The role of @requestmapping in the project and how to use it

One 、 effect
In our Spring In the project , adopt @Controller After the annotation finds the corresponding control class , You also need to know how each specific request is handled inside the controller , And that's where it comes in org.springframework.web.bind.annotation.RequestMapping Note the . RequestMapping Annotation types are used to map a request or a method , Its annotation form is @RequestMapping , You can use this annotation to mark in a request , That is, our specific method .

Two 、 Use

[email protected] Mark on class
When labeled on a class , All methods in the class will be mapped to requests relative to the class level , Indicates that all requests processed by the controller are mapped to value The path specified by the property value .

In the diagram above , Add our @RequestMapping After the note , Our login request url namely （/user/login）、 Registration request url namely （/user/register）

[email protected] Mark on the method
When annotated on a method , This method will become a request processing method , It will receive the corresponding... In the program URL When called .

[email protected] Properties of annotations

Be careful ： All properties are optional , But its default attribute is value . When value Is its unique property , Property names can be omitted , For example, the following two labels have the same meaning :
@RequestMapping(value = “/login”)
@RequestMapping(“/login”)