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

@EnableAutoConfiguration

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
@AutoConfigurationPackage  //自動匯入包
@Import(AutoConfigurationImportSelector.class)  //自動匯入類中的  自動匯入類選擇器
public @interface EnableAutoConfiguration {

	/**
	 * Environment property that can be used to override when auto-configuration is
	 * enabled.
	 */
	String ENABLED_OVERRIDE_PROPERTY = "spring.boot.enableautoconfiguration";

	/**
	 * Exclude specific auto-configuration classes such that they will never be applied.
	 * @return the classes to exclude
	 */
	Class<?>[] exclude() default {};

	/**
	 * Exclude specific auto-configuration class names such that they will never be
	 * applied.
	 * @return the class names to exclude
	 * @since 1.3.0
	 */
	String[] excludeName() default {};

}
 

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
@Import(AutoConfigurationPackages.Registrar.class) //自動匯入包中的註冊類
public @interface AutoConfigurationPackage {

	/**
	 * Base packages that should be registered with {@link AutoConfigurationPackages}.
	 * <p>
	 * Use {@link #basePackageClasses} for a type-safe alternative to String-based package
	 * names.
	 * @return the back package names
	 * @since 2.3.0
	 */
	String[] basePackages() default {};

	/**
	 * Type-safe alternative to {@link #basePackages} for specifying the packages to be
	 * registered with {@link AutoConfigurationPackages}.
	 * <p>
	 * Consider creating a special no-op marker class or interface in each package that
	 * serves no purpose other than being referenced by this attribute.
	 * @return the base package classes
	 * @since 2.3.0
	 */
	Class<?>[] basePackageClasses() default {};

}