jpablog : kakao login api - access token

jpablog/src/main/java/com/example/jpablog/controller/api/UserApiController.java

@@ -1,17 +1,18 @@
 package com.example.jpablog.controller.api;
 
-import com.example.jpablog.config.auth.PrincipalDetail;
-import com.example.jpablog.config.auth.PrincipalDetailService;
 import com.example.jpablog.dto.ResponseDto;
 import com.example.jpablog.model.User;
 import com.example.jpablog.service.UserService;
 import lombok.RequiredArgsConstructor;
-import org.springframework.http.HttpStatus;
+import org.springframework.http.*;
 import org.springframework.security.authentication.AuthenticationManager;
 import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
 import org.springframework.security.core.Authentication;
 import org.springframework.security.core.context.SecurityContextHolder;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
 import org.springframework.web.bind.annotation.*;
+import org.springframework.web.client.RestTemplate;
 
 import java.security.Principal;
 
@@ -41,6 +42,31 @@ public class UserApiController {
         return new ResponseDto<>(-1, HttpStatus.BAD_REQUEST.value());
     }
 
+    @GetMapping("/auth/kakao/callback")
+    public String kakaoCallback(String code) {
+        // Retrofit2, OkHttp, RestTemplate, HttpsURLConnection 등이 있음
+        RestTemplate rt = new RestTemplate();
+        HttpHeaders headers = new HttpHeaders();
+        headers.add("Content-type", "application/x-www-form-urlencoded; charset=utf-8");
+
+        MultiValueMap<String, String> params = new LinkedMultiValueMap<>();
+        params.add("grant_type", "authorization_code");
+        params.add("client_id", "e40b81f26358aa250b10a59dc8f3aa62");
+        params.add("redirect_uri", "http://localhost:8080/auth/kakao/callback");
+        params.add("code", code);
+
+        HttpEntity<MultiValueMap<String, String>> kakaoTokenRequest =
+                new HttpEntity<>(params, headers);
+
+        ResponseEntity<String> response = rt.exchange(
+                "https://kauth.kakao.com/oauth/token",
+                HttpMethod.POST,
+                kakaoTokenRequest,
+                String.class
+        );
+
+        return "카카오 토큰 요청 완료" + response;
+    }
     /*// 기본 로그인
     @PostMapping("/user/login")
     public ResponseDto<Integer> login(@RequestBody User user, HttpSession session) {

jpablog/src/main/webapp/WEB-INF/views/user/loginForm.jsp

@@ -13,6 +13,7 @@
             <input name="password" type="password" class="form-control" placeholder="Enter password" id="password">
         </div>
         <button id="btn-login" type="submit" class="btn btn-primary">로그인</button>
+        <a href="https://kauth.kakao.com/oauth/authorize?client_id=e40b81f26358aa250b10a59dc8f3aa62&redirect_uri=http://localhost:8080/auth/kakao/callback&response_type=code&scope=account_email"><img height="38px" src="/images/kakao_login_medium.png" alt="kakao_login_button"/> </a>
     </form>
 </div>