SpringBoot 3.x版本中，自动配置文件的路径 为 
META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports 

之前的版本为 META-INF/spring.factories 

如果一个自定义的自动配置类需要被引入，它的全限定名可以写入到这个文件中

hutool-all-5.8.28.jar  两个配置文件都存在

META-INF/spring.factories
# Auto Configure
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
cn.hutool.extra.spring.SpringUtil


META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports 
cn.hutool.extra.spring.SpringUtil




src/main/resources/META-INF/spring.factories
org.springframework.boot.autoconfigure.EnableAutoConfiguration=a.AutoBean

a.AutoBean 不存在则报错
java.lang.IllegalStateException: Unable to read meta-data for class a.AutoBean

Caused by: java.io.FileNotFoundException: class path resource [a/AutoBean.class] cannot be opened because it does not exist





package a;
// 不需要任何注解
public class AutoBean {

    private static final String ID = "AutoBean_"+System.currentTimeMillis();

    public AutoBean(){
        System.out.println("AutoBean init done");
    }

    public String getId(){
        return ID;
    }
}


import a.AutoBean;
import cn.hutool.extra.spring.SpringUtil;

    @RequestMapping("/hutool_get_auto_bean_id")
    public String get_auto_bean_id() {
        AutoBean autoBean = SpringUtil.getBean(AutoBean.class);
        return autoBean.getId();
    }