Create a Custom Auto-Configuration with Spring Boot

迷南。 2024-03-25 19:48 67阅读 0赞

The Spring Boot auto-configuration helps us automatically configure a Spring application based on the dependencies that are present on the classpath

This can make development faster and easier by eliminating the need to define certain beans included in the auto-configuration classes.

In the following section, we’ll look at `creating our custom Spring Boot auto-configuration`.

--------------------

## Maven Dependencies ##

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
        <version>2.4.0</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.19</version>
    </dependency>

--------------------

## Creating a Custom Auto-Configuration ##

> Create a custom auto-configuration 仅需2步  
> 1、create a class annotated as @Configuration  
> 2、把此类注册到约定的路径下

# Step1： Create a custom configuration for a MySQL data source
    @Configuration
    public class MySQLAutoconfiguration {
        
        //...
    }
    
    # Step2： Register the class as an auto-configuration candidate（候选人）.
    # in the standard file resources/META-INF/spring.factories
    org.springframework.boot.autoconfigure.EnableAutoConfiguration = \com.autoconfiguration.MySQLAutoconfiguration

If we want our auto-configuration class to have `priority` over other candidates, we can add the **`@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE)`** annotation.

Note that the `auto-configuration` is only in effect if we don’t define `the auto-configured beans` in the application. If we define our bean, it will override the default one.

**参考: [Create a Custom Auto-Configuration with Spring Boot][]**

[Create a Custom Auto-Configuration with Spring Boot]: https://www.baeldung.com/spring-boot-custom-auto-configuration