Annotation Name	Region	Description	Comment
@Bean	METHOD, ANNOTATION_TYPE	Indicates that a method produces a bean to be managed by the Spring container.
@Component	ANNOTATION_TYPE	Indicates that an annotated class is a “component”. Such classes are considered as candidates for auto-detection when using annotation-based configuration and classpath scanning.
@Configuration	TYPE	Indicates current class is a configuration class. Auto-scanned by Spring container.
@Scope	TYPE, METHOD	When used as a type-level annotation in conjunction with indicates the name of a scope to use for instances of the annotated type.
@ResponseBody	Method	Normally, a response from a controller will be considered as a redirect path, be adding @ResponseBody, the returned results are considered as “Object”, most likely, JSON	We use this annotation for AJAX.
@Mapper	TYPE	@Mapper normally works on a interface for MyBatis, the methods declared in the interface will load their mybatis CRUD annotations to load the SQL.	Work for MyBatis on interface.
@Transactional	METHOD, TYPE	@Transactional works on Class or method, it will ensure the safety of transaction of SQL database.	Transactional works on multiple sql commands and will roll back when error happens in current transaction.
@Valid	METHOD, FIELD, CONSTRUCTOR, PARAMETER, TYPE_USE	Majorly, @Valid is used on spring auto binding parameters. It will follow the class given in @Constraint, if return false in the isValid method, it will throw a BindException.	We can create our own validation annotations by following the rules and use globalExceptionHandler to deal with the exceptions.
@CookieValue	PARAMETER	Cookie value is used to bind value in Cookie, we can specify the cookie name and bind the value to parameters.
@RequestParam	PARAMETER	RequestParam is used for parsing key=value&key1=value1 parameter. This method is vary similar as @PathParam, though @PathParam used for parsing the values saved in path.