Spring Boot Practice Test

Spring Boot Framework

Spring Boot Tutorial

Spring Boot is a microservice-based Java web framework that is open source. The Spring Boot framework delivers a completely customizable and fully production-ready environment with its prebuilt code. Developers can create a fully enclosed application with embedded application servers using the microservice architecture. It is a lightweight and reactive framework that works to build high-performance and fast web applications.

Spring Boot is a Java implementation of the concepts and approaches of reactive programming. The Spring Framework has been uboot-microservicesramming since version 2. x, was introduced in 2004, and has been used to deliver incremental feedback on the server. Spring Boot was created so developers can start creating reactive applications without having to learn or configure the Spring Framework or other components that use its reactive features.

Spring Boot is a lightweight and reactive web application development framework that makes microservices development easier and faster. Spring Boot’s features include support for guaranteed application delivery, multi-datacenter resilience, security, monitoring, and debugging.
The Spring Framework is part of the open-source “Spring Project” at the Software Engineering Institute at Carnegie Mellon University in Pittsburgh, Pennsylvania. It was created by Rod Johnson and is now maintained by active developers worldwide.

Free Spring Boot Practice Online Test

Cascading failures in Spring Boot microservice

Cascading failure is a process in which the failure of one or a few interconnected parts can cause the failure of other others, and so on. Cascading failures are common in large-scale enterprise applications, which can be difficult to troubleshoot and resolve. Cascading failures are often difficult to test for and even harder to prevent. The cascading failure in a typical Spring Boot architecture consists of two major parts:
1. Persistence layer: If the persistence layer fails, it can take down the entire app. It can be for various reasons, such as I/O errors, network problems, or disk space issues.
2. Service layer: If the service layer fails, it can take down other connected microservices. These expose all service classes to potential failures and make them unreliable.

Cascading failures are hard to test because they can occur in many places of an application at once.

Spring boot e-commerce ultimate course

The Spring Boot E-Commerce Ultimate Course is a thorough course that teaches you how to use Spring Boot to create a successful eCommerce business. You’ll learn how to build and implement an online store, publish the app to a web server, and manage customer data. This course is for experienced developers who have worked with Java and Spring Boot before. A web server and Java must be installed on your computer, and a basic understanding of web design and development. These courses can be taken online through a convenient, interactive learning path. You’ll work through the course’s lessons and exercises in your own time, at your own pace. Your technical experts verify the course for content, duration, and quality.

Spring Boot one to one unidirectional

A one-to-one mapping is a relationship between two persistent objects related to each other. It becomes unidirectional if one persistence object utilizes another and the other does not use the first persistence object. It becomes bidirectional if one persistence object utilizes another and the other uses the first persistence object. A unidirectional one-to-one mapping is a relationship between two persistent objects related to each other. It becomes unidirectional if one persistence object utilizes another and the other does not use the first persistence object. It becomes bidirectional if one persistence object utilizes another and the other uses the first persistence object. A unidirectional one-to-one mapping is a relationship between two persistent objects related to each other. It becomes unidirectional if one persistence object utilizes another and the other does not use the first persistence object.

Spring Boot starter parent

Spring Boot Starter Parent is a starter project that offers the spring-based application’s default settings. In the pom.xml file, it is inserted as a parent. Spring-boot-dependencies is the parent of spring-boot-starter-parent. Spring-boot-starter-parent inherits spring-boot-dependencies’ dependency management. Spring Boot included a bootstrap starter parent. The parent of spring-boot-starter-parent is a starter project that offers the spring-based application’s default settings. In the pom.xml file, it is inserted as a parent. Spring-boot-dependencies is the parent of spring-boot-starter-parent. Spring-boot-starter-parent inherits spring-boot dependency management.

Spring Boot classpath

The classpath is an important and very special feature of Spring Boot. It determines where a program’s classes are located on your computer. A classpath has three parts:

1. The location of the main class file
2. The location of other .class files
3. The location of any resources that include a .class file

The classpath is an important and very special feature of Spring Boot. It determines where a program’s classes are located on your computer.

Configure Spring Boot port

The Spring Boot autoconfiguration represents a method of automatically configuring a Spring application based on the classpath dependencies. It can simplify development by removing the need to define some beans part of the auto-configuration classes.
An XML file containing class information is called a Spring configuration file. It explains how those classes are set up and introduced to one another. On the other hand, the XML configuration files are more lengthy and organized. It becomes extremely difficult to handle large projects if it is not properly planned and written.

How to change Tomcat port in Spring Boot?

You may modify the Tomcat Server Port in a Spring Boot application in two ways:

1. Using application.properties
2. Using Java code

A. Alter the Port Using the application.properties property
Spring Boot introduced the “application.properties” file, which is located in the “src/main/resources” directory and is automatically identified without the need for any spring-based customizations. The application.properties file contains a list of properties that can be changed through the application configuration. It also allows different values for properties that are not mandatory and vice versa. The value of each property can be expressed as a list of characters, including alphanumeric characters, digits, a special character ‘=,’ and underscores (‘_’).

application.properties
server.port = 1299

If you start the program, the tomcat server will take 1299 as its port number, which you can check in the console and then run the application on.

B. Alter the Port Using Java Code
In reality, if you are using Tomcat in the production environment, it is recommended to rewrite the port number in the configuration file of Tomcat. You can also change your port number using Java code instead of the application.properties. It restructures a spring boot application into a web application, which will allow you to use a fixed port number instead of randomly generating numbers. The following example displays how Tomcat’s Port Number can be set using Java code:

public String getTomcatHost() {
try {
Port port = (new InetSocketAddress(9999)).getLocalPort();
return “localhost:” + port.

Spring Boot Test

Master Spring boot-microservices with CQRS and event sourcing

Master Spring Boot Microservices with CQRS & Event Sourcing is a published training course for developing microservices using the Spring Boot framework. Spring Boot is an open-source platform for developing microservices and Spring-ready applications based on the Java programming language. This project-based training course will teach you to create a strong application utilizing CQRS and Event Sourcing software development templates. During this course, you will learn the latest best practices for event sourcing with Spring Boot and the ultra-low latency of CQRS. This course is designed for people with a basic understanding of Java, Spring Boot, and RESTful API development.
The first part of the class teaches you about Spring Boot fundamentals, including application architecture, programming languages, and basic concepts discussed in previous Microservices training courses. The second section introduces CQRS & Event Sourcing which explains how a microservice architecture can be built using this pattern that removes the need to re-invent the wheel and provides better communication between teams. This part then focuses on Domain-Driven Design (DDD), which is used to create a reactive and event-driven API.

Multiple Request Mapping Spring Boot

From the @RequestMapping annotation of Spring MVC controller can make use of any other request path defined in the application configuration file and automatically map requests across multiple controllers in the same application. Request paths are used to identify representations and resources required by an application’s end-users. A request mapping is the mapping of a request to a controller action.

Spring Boot controller prefix

In the application, you can provide the controller’s prefix. inside each controller, properties file with the prefix key
For example:
spring-boot.controller.prefix=foobarController

foobarController is a Spring MVC controller that inherits DataController & FoobarController. As mentioned above, within controllers, you can use @RequestMapping to define request paths for your application and automatically map requests across multiple controllers in the same application. Request paths are used to identify representations and resources required by an application’s end-users.
The following code illustrates this:

<beans:bean id=”controller”
class=”org.springframework.boot.autoconfigure.mvc5.data.

What is DAO class in Spring Boot?

The acronym DAO refers to a data access object. The DAO class is usually in charge of two concepts. Providing a CRUD interface for a single entity while encapsulating the persistent layer’s details. DAO implementation should be thread-safe, but the SQL statements used should be optimized to use a minimum of resources and avoid blocking threads.
There are two ways to create DAO classes. Using annotation or XML configuration. DAO classes can also exist independently of any controller.
DAO (Data Access Object) class is responsible for database mapping and does not contain business logic. It comes under the package name “com.packtpub”.”projectname”.”model”, where “projectname” is the name of your project that you created in the Spring Boot application and “model” represents the individual table for which it is responsible for providing CRUD capabilities.

Spring Boot and Dropwizard

Spring Boot is a framework created by “The Spring Team” to make launching and developing new Spring Applications easier. It includes default code and annotation configuration to help you quickly get started with new Spring projects. It uses an approach called “Opinionated Defaults Configuration” to minimize boilerplate code and configuration to improve the Development, Unit Test, and Integration Test processes. For example, in a web application, your controllers are automatically mapped to Controller classes annotated with @RestController.
Dropwizard is an open-source Java framework for creating REST APIs quickly. Dropwizard is an ecosystem that bundles all dependencies (such as Jersey, Jackson, or Jetty) into a single package or can be added as a separate module. It is an open-source framework used by Spring Boot and Spring Cloud.
The main idea is to offer a simple and fast solution to create REST APIs. Dropwizard has pain-free integration with other frameworks such as Spring Boot, Netty, and Hibernate.

Spring Boot auth filter

Spring Boot has a concept of an Authentication Filter that is used to authenticate a user using the UserDetailsService. An Authentication Filter Object is an object that transforms a user into and out of a valid username/password combination.
The following code helps us to create an authentication filter.

@SpringBootApplication public class AuthFilterExample {
@Autowired private UserDetailsService userDetailsService;
@Bean(name = “auth-filter”) public AuthFilter authFilter() {
return new AuthFilter();
} }

Spring Boot Questions and Answers

Spring Boot is a microservice-based Java web framework that is open source. The Spring Boot framework delivers a completely customizable and fully production-ready environment with its prebuilt code.

  • In pom.xml, add a dependency for your database connector.
  • Delete the H2 Dependency from the pom.xml file. 
  • Create a My SQL Database 
  • Establish a link to your database. 
  • Restart, and you’re all set!

We may use the spring-boot-starter-jetty starter to use Jetty in our Spring Boot application. Spring Boot bundles Tomcat and Jetty dependencies as distinct starters to make this process as simple as possible. In your pom.xml file, include the spring-boot-starter-jetty starter.

Open the Services tool window in your Spring Boot application: Press Alt+8 or select View | Tool Windows | Services. Open the Endpoints tab in your running Spring Boot application.

Spring Boot is a tech stack tool in the Frameworks (Full Stack) area. Spring Boot is an open-source project with 61.2K stars on GitHub and 36.4K forks.

Java Spring Boot (Spring Boot) is a solution that uses three basic capabilities to help develop web applications and microservices with Spring Framework faster and easier: Autoconfiguration. Configuration with a point of view. Ability to develop standalone applications

A Spring Boot application’s foundation is ApplicationContext. It is responsible for instantiating, configuring, and assembling the beans and represents the Spring IoC container. Reading configuration metadata provides the container with instructions on which objects to instantiate, configure, and assemble.

HikariCP is a high-performance JDBC connection pool that is dependable. Compared to other connection pool APIs, it is much faster, lighter, and has higher performance. HikariCP is currently the default pool implementation in Spring Boot 2 due to these convincing reasons.

Spring Boot enables programmers to construct apps that just run. By embedding a web server like Tomcat or Netty within your program during the initialization phase, you may construct independent applications that function without an external web server.

When you need to arrange values in ad hoc structures for sending data around, a DTO comes in handy. DTOs are a solution that is extremely near to perfection in terms of design. DTOs aid in separating presentation from the service layer and domain model.

It allows you to configure Java Beans, XML settings, and Database Transactions customizable. It maintains REST endpoints and offers robust batch processing. Everything is auto-configured in Spring Boot; no human configuration is required.

Spring Boot Actuator is a Spring Boot Framework sub-project. It exposes operational information about any running application via HTTP endpoints. The key advantage of this library is that it provides us with health and monitoring information from production-ready apps.

Eureka Server is a software application that keeps track of all client-service apps. Each Microservice will register with Eureka, and Eureka will be aware of all client applications operating on each port and IP address.

The controller class in Spring Boot handles incoming REST API calls, constructs a model, and returns the view to be shown as a response. The @Controller or @RestController annotations annotate the controller classes in Spring.

Spring MVC is a Spring framework component that aids in the management of HTTP requests and answers. On the other hand, Spring Boot is a Spring framework extension that makes it easier to construct apps.

Spring utilizes Hibernate as the default JPA provider by default. The dependency tree under the pom shows hibernate-related dependencies.

The actuator is mostly used to expose operational data about a running application, such as health, metrics, info, dump, env, etc. It allows us to connect with it via HTTP endpoints or JMX beans. Once this dependency is added to the classpath, we have access to multiple endpoints right away.

To construct a Docker image using Gradle build configuration, we must first install the docker plugin and then develop a build docker task.

Using @ExceptionHandler on methods of @ControllerAdvice classes to apply exception-handling globally or to a subset of controllers is the most frequent method. ControllerAdvice is an annotation added in Spring 3.2 that provides “Advice” for multiple controllers.

To use Spring Boot to implement Redis Cache, we must first construct a tiny application with CRUD activities. The Redis Cache feature will be used in the Retrieve, Update, and Delete operations.

  • Create or clone a Spring Boot project first. In my example, we used Spring Initializr to create a Spring Boot project, which we then downloaded to my PC by clicking the button or pressing Ctrl + Enter on the keyboard. 
  • Open Eclipse/STS and go to File » Import after unzipping the downloaded file.
  • Go to Maven » Existing Maven Project » Next, after searching for Maven and expanding the folder.
  • Go to the location on your computer where you unzipped the downloaded Spring Boot project. It will look for the file pom.xml. Choose your pom.xml project and click the Finish button.
  • And that’s all.

To prevent CSRF attacks, we must ensure that the request contains something that the evil site cannot give. The Synchronizer Token Pattern is one solution. This option is to need a randomly generated token as an HTTP parameter in addition to our session cookie for each request.

The JUnit testing framework can be used to test Spring Boot microservices by annotating the test with @Test.

Spring is simple to understand since the entire framework is built to deal with POJOs rather than special interfaces, abstract classes, or other methods.

The ‘new normal’ is microservice architectures. Building small, self-contained, ready-to-run applications can provide more flexibility and robustness to your code. Many purpose-built capabilities in Spring Boot make it simple to design and run microservices in production at scale.

Hibernate is aware of the mappings between objects and tables that we create. It guarantees that data from the database is stored and retrieved according to the mappings. On top of JPA, Hibernate provides extra functionalities. However, relying on them would lock you inside Hibernate.

Spring Data REST is a framework that constructs itself on top of an application’s data repositories and exposes them as REST endpoints. Spring Data REST leverages hypermedia-driven endpoints to make it easier for clients to discover the HTTP access points exposed by repositories.

Spring Boot Starters are dependency descriptors that can be added to the pom.xml section of the dependencies section. Spring Boot Starters for various Spring and related technologies are in the hundreds. All of the dependencies are grouped in these beginnings.

Spring’s main distinction or feature is dependency injection, but Spring Boot’s main feature is autoconfiguration. Using the Spring Boot Framework, developers can minimize development time and developer effort and enhance productivity.

It would help if you manually built setups in the Spring framework. There are default configurations in Spring Boot that allow for speedier bootstrapping. To build a web project with Spring Framework, you’ll need a few requirements. On the other hand, Spring Boot can help you get your app up and running with just one dependency.

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