[Feat]: 유저 닉네임 조회 API 구현

src/main/java/io/sobok/SobokSobok/auth/application/UserService.java

@@ -1,7 +1,12 @@
 package io.sobok.SobokSobok.auth.application;
 
+import io.sobok.SobokSobok.auth.application.util.UserServiceUtil;
 import io.sobok.SobokSobok.auth.domain.User;
 import io.sobok.SobokSobok.auth.infrastructure.UserRepository;
+import io.sobok.SobokSobok.auth.ui.dto.UsernameResponse;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
@@ -17,4 +22,24 @@ public Boolean duplicateNickname(String username) {
 
         return userRepository.existsByUsername(username);
     }
+
+    @Transactional
+    public List<UsernameResponse> getUsername(Long userId, String username) {
+        UserServiceUtil.existsUserById(userRepository, userId);
+
+        Optional<User> optionalMember = userRepository.findByUsername(username);
+
+        List<UsernameResponse> result = new ArrayList<>();
+
+        optionalMember.ifPresent(
+            member -> result.add(UsernameResponse.builder()
+                .memberId(member.getId())
+                .memberName(member.getUsername())
+                .deviceOS(member.getSocialInfo().getSocialType())
+                .selfCheck(member.getId().equals(userId))
+                .build())
+        );
+
+        return result;
+    }
 }

src/main/java/io/sobok/SobokSobok/auth/infrastructure/UserRepository.java

@@ -13,4 +13,6 @@ public interface UserRepository extends JpaRepository<User, Long> {
     Boolean existsBySocialInfoSocialId(String socialId);
 
     Boolean existsByUsername(String username);
+
+    Optional<User> findByUsername(String username);
 }

src/main/java/io/sobok/SobokSobok/auth/ui/UserController.java

@@ -1,13 +1,17 @@
 package io.sobok.SobokSobok.auth.ui;
 
 import io.sobok.SobokSobok.auth.application.UserService;
+import io.sobok.SobokSobok.auth.domain.User;
+import io.sobok.SobokSobok.auth.ui.dto.UsernameResponse;
 import io.sobok.SobokSobok.common.dto.ApiResponse;
 import io.sobok.SobokSobok.exception.SuccessCode;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.tags.Tag;
+import java.util.List;
 import lombok.RequiredArgsConstructor;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.annotation.AuthenticationPrincipal;
 import org.springframework.web.bind.annotation.*;
 
 @RestController
@@ -32,4 +36,21 @@ public ResponseEntity<ApiResponse<Boolean>> isNicknameDuplicate(@RequestParam fi
                         userService.duplicateNickname(username)
                 ));
     }
+
+    @GetMapping("/search")
+    @Operation(
+        summary = "유저 닉네임 조회 API 메서드",
+        description = "공유 멤버(유저) 닉네임을 조회하는 메서드입니다."
+    )
+    public ResponseEntity<ApiResponse<List<UsernameResponse>>> getUsername(
+        @AuthenticationPrincipal User user,
+        @RequestParam final String username
+    ) {
+        return ResponseEntity
+            .status(HttpStatus.OK)
+            .body(ApiResponse.success(
+                SuccessCode.GET_USERNAME_SUCCESS,
+                userService.getUsername(user.getId(), username)
+            ));
+    }
 }

src/main/java/io/sobok/SobokSobok/auth/ui/dto/UsernameResponse.java

@@ -0,0 +1,14 @@
+package io.sobok.SobokSobok.auth.ui.dto;
+
+import io.sobok.SobokSobok.auth.domain.SocialType;
+import lombok.Builder;
+
+@Builder
+public record UsernameResponse(
+    Long memberId,
+    String memberName,
+    SocialType deviceOS,
+    Boolean selfCheck
+) {
+
+}

src/main/java/io/sobok/SobokSobok/exception/SuccessCode.java

@@ -17,6 +17,7 @@ public enum SuccessCode {
 
     // user
     NICKNAME_CHECK_SUCCESS(HttpStatus.OK, "닉네임 중복 확인에 성공했습니다."),
+    GET_USERNAME_SUCCESS(HttpStatus.OK, "유저 이름 조회에 성공했습니다."),
 
     // pill
     ADD_PILL_SUCCESS(HttpStatus.CREATED, "약 추가에 성공했습니다."),