SpringBoot: A powerful tool for quickly building efficient web applications!

Design ideas and assembly principles of SpringBoot

SpringBoot is a rapid application development framework for the Spring framework. Its design ideas and assembly principles are worthy of our in-depth study and understanding.

design thinking

The design idea of ​​the SpringBoot framework can be summarized as follows:

1. Convention is better than configuration: SpringBoot provides default conventions and automatic configuration, which avoids a lot of configuration work for developers and improves development efficiency.
2. Componentization: Each module in SpringBoot is managed through components, and each component can be configured, tested and deployed independently.
3. Microservice: SpringBoot supports microservice architecture, which can split a large application into multiple small services, thereby improving the maintainability and scalability of the system.
4. Ease of development and deployment: SpringBoot integrates a variety of development tools and deployment tools, making the development and deployment process easier and more efficient.

Assembly principle

The assembly principle of SpringBoot can be divided into three stages:

1. Automatic scanning: SpringBoot finds all components through the automatic scanning mechanism and registers them in the Spring container.
2. Automatic configuration: SpringBoot automatically configures various components, including data sources, web servers, message queues, etc., according to the needs of the application through the automatic configuration mechanism.
3. Automatic assembly: SpringBoot automatically injects various components into other components through the automatic assembly mechanism, thereby realizing seamless integration between various components.
   Let's take the Web application as an example to understand the assembly principle of SpringBoot in detail.

auto scan

In SpringBoot, all components are defined by annotations. By adding annotations to the startup class of the application @SpringBootApplication, the automatic scanning mechanism can be turned on to find all components.

@SpringBootApplication
public class MyApp {
    
    
    public static void main(String[] args) {
    
    
        SpringApplication.run(MyApp.class, args);
    }
}

automatic configuration

In SpringBoot, automatic configuration is implemented through conditional annotations and automatic configuration classes.
Conditional annotations are @ConditionalOnXxximplemented in a way that Xxxindicates a certain condition, such as @ConditionalOnClassautomatic configuration when a certain class exists. The auto-configuration class is implemented
using @Configurationand , which represent some kind of auto-configuration, such as auto-configuration of all available components.@EnableXxxXxx@EnableAutoConfiguration

@Configuration
@EnableAutoConfiguration
public class MyConfig {
    
    
    // 自动配置数据源
    @Bean
    @ConditionalOnClass(HikariDataSource.class)
    public DataSource dataSource() {
    
    
        return new HikariDataSource();
    }
}

automatic assembly

In SpringBoot, autowiring is @Autowiredachieved through annotations. When a component needs to depend on other components, it only needs to add annotations to the component @Autowired. SpringBoot will automatically scan and inject suitable components into the component.

@Service
public class MyService {
    
    
    @Autowired
    private MyDao dao;
}

interview questions

1. What is the design idea of ​​SpringBoot?
   • Convention over configuration, componentization, microservices, easy development and deployment.
2. How is SpringBoot's automatic configuration implemented?
   • Implemented through conditional annotations and auto-configuration classes.
3. How is SpringBoot's automatic assembly implemented?
   • @Autowiredachieved through annotations.
4. Which annotation must be added to the startup class of SpringBoot?
   • @SpringBootApplicationannotation.
5. How to customize SpringBoot's automatic configuration?
   • Create an @Configurationannotated class and write custom auto-configuration methods.
6. What common data sources does SpringBoot support?
   • Common data sources supported by SpringBoot include HikariCP, Tomcat JDBC Pool, DBCP, C3P0, etc.
7. How to use JPA in SpringBoot?
   • Add annotations to the startup class @EnableJpaRepositories, and configure data sources and JPA-related configurations in the configuration file.
8. How to use Redis in SpringBoot?
   • Configure Redis connection information in the configuration file, use @EnableCachingannotations to enable caching, and use @Cacheableannotations to mark methods that require caching.
9. How to implement transaction management in SpringBoot?
   • Add annotations to the startup class @EnableTransactionManagementand add @Transactionalannotations to the methods that require transaction management.
10. How to configure multiple data sources in SpringBoot?
    • @PrimaryYou can create multiple data sources, and use and annotations in the startup class to distinguish them, and then use annotations to inject the corresponding data sources @Qualifierin the components that need to be used .@Autowired

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The above is all about the design idea and assembly principle of SpringBoot, I hope it will be helpful to everyone.