Você pode ver muito do XXXAware no processo de verificação do código-fonte. Não entrei nisso antes até que vi alguém entrevistando Ali e essa pergunta foi feita. Só decidi descobrir.
(1) O que é Aware?
É uma interface com um espaço em branco e sem métodos.É uma definição vazia, uma marca.
(2) Qual é a utilidade?
Aware significa "perceptível" em inglês. É uma interface em branco, mas tem muitas classes de implementação, então sua função é permitir que o chamador obtenha certas informações, como o nome do contêiner que carrega o Bean atual, O BeanName do Bean atual no contêiner, obtém algumas informações de texto e arquivos de recursos, etc., para obter as informações do carregador que carrega o Bean atual e assim por diante.
Também podemos personalizar alguns XXAware para obter as informações que desejamos.
(3) Como usar?
De acordo com o exposto, desde que a interface Aware seja implementada, é para obter e perceber certas informações. Em seguida, assumimos que precisamos obter o nome e o carregador de classe do Bean atual. Veja como jogar.
Defina um serviço:
@Service
public class TestA implements BeanNameAware , BeanFactoryAware , BeanClassLoaderAware {
private String name;
private String factory;
private String classLoads;
@Override
public void setBeanName(String beanName){
name = beanName;
}
@Override
public void setBeanClassLoader(ClassLoader classLoader) {
classLoads = classLoader.toString();
}
@Override
public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
factory = beanFactory.toString();
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getFactory() {
return factory;
}
public void setFactory(String factory) {
this.factory = factory;
}
public String getClassLoad() {
return classLoads;
}
public void setClassLoad(String classLoad) {
this.classLoads = classLoad;
}
@Override
public String toString() {
return "TestA{" +
"name='" + name + '\'' +
", factory='" + factory + '\'' +
", classLoad='" + classLoads + '\'' +
'}';
}
}
Observe que três interfaces, BeanNameAware, BeanFactoryAware e BeanClassLoaderAware, estão implementadas. Os pais dos três são Aware. De acordo com o que quero dizer, deveria ser para obter o Bean Name, Factory e ClassLoader.
Basta escrever um controlador, iniciar a execução e chamar o método toString deste servidor para ver se ele pode ser lido:
TestA{
name='testA', factory='org.springframework.beans.factory.support.DefaultListableBeanFactory@6fd83fc1: defining beans [org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.event.internalEventListenerProcessor,org.springframework.context.event.internalEventListenerFactory,chatRoomApplication,org.springframework.boot.autoconfigure.internalCachingMetadataReaderFactory,chatRoom,jdbcTestController,testA,webSocketConfig,webSocketServer,serverEndpointExporter,org.springframework.boot.autoconfigure.AutoConfigurationPackages,org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration,propertySourcesPlaceholderConfigurer,org.springframework.boot.autoconfigure.websocket.servlet.WebSocketServletAutoConfiguration$TomcatWebSocketConfiguration,websocketServletWebServerCustomizer,org.springframework.boot.autoconfigure.websocket.servlet.WebSocketServletAutoConfiguration,org.springframework.boot.autoconfigure.web.servlet.ServletWebServerFactoryConfiguration$EmbeddedTomcat,tomcatServletWebServerFactory,org.springframework.boot.autoconfigure.web.servlet.ServletWebServerFactoryAutoConfiguration,servletWebServerFactoryCustomizer,tomcatServletWebServerFactoryCustomizer,org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor,org.springframework.boot.context.internalConfigurationPropertiesBinderFactory,org.springframework.boot.context.internalConfigurationPropertiesBinder,org.springframework.boot.context.properties.BoundConfigurationProperties,org.springframework.boot.context.properties.ConfigurationBeanFactoryMetadata,server-org.springframework.boot.autoconfigure.web.ServerProperties,webServerFactoryCustomizerBeanPostProcessor,errorPageRegistrarBeanPostProcessor,org.springframework.boot.autoconfigure.web.servlet.DispatcherServletAutoConfiguration$DispatcherServletConfiguration,dispatcherServlet,spring.mvc-org.springframework.boot.autoconfigure.web.servlet.WebMvcProperties,org.springframework.boot.autoconfigure.web.servlet.DispatcherServletAutoConfiguration$DispatcherServletRegistrationConfiguration,dispatcherServletRegistration,org.springframework.boot.autoconfigure.web.servlet.DispatcherServletAutoConfiguration,org.springframework.boot.autoconfigure.task.TaskExecutionAutoConfiguration,taskExecutorBuilder,applicationTaskExecutor,spring.task.execution-org.springframework.boot.autoconfigure.task.TaskExecutionProperties,org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration$WhitelabelErrorViewConfiguration,error,beanNameViewResolver,org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration$DefaultErrorViewResolverConfiguration,conventionErrorViewResolver,org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration,errorAttributes,basicErrorController,errorPageCustomizer,preserveErrorControllerTargetClassPostProcessor,spring.resources-org.springframework.boot.autoconfigure.web.ResourceProperties,org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration$EnableWebMvcConfiguration,requestMappingHandlerAdapter,requestMappingHandlerMapping,welcomePageHandlerMapping,mvcConversionService,mvcValidator,mvcContentNegotiationManager,mvcPathMatcher,mvcUrlPathHelper,viewControllerHandlerMapping,beanNameHandlerMapping,routerFunctionMapping,resourceHandlerMapping,mvcResourceUrlProvider,defaultServletHandlerMapping,handlerFunctionAdapter,mvcUriComponentsContributor,httpRequestHandlerAdapter,simpleControllerHandlerAdapter,handlerExceptionResolver,mvcViewResolver,mvcHandlerMappingIntrospector,org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter,defaultViewResolver,viewResolver,requestContextFilter,org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration,formContentFilter,org.springframework.boot.autoconfigure.aop.AopAutoConfiguration$ClassProxyingConfiguration,org.springframework.boot.autoconfigure.aop.AopAutoConfiguration,org.springframework.boot.autoconfigure.availability.ApplicationAvailabilityAutoConfiguration,applicationAvailability,org.springframework.boot.autoconfigure.context.ConfigurationPropertiesAutoConfiguration,org.springframework.boot.autoconfigure.context.LifecycleAutoConfiguration,lifecycleProcessor,spring.lifecycle-org.springframework.boot.autoconfigure.context.LifecycleProperties,org.springframework.boot.autoconfigure.dao.PersistenceExceptionTranslationAutoConfiguration,persistenceExceptionTranslationPostProcessor,org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration$Jackson2ObjectMapperBuilderCustomizerConfiguration,standardJacksonObjectMapperBuilderCustomizer,spring.jackson-org.springframework.boot.autoconfigure.jackson.JacksonProperties,org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration$JacksonObjectMapperBuilderConfiguration,jacksonObjectMapperBuilder,org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration$ParameterNamesModuleConfiguration,parameterNamesModule,org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration$JacksonObjectMapperConfiguration,jacksonObjectMapper,org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration,jsonComponentModule,org.springframework.boot.autoconfigure.http.HttpMessageConvertersAutoConfiguration$StringHttpMessageConverterConfiguration,stringHttpMessageConverter,org.springframework.boot.autoconfigure.http.JacksonHttpMessageConvertersConfiguration$MappingJackson2HttpMessageConverterConfiguration,mappingJackson2HttpMessageConverter,org.springframework.boot.autoconfigure.http.JacksonHttpMessageConvertersConfiguration,org.springframework.boot.autoconfigure.http.HttpMessageConvertersAutoConfiguration,messageConverters,org.springframework.boot.autoconfigure.info.ProjectInfoAutoConfiguration,spring.info-org.springframework.boot.autoconfigure.info.ProjectInfoProperties,org.springframework.boot.autoconfigure.task.TaskSchedulingAutoConfiguration,taskSchedulerBuilder,spring.task.scheduling-org.springframework.boot.autoconfigure.task.TaskSchedulingProperties,org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration,spring.datasource-org.springframework.boot.autoconfigure.jdbc.DataSourceProperties,org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration,platformTransactionManagerCustomizers,spring.transaction-org.springframework.boot.autoconfigure.transaction.TransactionProperties,org.springframework.boot.autoconfigure.web.client.RestTemplateAutoConfiguration,restTemplateBuilder,org.springframework.boot.autoconfigure.web.embedded.EmbeddedWebServerFactoryCustomizerAutoConfiguration$TomcatWebServerFactoryCustomizerConfiguration,tomcatWebServerFactoryCustomizer,org.springframework.boot.autoconfigure.web.embedded.EmbeddedWebServerFactoryCustomizerAutoConfiguration,org.springframework.boot.autoconfigure.web.servlet.HttpEncodingAutoConfiguration,characterEncodingFilter,localeCharsetMappingsCustomizer,org.springframework.boot.autoconfigure.web.servlet.MultipartAutoConfiguration,multipartConfigElement,multipartResolver,spring.servlet.multipart-org.springframework.boot.autoconfigure.web.servlet.MultipartProperties,org.springframework.boot.autoconfigure.websocket.servlet.WebSocketMessagingAutoConfiguration]; root of factory hierarchy', classLoad='sun.misc.Launcher$AppClassLoader@18b4aac2'}
Você pode ver que foi um sucesso. Então é isso que a Aware informa. Quando você precisa obter algumas informações sobre o Bean atual, não é necessário hard-code ou injetá-lo para obtê-lo e obtê-lo diretamente por meio de uma interface definida. Acoplado.
