@RequestMapping、@GetMapping、@PostMapping_use precise mapping annotation, i.e. '@getmapping'

@RequestMapping

你可以使用@RequestMapping注解来将请求URL，如/appointments等，映射到整个类上或某个特定的处理器方法上。一般来说，类级别的注解负责将一个特定（或符合某种模式）的请求路径映射到一个控制器上，同时通过方法级别的注解来细化映射，即根据特定的HTTP请求方法（“GET”“POST”方法等）、HTTP请求中是否携带特定参数等条件，将请求映射到匹配的方法上。

可以在方法和类上使用 @Target({ElementType.TYPE, ElementType.METHOD})

* value() 和 path()等返回值为字符串数组 都可以同时定义多个字符串值来接收多个URL请求

@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Mapping
public @interface RequestMapping {
    String name() default "";
 
    @AliasFor("path")
    String[] value() default {};
 
    @AliasFor("value")
    String[] path() default {};
 
    RequestMethod[] method() default {};
 
    String[] params() default {};
 
    String[] headers() default {};
 
    String[] consumes() default {};
 
    String[] produces() default {};
}

@PostMapping

@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@RequestMapping(
    method = {RequestMethod.POST}
)
public @interface PostMapping {
    @AliasFor(
        annotation = RequestMapping.class
    )
    String name() default "";
 
    @AliasFor(
        annotation = RequestMapping.class
    )
    String[] value() default {};
 
    @AliasFor(
        annotation = RequestMapping.class
    )
    String[] path() default {};
 
    @AliasFor(
        annotation = RequestMapping.class
    )
    String[] params() default {};
 
    @AliasFor(
        annotation = RequestMapping.class
    )
    String[] headers() default {};
 
    @AliasFor(
        annotation = RequestMapping.class
    )
    String[] consumes() default {};
 
    @AliasFor(
        annotation = RequestMapping.class
    )
    String[] produces() default {};
}

等于是@RequestMapping(value = "/", method = RequestMethod.POST)的缩写

@GetMapping

@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@RequestMapping(
    method = {RequestMethod.GET}
)
public @interface GetMapping {
    @AliasFor(
        annotation = RequestMapping.class
    )
    String name() default "";
 
    @AliasFor(
        annotation = RequestMapping.class
    )
    String[] value() default {};
 
    @AliasFor(
        annotation = RequestMapping.class
    )
    String[] path() default {};
 
    @AliasFor(
        annotation = RequestMapping.class
    )
    String[] params() default {};
 
    @AliasFor(
        annotation = RequestMapping.class
    )
    String[] headers() default {};
 
    @AliasFor(
        annotation = RequestMapping.class
    )
    String[] consumes() default {};
 
    @AliasFor(
        annotation = RequestMapping.class
    )
    String[] produces() default {};
}

等于是@RequestMapping(value = "/", method = RequestMethod.GET)的缩写