[Spring] Server to Server 통신 - Custom Header, Json활용

아래와 같은 Json파일을 만들고자한다.

이러한 형태를 사용하는 이유는 json형식을 만드는 코드를 매번 작성할 필요없이 body 내용만을 변경하여 사용할 수있다.

{
	"header":{
		"responseCode": null
	},
	"resBody":{
		"name": "steve",
		"age": 10
	}
}

 

클라이언트

Req.java

public class Req<T> {
    private Header header;
    private T resBody;

    public static class Header {
        private String responseCode;

        public String getResponseCode() {
            return responseCode;
        }

        public void setResponseCode(String responseCode) {
            this.responseCode = responseCode;
        }

        @Override
        public String toString() {
            return "Header{" +
                    "responseCode='" + responseCode + '\'' +
                    '}';
        }
    }

    public Header getHeader() {
        return header;
    }

    public void setHeader(Header header) {
        this.header = header;
    }

    public T getResBody() {
        return resBody;
    }

    public void setResBody(T resBody) {
        this.resBody = resBody;
    }

    @Override
    public String toString() {
        return "Req{" +
                "header=" + header +
                ", body=" + resBody +
                '}';
    }
}

ApiController.java

import com.example.client.dto.Req;
import com.example.client.dto.UserResponse;
import com.example.client.service.RestTemplateService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/api/client")
public class ApiController {
    @Autowired
    private RestTemplateService restTemplateService;

    public ApiController(RestTemplateService restTemplateService) {
        this.restTemplateService = restTemplateService;
    }

    @GetMapping("hello3")
    public Req<UserResponse> gethello3() {
        return restTemplateService.genericExchange();
    }
}

RestTemplateService.java

import com.example.client.dto.Req;
import com.example.client.dto.UserRequest;
import com.example.client.dto.UserResponse;
import org.springframework.core.ParameterizedTypeReference;
import org.springframework.http.MediaType;
import org.springframework.http.RequestEntity;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.util.UriComponentsBuilder;

import java.net.URI;

@Service
public class RestTemplateService {
    // 커스텀헤더
    public UserResponse exchange() {
        URI uri = UriComponentsBuilder
                .fromUriString("http://localhost:9090")
                .path("/api/server/user/{userId}/name/{userName}")
                .encode()
                .build()
                .expand(100, "steve")
                .toUri();
        System.out.println(uri);

        UserRequest req = new UserRequest();
        req.setName("steve");
        req.setAge(10);

        RequestEntity<UserRequest> requestEntity = RequestEntity
                .post(uri)
                .contentType(MediaType.APPLICATION_JSON)
                .header("x-authorization", "abcd")
                .header("custom-header", "fffff")
                .body(req);

        RestTemplate restTemplate = new RestTemplate();
        ResponseEntity<UserResponse> response = restTemplate.exchange(requestEntity, UserResponse.class);
        return response.getBody();
    }

	//Json형식 재사용
    public Req<UserResponse> genericExchange() {
        URI uri = UriComponentsBuilder
                .fromUriString("http://localhost:9090")
                .path("/api/server/user/{userId}/name/{userName}")
                .encode()
                .build()
                .expand(100, "steve")
                .toUri();
        System.out.println(uri);

        UserRequest userRequest = new UserRequest();
        userRequest.setName("steve");
        userRequest.setAge(10);

        Req<UserRequest> req = new Req<>();
        req.setHeader(new Req.Header());
        req.setResBody(userRequest);

        RequestEntity<Req<UserRequest>> requestEntity = RequestEntity
                .post(uri)
                .contentType(MediaType.APPLICATION_JSON)
                .header("x-authorization", "abcd")
                .header("custom-header", "fffff")
                .body(req);

        RestTemplate restTemplate = new RestTemplate();
        
        // 제네릭 타입에는 클래스를 붙일수 없다. Req<UserResponse>.Class를 대체해 사용
        // ResponseEntity<Req<UserResponse>> response 로 선언하였으므로
        // new ParameterizedTypeReference<>(){} 로 사용해도 무관
        ResponseEntity<Req<UserResponse>> response =
                restTemplate.exchange(requestEntity, new ParameterizedTypeReference<Req<UserResponse>>() {
                });

        return response.getBody();
    }
}

 

서버

Req.java

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Req<T> {
    private Header header;
    private T resBody;

    @Data
    @NoArgsConstructor
    @AllArgsConstructor
    public static class Header {
        private String responseCode;
    }
}

User.java

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class User {
    private String name;
    private int age;

}

ServerApiController.java

import com.example.server.dto.Req;
import com.example.server.dto.User;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.*;

@Slf4j
@RestController
@RequestMapping("/api/server")
public class ServerApiController {

    @PostMapping("/user/{userId}/name/{userName}")
    public Req<User> post(
            //HttpEntity<String> entity,
            @RequestBody Req<User> user,
            @PathVariable int userId,
            @PathVariable String userName,
            @RequestHeader("x-authorization") String authorization,
            @RequestHeader("custom-header") String customHeader
    ) {
        //log.info("req : {}", entity.getBody());
        log.info("userId : {}, userName : {}", userId, userName);
        log.info("authorization : {}, custom : {}", authorization, customHeader);
        log.info("client req : {}", user);

        Req<User> response = new Req<>();
        response.setHeader(
                new Req.Header()
        );
        response.setResBody(user.getResBody());
        return response;
    }
}