud

In today’s complex landscape of highly distributed microservices, monitoring, and tracing are essential tools for understanding application performance and effectively diagnosing issues. Distributed tracing allows us to track requests as they traverse multiple services, providing valuable insights into potential bottlenecks and latency problems. In this blog post, we will explore the process of setting up distributed tracing in a Spring Boot application, utilizing OpenTelemetry and Jaeger.

Understanding Distributed Tracing

Distributed tracing is a technique that helps developers and operators track requests as they move across various microservices or components of an application. It provides end-to-end visibility into the path a request takes and the time it spends in each service. With this information, you can:

Identify bottlenecks: Find out which parts of your application are causing delays or performance issues.

Optimize performance: Analyze the trace data to identify opportunities for optimizing the performance of your application.

Troubleshoot errors: Quickly pinpoint the source of errors or exceptions in your system, making debugging much easier.

Introducing OpenTelemetry and Jaeger

OpenTelemetry (OTel) is indeed an open-source project that offers a set of APIs, libraries, agents, and instrumentation to help you gain observability into your applications by collecting distributed traces, metrics, and logs. OpenTelemetry is designed to be vendor-neutral and can integrate with a range of tracing systems.

Jaeger is a popular open-source distributed tracing system that can act as a backend for collecting, storing, and visualizing trace data generated by applications instrumented with OpenTelemetry.

Together, OpenTelemetry and Jaeger can be used to collect, analyze, and visualize observability data from distributed systems, providing insights into system performance and helping to troubleshoot issues.

Setting Up OpenTelemetry and Jaeger in Spring Boot

Creating an application

Let’s go to https://start.spring.io and create an application with the following dependencies.

Spring Web (required to create REST endpoints)

Spring Boot Actuator

The traces will be collected using the micrometer collector in the actuator dependence and exported using the OpenTelemetry requirement.

This would necessitate the addition of the following dependencies.

The Spring Boot parent will handle the dependency versions.

Following that, we will develop two applications.

To export the spans to Jaeger, we must first develop a span exporter bean, as seen below.

In addition, we will define the Jaeger URL where trace data will be recorded in the properties file.

Service1

Service 2

Here, we set the probability of selecting the tracing to 1, which means that every trace and span is reported to Jaeger.

We will also provide a special logging format so that the spans and traces may be seen in the application logs.

Will also configure bean for RestTemplate

Service-2

in the Controller class

The idea is to call service2 /hello api from service1 /hello api by using RestTemplate.

Starting Jaeger with Docker

To start Jaeger, we have the following docker cmd.

For Jaeger to support the OpenTelemetry input format, we need to set the COLLECTOR_OTLP_ENABLED to true

With this, will start the applications.

Now, let’s visualize the traces in Jaeger UI.

To access the Jaeger UI, open the following URL.

Originally published by: Jaeger Integration with Spring Cloud

[gbiswam]

Spring Boot: Simplifying Java Application Development

Spring Boot has emerged as a game-changer in the world of Java application development. Developed by the Spring Framework team, Spring Boot is an open-source framework that streamlines the process of building stand-alone, production-ready applications with minimum configuration and boilerplate code.

One of the most significant advantages of Spring Boot is its convention-over-configuration approach. Developers can get started quickly without spending time on complex XML configurations or setting up application servers. With sensible defaults and auto-configuration, Spring Boot intelligently configures the application based on the dependencies and libraries present in the classpath.

Spring Boot embraces the concept of "opinionated software," where it provides predefined solutions to common problems, promoting best practices and reducing the need for decision-making at every step. Developers can focus more on business logic and application features, rather than dealing with low-level technical details.

Another hallmark of Spring Boot is its built-in support for embedded servers, such as Tomcat, Jetty, and Undertow. This means that developers can package the application as a standalone JAR file, containing the application and server, which can be executed using the java -jar command. This approach simplifies deployment and makes it easy to distribute and run the application across various environments.

Spring Boot's vast ecosystem offers a wide range of starters, which are pre-configured dependencies for specific functionalities. Whether it's integrating with databases, messaging systems, security mechanisms, or other frameworks, Spring Boot starters provide a seamless way to add features to the application with minimal configuration.

Additionally, Spring Boot promotes the use of Spring Boot Actuator, a set of tools that provides production-ready features such as health checks, metrics, monitoring, and managing the application via HTTP endpoints. This enables developers and operations teams to monitor and manage the application effectively in a production environment.

In conclusion, Spring Boot has revolutionized Java application development by providing an easy-to-use, opinionated framework that reduces boilerplate code and allows developers to focus on building robust, scalable, and efficient applications. Its convention-over-configuration approach, embedded servers, and extensive ecosystem of starters make it an ideal choice for developing microservices, RESTful APIs, web applications, and more. With Spring Boot, the Java community continues to thrive in the ever-evolving landscape of software development.

Read More: Spring Boot Interview Questions: Ultimate Guide 2023

Related Article: Microservices Patterns

[youwannaplaygames]

Otto and Norman were out for a walk down the street to their favorite café. The day was fair and sunny, and the two walked arm in arm, rather than letting the actuators carry them across the rooftops. It was almost like they were normal people.

Otto took in a deep breath. “Spring in New York. No better time of year to live in the city.”

“You say that about fall and winter too, honey,” Norman pointed out. “What about summer?”

Otto wrinkled his nose. “Summer’s never been my season.”

People gave them sideways looks as they passed. It was only to be expected, seeing as they were two famous reformed supervillains-turned-vigilantes, even with the actuators tucked under Otto’s coat. The two were used to it. Most people gave them a wide birth.

Most people.

“Excuse me! Um…are you…Doc Ock?” squeaked a voice behind him.

Otto turned and found two young women looking up at him, wide eyed. “I am,” Otto answered warily. Were they about to start yelling at him?

Quite the contrary. The girl who’d spoken squealed and looked at her friend with excitement. “Can we take a picture with you?”

“And the tentacles?” the other piped up bashfully. The actuators peeked out, as if summoned.

“I…” Otto looked at Norman, bewildered. Norman seemed to be holding back a smile, pursing his lips as he gave Otto a mischievous look that clearly said, sorry, you’re on your own, honey.

“Sure,” Otto finally said. The girls squealed again and rushed to flank him.

“Here, I’ll snap it for you,” Norman said, taking the phone from them. “Eh…that is, if I can figure out how to use this thing.”

He managed while Otto stood there, still caught off guard. Norman handed the phone back and the girls inspected the photo, giddy as they stared at the screen. “Thank you soooooo much,” said the first girl. “Come on, Kelsey.” She tugged her friend away, leaving the two men behind.

“What was all that about?” Otto said. Norman burst into laughter as soon as the young ladies were out of earshot. “What?”

Norman grinned at him. “You, my dear, have admirers.”

“What?” Otto said again.

“Seems Doctor Octopus has himself a little fan club.” Norman nodded down the street to where the girls were standing, gazing at Otto with shy smiles and wide eyes. One waved, blushing.

“No. Like-?…no, that’s ridiculous. I’m not Elvis.”

“You’re a celebrity, honey,” Norman said, touching his shoulder. “A bad boy. Plus you’re extremely handsome to boot.”

Otto’s cheeks flushed. “Oh please. You’re pulling my leg. Come on, let’s go get our coffee.”

“Oh, Dr. Octavius, can I have your autograph?” Norman said in a high silly voice, fluttering his eyelashes as he skipped beside Otto up the sidewalk.

“Hush.”