RequestHeader (Spring Framework 5.2.12.RELEASE API)

```
@Target(PARAMETER)
@Retention(RUNTIME)
@Documented
public @interface RequestHeader
```
Annotation which indicates that a method parameter should be bound to a web request header.
Supported for annotated handler methods in Spring MVC and Spring WebFlux.
If the method parameter is Map<String, String>, MultiValueMap<String, String>, or HttpHeaders then the map is populated with all header names and values.
Since:
3.0
Author:
Juergen Hoeller, Sam Brannen
See Also:
RequestMapping, RequestParam, CookieValue

Optional Element Summary

Optional Elements
Modifier and Type	Optional Element	Description
`String`	`defaultValue`	The default value to use as a fallback.
`String`	`name`	The name of the request header to bind to.
`boolean`	`required`	Whether the header is required.
`String`	`value`	Alias for `name()`.

- Element Detail
  - value
```
@AliasFor("name")
String value
```
    Alias for name().
    Default:
    ""
- - name
```
@AliasFor("value")
String name
```
    The name of the request header to bind to.
    Since:
    4.2
    Default:
    ""
- - required
```
boolean required
```
    Whether the header is required.
    Defaults to true, leading to an exception being thrown if the header is missing in the request. Switch this to false if you prefer a null value if the header is not present in the request.
    Alternatively, provide a defaultValue(), which implicitly sets this flag to false.
    Default:
    true
- - defaultValue
```
String defaultValue
```
    The default value to use as a fallback.
    Supplying a default value implicitly sets required() to false.
    Default:
    "\n\t\t\n\t\t\n\ue000\ue001\ue002\n\t\t\t\t\n"