An introduction to Spring Boot programming that even beginners can easily master

Spring Boot is a framework for rapid development of web applications and microservices, which can simplify the development process and improve development efficiency. But for beginners, it is not enough to understand the theoretical knowledge of Spring Boot. They also need to master practical operations and development skills. In this article, we will introduce some introductory guides to Spring Boot programming that beginners can easily master.

1. Basic concepts of Spring Boot

Before learning any programming language or framework, you first need to understand its basic concepts. Spring Boot is based on the Java language. Its core is to rely on the idea of ​​​​convention over configuration, which greatly reduces the developer's coding workload and can be used out of the box. Spring Boot can automatically configure a variety of development components, so developers only need to focus on the development of business logic.

2. Environment setup

Before you start programming with Spring Boot, you need to ensure that the environment is configured correctly. You need to install JDK and Spring Boot's integrated development tool (IDE). It is recommended to use IntelliJ IDEA or Eclipse. In addition, you also need to install Maven or Gradle, which are tools for building and managing Java projects.

3. Create a Spring Boot project

There are many ways to create a Spring Boot project in the IDE; you can directly create a Spring Boot project based on Maven or Gradle, or you can use Spring Boot Initializr's website (https://start.spring.io/) is created. When creating a project, you need to select the Spring Boot version, dependency packages, types and other matters.

4. Write the first Spring Boot application

After creating a Spring Boot project, you can start writing code. First, we need to define a controller class that accepts requests and returns responses.

@RestController
public class HelloController {
    
    @GetMapping("/hello")
    public String hello(){
        return "Hello, World!";
    }
}

Use the @RestController annotation on the controller to indicate that this is a RESTful service. Use the @GetMapping annotation on the method to indicate that this is an HTTP GET request processing function and specify the requested URL path. In the method, we simply return a string.

Next, you need to start the application to test the code. The application can be started using the IDE's "Run" button or the java -jar command. If the startup is successful, you should be able to access the sentence "Hello, World!" in the browser.

5. Use Spring Boot’s automatic configuration

Spring Boot’s automatic configuration function allows developers to focus more on business development, and leaves the underlying framework building process to Spring Boot, making Development becomes more efficient. For example, when using Spring Boot to create a Web application, you only need to add the spring-boot-starter-web dependency to automatically configure the embedded Tomcat server and Spring MVC framework.

There are many other automatic configuration dependencies in Spring Boot, such as:

• spring-boot-starter-data-jpa: Automatic configuration JPA (Java Persistence API)
• spring-boot-starter-data-mongodb: Automatically configure MongoDB
• spring-boot-starter-actuator: Automatically configure application health checks, metrics and monitoring, etc.

6. Using Spring Boot configuration files

It is a good habit to use configuration files in Spring Boot applications. It can separate important configuration information from the code and improve maintainability. . Spring Boot supports multiple types of configuration files, such as .properties and .yml.

The following is a application.propertiessample configuration file:

server.port=8080
spring.datasource.url=jdbc:mysql://localhost:3306/testdb
spring.datasource.username=root
spring.datasource.password=password

In this configuration file, we specify the listening port, database connection URL, and user for the application information such as name and password.

7. Using Spring Boot annotations

Spring Boot borrows many useful annotations from the core framework. Developers can use these annotations to define beans, control transactions, enable caching, etc. The following are some commonly used Spring Boot annotations:

• @Bean: Define a Bean in the container
• @Transactional: Enable transaction processing
• @EnableCaching: Enable caching
• @Component: Define a Java class as a component
• @Autowired: Inject a Bean by type or name

8. Test framework using Spring Boot

Testing is an important means to ensure code quality and reliability. Spring Boot provides a rich testing framework to assist developers in unit testing, integration testing and other tests. The following are some commonly used testing frameworks:

• JUnit: Unit testing framework written based on Java
• Mockito: Java Mock testing framework
• Spring Test: Spring Boot integration Testing framework
• Selenium: Web application UI testing framework

9. Summary

This article introduces the basic concepts of Spring Boot, environment construction, and creation of Spring Boot projects , writing the first Spring Boot application, using Spring Boot's automatic configuration, using Spring Boot's configuration files, using Spring Boot's annotations, using Spring Boot's testing framework, etc. I hope this article can help beginners quickly get started with Spring Boot programming and provide a reference for actual development.

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