This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Framework 6.1.12! |
@RequestParam
You can use the @RequestParam
annotation to bind query parameters to a method argument in a
controller. The following code snippet shows the usage:
-
Java
-
Kotlin
@Controller
@RequestMapping("/pets")
public class EditPetForm {
// ...
@GetMapping
public String setupForm(@RequestParam("petId") int petId, Model model) { (1)
Pet pet = this.clinic.loadPet(petId);
model.addAttribute("pet", pet);
return "petForm";
}
// ...
}
1 | Using @RequestParam . |
import org.springframework.ui.set
@Controller
@RequestMapping("/pets")
class EditPetForm {
// ...
@GetMapping
fun setupForm(@RequestParam("petId") petId: Int, model: Model): String { (1)
val pet = clinic.loadPet(petId)
model["pet"] = pet
return "petForm"
}
// ...
}
1 | Using @RequestParam . |
The Servlet API “request parameter” concept conflates query parameters, form
data, and multiparts into one. However, in WebFlux, each is accessed individually through
ServerWebExchange . While @RequestParam binds to query parameters only, you can use
data binding to apply query parameters, form data, and multiparts to a
command object.
|
Method parameters that use the @RequestParam
annotation are required by default, but
you can specify that a method parameter is optional by setting the required flag of a @RequestParam
to false
or by declaring the argument with a java.util.Optional
wrapper.
Type conversion is applied automatically if the target method parameter type is not
String
. See Type Conversion.
When a @RequestParam
annotation is declared on a Map<String, String>
or
MultiValueMap<String, String>
argument, the map is populated with all query parameters.
Note that use of @RequestParam
is optional — for example, to set its attributes. By
default, any argument that is a simple value type (as determined by
BeanUtils#isSimpleProperty)
and is not resolved by any other argument resolver is treated as if it were annotated
with @RequestParam
.