[FEAT] WeeklyMission 서비스 생성

src/main/java/com/example/stepperbackend/service/WeeklyMissionService/WeeklyMissionService.java

@@ -0,0 +1,10 @@
+package com.example.stepperbackend.service.WeeklyMissionService;
+
+import com.example.stepperbackend.web.dto.WeeklyMissionDto;
+
+import java.util.List;
+
+public interface WeeklyMissionService {
+    WeeklyMissionDto.WeeklyMissionResponseDto getWeeklyMission(Long id);
+    //List<WeeklyMissionDto.WeeklyMissionResponseDto> getAllWeeklyMissions();
+}

src/main/java/com/example/stepperbackend/service/WeeklyMissionService/WeeklyMissionServiceImpl.java

@@ -0,0 +1,22 @@
+package com.example.stepperbackend.service.WeeklyMissionService;
+
+import com.example.stepperbackend.converter.WeeklyMissionConverter;
+import com.example.stepperbackend.domain.WeeklyMission;
+import com.example.stepperbackend.repository.WeeklyMissionRepository;
+import com.example.stepperbackend.web.dto.WeeklyMissionDto;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+
+@Service
+@RequiredArgsConstructor
+public class WeeklyMissionServiceImpl implements WeeklyMissionService {
+
+    private final WeeklyMissionRepository weeklyMissionRepository;
+
+    @Override
+    public WeeklyMissionDto.WeeklyMissionResponseDto getWeeklyMission(Long id) {
+        WeeklyMission weeklyMission = weeklyMissionRepository.findById(id)
+                .orElseThrow(() -> new RuntimeException("Weekly Mission not found"));
+        return WeeklyMissionConverter.toDto(weeklyMission);
+    }
+}