MapStruct No qualifying bean

同时使用 Lombok 和 MapStruct，编译运行报错：

No qualifying bean of type 'xxx' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {}

原因：@Mapper 注解不能向容器中注入 bean。

解决： @Mapper 注解填写 componentModel 属性值，如下：

@Mapper(componentModel = MappingConstants.ComponentModel.SPRING)

默认 DEFAULT 不使用任何组件模型，通常通过 org.mapstruct.factory.Mappers.getMapper(Class) 检索实例。

配合 Spring 使用的话应该设置为 SPRING，这样生成的 mapper 实现类是一个 Spring bean 进而可以通过 @Autowired 注入。

还有其他多种取值例如 CDI、JSR330、JAKARTA 等等，可以查看源码

    /**
    * Specifies the component model constants to which the generated mapper should adhere.
    * It can be used with the annotation {@link Mapper#componentModel()} or {@link MapperConfig#componentModel()}
    *
    * <p>
    * <strong>Example:</strong>
    * </p>
    * <pre><code class='java'>
    * // Spring component model
    * &#64;Mapper(componentModel = MappingConstants.ComponentModel.SPRING)
    * </code></pre>
    *
    * @since 1.5.0
    */
    public static final class ComponentModel {

        private ComponentModel() {
        }

        /**
         * The mapper uses no component model, instances are typically retrieved
         * via {@link org.mapstruct.factory.Mappers#getMapper(java.lang.Class)}
         *
         */
        public static final String DEFAULT = "default";

        /**
         * The generated mapper is an application-scoped CDI bean and can be retrieved via @Inject.
         * The annotations are either from {@code javax} or {@code jakarta}.
         * Priority have the {@code javax} annotations.
         * In case you want to only use Jakarta then use {@link #JAKARTA_CDI}.
         *
         * @see #JAKARTA_CDI
         */
        public static final String CDI = "cdi";

        /**
         * The generated mapper is a Spring bean and can be retrieved via @Autowired
         *
         */
        public static final String SPRING = "spring";

        /**
         * The generated mapper is annotated with @Named and @Singleton, and can be retrieved via @Inject.
         * The annotations are either from {@code javax.inject} or {@code jakarta.inject}.
         * Priority have the {@code javax.inject} annotations.
         * In case you want to only use Jakarta then use {@link #JAKARTA}.
         *
         * @see #JAKARTA
         */
        public static final String JSR330 = "jsr330";

        /**
         * The generated mapper is annotated with @Named and @Singleton, and can be retrieved via @Inject.
         * The annotations are from {@code jakarta.inject}.
         * In case you want to use {@code javax.inject} then use {@link #JSR330}.
         *
         * @see #JSR330
         */
        public static final String JAKARTA = "jakarta";

        /**
         * The generated mapper is an application-scoped Jakarta CDI bean and can be retrieved via @Inject.
         * @see #CDI
         */
        public static final String JAKARTA_CDI = "jakarta-cdi";

    }