此版本仍在开发中，尚未被视为稳定版本。对于最新的稳定版本，请使用 Spring Framework 6.2.4！spring-doc.cadn.net.cn

@RequestParam

请参阅 Servlet 堆栈中的等效项spring-doc.cadn.net.cn

您可以使用@RequestParam注解将查询参数绑定到 控制器。以下代码片段显示了用法：spring-doc.cadn.net.cn

@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 用@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.spring-doc.cadn.net.cn

Type conversion is applied automatically if the target method parameter type is not String. See Type Conversion.spring-doc.cadn.net.cn

When a @RequestParam annotation is declared on a Map<String, String> or MultiValueMap<String, String> argument, the map is populated with all query parameters.spring-doc.cadn.net.cn

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.spring-doc.cadn.net.cn