스프링 MVC - 구조 이해

protected void doDispatch(HttpServletRequest request, HttpServletResponse response) throws Exception {
    
    HttpServletRequest processedRequest = request;
    HandlerExecutionChain mappedHandler = null;
    ModelAndView mv = null;
    
    // 1. 핸들러 조회
    mappedHandler = getHandler(processedRequest);
    if (mappedHandler == null) {
		noHandlerFound(processedRequest, response);
        return;
    }
    
    // 2. 핸들러 어댑터 조회 - 핸들러를 처리할 수 있는 어댑터
    HandlerAdapter ha = getHandlerAdapter(mappedHandler.getHandler());
    
    // 3. 핸들러 어댑터 실행 -> 4. 핸들러 어댑터를 통해 핸들러 실행 -> 5. ModelAndView 반환
    mv = ha.handle(processedRequest, response, mappedHandler.getHandler());
    
    processDispatchResult(processedRequest, response, mappedHandler, mv, dispatchException);
    
}

private void processDispatchResult(HttpServletRequest request, HttpServletResponse response, 
                                   HandlerExecutionChain mappedHandler, ModelAndView mv, Exception exception) throws Exception {
    
    // 뷰 렌더링 호출
    render(mv, request, response);
}

protected void render(ModelAndView mv, HttpServletRequest request, HttpServletResponse response) throws Exception {
    
    View view;
    String viewName = mv.getViewName();
    
    // 6. 뷰 리졸버를 통해서 뷰 찾기, 7. View 반환
    view = resolveViewName(viewName, mv.getModelInternal(), locale, request);
    
    // 8. 뷰 렌더링
    view.render(mv.getModelInternal(), request, response);
}

public interface Controller {
    
	ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception;
}

package hello.servlet.web.springmvc.old;

import org.springframework.stereotype.Component;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@Component("/springmvc/old-controller")
public class OldController implements Controller {
    
    @Override
    public ModelAndView handleRequest(HttpServletRequest request,
    HttpServletResponse response) throws Exception {
        System.out.println("OldController.handleRequest");
        return null;
    }
}

public interface HttpRequestHandler {
	void handleRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException;
}

package hello.servlet.web.springmvc.old;

import org.springframework.stereotype.Component;
import org.springframework.web.HttpRequestHandler;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Component("/springmvc/request-handler")
public class MyHttpRequestHandler implements HttpRequestHandler {
    
    @Override
    public void handleRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
	    System.out.println("MyHttpRequestHandler.handleRequest");
    }
}

package hello.servlet.web.springmvc.old;

import org.springframework.stereotype.Component;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@Component("/springmvc/old-controller")
public class OldController implements Controller {
    @Override
    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception {
        System.out.println("OldController.handleRequest");
        return new ModelAndView("new-form"); // View 반환
    }
}

package hello.servlet.web.springmvc.v1;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

@Controller
public class SpringMemberFormControllerV1 {
    
    @RequestMapping("/springmvc/v1/members/new-form")
    public ModelAndView process() {
	    return new ModelAndView("new-form");
    }
}

@Component //컴포넌트 스캔을 통해 스프링 빈으로 등록
@RequestMapping
public class SpringMemberFormControllerV1 {
    
	@RequestMapping("/springmvc/v1/members/new-form")
    public ModelAndView process() {
	    return new ModelAndView("new-form");
    }
}

@RequestMapping
public class SpringMemberFormControllerV1 {
    
    @RequestMapping("/springmvc/v1/members/new-form")
    public ModelAndView process() {
    	return new ModelAndView("new-form");
    }
}

//스프링 빈 직접 등록
@Bean
TestController testController() {
	return new TestController();
}

package hello.servlet.web.springmvc.v1;

import hello.servlet.domain.member.Member;
import hello.servlet.domain.member.MemberRepository;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@Controller
public class SpringMemberSaveControllerV1 {
    
    private MemberRepository memberRepository = MemberRepository.getInstance();
    
    @RequestMapping("/springmvc/v1/members/save")
    public ModelAndView process(HttpServletRequest request, HttpServletResponse     response) {
        
        String username = request.getParameter("username");
        int age = Integer.parseInt(request.getParameter("age"));
        
        Member member = new Member(username, age);
        System.out.println("member = " + member);
        memberRepository.save(member);
        
        ModelAndView mv = new ModelAndView("save-result");
        mv.addObject("member", member); // ModelAndView에서 Model 데이터 추가할 때 이용
        return mv;
    }
}

package hello.servlet.web.springmvc.v1;

import hello.servlet.domain.member.Member;
import hello.servlet.domain.member.MemberRepository;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
import java.util.List;

@Controller
public class SpringMemberListControllerV1 {
    
    private MemberRepository memberRepository = MemberRepository.getInstance();
    
    @RequestMapping("/springmvc/v1/members")
    public ModelAndView process() {
        
        List<Member> members = memberRepository.findAll();
        
        ModelAndView mv = new ModelAndView("members");
        mv.addObject("members", members);
        return mv;
    }
}

package hello.servlet.web.springmvc.v2;

import hello.servlet.domain.member.Member;
import hello.servlet.domain.member.MemberRepository;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.List;

/**
* 클래스 단위 -> 메서드 단위
* @RequestMapping 클래스 레벨과 메서드 레벨 조합
*/
@Controller
@RequestMapping("/springmvc/v2/members")
public class SpringMemberControllerV2 {
    
    private MemberRepository memberRepository = MemberRepository.getInstance();
    
    @RequestMapping("/new-form")
    public ModelAndView newForm() {
    	return new ModelAndView("new-form");
    }
    
    @RequestMapping("/save")
    public ModelAndView save(HttpServletRequest request, HttpServletResponse response) {
        
        String username = request.getParameter("username");
        int age = Integer.parseInt(request.getParameter("age"));
        
        Member member = new Member(username, age);
        memberRepository.save(member);
        
        ModelAndView mav = new ModelAndView("save-result");
        mav.addObject("member", member);
        return mav;
    }
    
    @RequestMapping
    public ModelAndView members() {
        
	    List<Member> members = memberRepository.findAll();
        
        ModelAndView mav = new ModelAndView("members");
        mav.addObject("members", members);
        return mav;
    }
}

package hello.servlet.web.springmvc.v3;

import hello.servlet.domain.member.Member;
import hello.servlet.domain.member.MemberRepository;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import java.util.List;

/**
* v3
* Model 도입
* ViewName 직접 반환
* @RequestParam 사용
* @RequestMapping -> @GetMapping, @PostMapping
*/
@Controller
@RequestMapping("/springmvc/v3/members")
public class SpringMemberControllerV3 {
    
    private MemberRepository memberRepository = MemberRepository.getInstance();
    
    @GetMapping("/new-form")
    public String newForm() {
	    return "new-form";
    }
    
    @PostMapping("/save")
    public String save(
            @RequestParam("username") String username,
            @RequestParam("age") int age,
            Model model) {
        
        Member member = new Member(username, age);
        memberRepository.save(member);
        
        model.addAttribute("member", member);
        return "save-result";
    }
    
    @GetMapping
    public String members(Model model) {
        List<Member> members = memberRepository.findAll();
        model.addAttribute("members", members);
        return "members";
    }
}

@RequestMapping(value = "/new-form", method = RequestMethod.GET)

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@RequestMapping(method = RequestMethod.GET)
public @interface GetMapping {
    ...
}