@Configuration+@Bean & @Component & @Resource/@autowired/@Inject

@Configuration+@Bean

示例代码：

@Configuration
@ComponentScan(basePackages = WebConfig.PACKAGE_NAMESPACE)
@EnableWebMvc
public class WebConfig extends WebMvcConfigurerAdapter implements ApplicationContextAware {

private ApplicationContext applicationContext;

<span style="white-space:pre">	</span>....................

@Bean
public CommonsMultipartResolver multipartResolver() {
final CommonsMultipartResolver commonsMultipartResolver = new CommonsMultipartResolver();
commonsMultipartResolver.setMaxUploadSize(MAX_UPLOAD_SIZE);
return commonsMultipartResolver;
}

@Bean
public TemplateEngine templateEngine() {
final SpringTemplateEngine engine = new SpringTemplateEngine();
engine.setEnableSpringELCompiler(true);
engine.setTemplateResolver(this.templateResolver());
return engine;
}

@Bean(name = "messageSource")
public ReloadableResourceBundleMessageSource getMessageSource() {
final ReloadableResourceBundleMessageSource resource = new ReloadableResourceBundleMessageSource();
resource.setBasenames("classpath:i18n/application-messages");
resource.setDefaultEncoding("UTF-8");
return resource;
}

<span style="white-space:pre">		</span>................................

}

@Configuration相当于<beans>标签，所以此处WebConfig.class相当于一个xml配置文件而不是一个bean
@Bean相当于<bean>标签，但我的理解是，它所描述的bean只能是没有引入其他类的简单的bean

@Component

示例代码：

@Service
@Transactional
public class XXServiceImpl implements XXService{

@Autowired
TerminalRepository terminalRepository;

@Autowired
ProductRepository productRepository;

...........

@Component(@Controller  @Service  @Repository) 也相当于<bean>标签，但我的理解是，他们所描述的不是像@Bean那样简单的bean

@Resource/@autowired/@Inject

前面的都是注入的注解，相当于“存”，而这三个就相当于“取”