SpringBootApplication 注解

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发布于: 2021 年 06 月 09 日

SpringBootApplication 是一个联合注解,但是到底都联合了哪些注解呢，容器启动过程中加载 bean 会用到，所以有必要看一下.

SpringBootApplication 注解

@Target(ElementType.TYPE)@Retention(RetentionPolicy.RUNTIME)@Documented@Inherited@SpringBootConfiguration@EnableAutoConfiguration@ComponentScan(excludeFilters = @Filter(type = FilterType.CUSTOM, classes = TypeExcludeFilter.class))public @interface SpringBootApplication {
   Class<?>[] exclude() default {};
   String[] excludeName() default {};     @AliasFor(annotation = ComponentScan.class, attribute = "basePackages")   String[] scanBasePackages() default {};     @AliasFor(annotation = ComponentScan.class, attribute = "basePackageClasses")   Class<?>[] scanBasePackageClasses() default {};}

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ComponentScan 注解

@Retention(RetentionPolicy.RUNTIME)@Target(ElementType.TYPE)@Documented@Repeatable(ComponentScans.class)public @interface ComponentScan {   @AliasFor("basePackages")   String[] value() default {};   @AliasFor("value")   String[] basePackages() default {};   Class<?>[] basePackageClasses() default {};   Class<? extends BeanNameGenerator> nameGenerator() default BeanNameGenerator.class;   Class<? extends ScopeMetadataResolver> scopeResolver() default AnnotationScopeMetadataResolver.class;   ScopedProxyMode scopedProxy() default ScopedProxyMode.DEFAULT;   String resourcePattern() default ClassPathScanningCandidateComponentProvider.DEFAULT_RESOURCE_PATTERN;   boolean useDefaultFilters() default true;   Filter[] includeFilters() default {};   Filter[] excludeFilters() default {};   boolean lazyInit() default false;   @Retention(RetentionPolicy.RUNTIME)   @Target({})   @interface Filter {      FilterType type() default FilterType.ANNOTATION;      @AliasFor("classes")      Class<?>[] value() default {};      @AliasFor("value")      Class<?>[] classes() default {};      String[] pattern() default {};   }}

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使用：生成 beanName 的时候不特别指定用的是 AnnotationBeanNameGenerator.class

SpringBootConfiguration 注解

@Target(ElementType.TYPE)@Retention(RetentionPolicy.RUNTIME)@Documented@Configurationpublic @interface SpringBootConfiguration {}

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Configuration 注解

@Target(ElementType.TYPE)@Retention(RetentionPolicy.RUNTIME)@Documented@Componentpublic @interface Configuration {   String value() default "";}

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Component 注解

@Target(ElementType.TYPE)@Retention(RetentionPolicy.RUNTIME)@Documentedpublic @interface Component {   /**    * The value may indicate a suggestion for a logical component name,    * to be turned into a Spring bean in case of an autodetected component.    * @return the suggested component name, if any    */   String value() default "";}

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EnableAutoConfiguration 注解

@Target(ElementType.TYPE)@Retention(RetentionPolicy.RUNTIME)@Documented@Inherited@AutoConfigurationPackage@Import(EnableAutoConfigurationImportSelector.class)public @interface EnableAutoConfiguration {   String ENABLED_OVERRIDE_PROPERTY = "spring.boot.enableautoconfiguration";   Class<?>[] exclude() default {};   String[] excludeName() default {};}

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AutoConfigurationPackage 注解

@Target(ElementType.TYPE)@Retention(RetentionPolicy.RUNTIME)@Documented@Inherited@Import(AutoConfigurationPackages.Registrar.class)public @interface AutoConfigurationPackage {
}

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Import 注解

ConfigurationClassParser 里有关于 import 的处理

public @interface Import {
	/**	 * {@link Configuration}, {@link ImportSelector}, {@link ImportBeanDefinitionRegistrar}	 * or regular component classes to import.	 */	Class<?>[] value();
}

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Bean 注解

@Target({ElementType.METHOD, ElementType.ANNOTATION_TYPE})@Retention(RetentionPolicy.RUNTIME)@Documentedpublic @interface Bean {
	/**	 * Alias for {@link #name}.	 * <p>Intended to be used when no other attributes are needed, for example:	 * {@code @Bean("customBeanName")}.	 * @since 4.3.3	 * @see #name	 */	@AliasFor("name")	String[] value() default {};
	/**	 * The name of this bean, or if several names, a primary bean name plus aliases.	 * <p>If left unspecified, the name of the bean is the name of the annotated method.	 * If specified, the method name is ignored.	 * <p>The bean name and aliases may also be configured via the {@link #value}	 * attribute if no other attributes are declared.	 * @see #value	 */	@AliasFor("value")	String[] name() default {};
	/**	 * Are dependencies to be injected via convention-based autowiring by name or type?	 * <p>Note that this autowire mode is just about externally driven autowiring based	 * on bean property setter methods by convention, analogous to XML bean definitions.	 * <p>The default mode does allow for annotation-driven autowiring. "no" refers to	 * externally driven autowiring only, not affecting any autowiring demands that the	 * bean class itself expresses through annotations.	 * @see Autowire#BY_NAME	 * @see Autowire#BY_TYPE	 */	Autowire autowire() default Autowire.NO;
	String initMethod() default "";		String destroyMethod() default AbstractBeanDefinition.INFER_METHOD;
}