스프링 HTTP 요청 파라미터 - @RequestParam

import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Map;

@Slf4j
@Controller
public class RequestParamController {

    @RequestMapping("/request-param-v1")
    public void requestParamV1(HttpServletRequest request, HttpServletResponse response) throws IOException {
        String username = request.getParameter("username");
        int age = Integer.parseInt(request.getParameter("age"));
        log.info("username={}, age={}", username, age);
        response.getWriter().write("ok");

    }

	
    @ResponseBody
    @RequestMapping("/request-param-v2")
    public String requestParamV2(
            @RequestParam("username") String memberName,
            @RequestParam("age") int memberAge){

        log.info("username = {}, age = {}", memberName, memberAge);
        return "ok";
    }

    @ResponseBody
    @RequestMapping("/request-param-v3")
    public String requestParamV3(
            @RequestParam String username,
            @RequestParam int age){

        log.info("username = {}, age = {}", username, age);
        return "ok";
    }

    @ResponseBody
    @RequestMapping("/request-param-v4")
    // http 파라미터 변수 이름과 같으면 @RequestParam 생략가능
    // String, int, Integer 등의 단순 타입이면 @RequestParam도 생략 가능
    public String requestParamV4(String username, int age){

        log.info("username = {}, age = {}", username, age);
        return "ok";
    }

    @ResponseBody
    @RequestMapping("/request-param-required")
    public String requestParamRequired(
            @RequestParam(required = true) String username,
            // 자바에 int에는 null 이 못들어감(기본 형 null X)
            // 요청 파라미터 없는 경우 null 입력 됨
            @RequestParam(required = false) Integer age){

        log.info("username = {}, age = {}", username, age);
        return "ok";
    }

    @ResponseBody
    @RequestMapping("/request-param-default")
    public String requestParamDefault(
            @RequestParam(required = true,defaultValue = "guest") String username,
            @RequestParam(required = false, defaultValue = "-1") int age){

        log.info("username = {}, age = {}", username, age);
        return "ok";
    }

    @ResponseBody
    @RequestMapping("/request-param-map")
    // Map을 MultiValueMap으로 조회할 수 있다.
    public String requestParamMap(@RequestParam Map<String,Object> paramMap){

        log.info("username = {}, age = {}", paramMap.get("username"), paramMap.get("age"));
        return "ok";
    }
}