refactor: 모든 LocalDateTime, OffsetDateTime 타입 Instant 전환

common/web/src/main/kotlin/com/sangdol/common/web/config/JacksonConfig.kt

@@ -1,11 +1,8 @@
 package com.sangdol.common.web.config
 
-import com.fasterxml.jackson.core.JsonGenerator
 import com.fasterxml.jackson.databind.DeserializationFeature
-import com.fasterxml.jackson.databind.JsonSerializer
 import com.fasterxml.jackson.databind.ObjectMapper
-import com.fasterxml.jackson.databind.SerializerProvider
+import com.fasterxml.jackson.databind.SerializationFeature
-import com.fasterxml.jackson.databind.module.SimpleModule
 import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule
 import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateDeserializer
 import com.fasterxml.jackson.datatype.jsr310.deser.LocalTimeDeserializer
@@ -15,19 +12,13 @@ import com.fasterxml.jackson.module.kotlin.kotlinModule
 import org.springframework.context.annotation.Bean
 import org.springframework.context.annotation.Configuration
 import java.time.LocalDate
-import java.time.LocalDateTime
 import java.time.LocalTime
-import java.time.OffsetDateTime
-import java.time.ZoneId
 import java.time.format.DateTimeFormatter
 
 @Configuration
 class JacksonConfig {
 
     companion object {
-        private val ISO_OFFSET_DATE_TIME_FORMATTER: DateTimeFormatter =
-            DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ssXXX")
-
         private val LOCAL_TIME_FORMATTER: DateTimeFormatter =
             DateTimeFormatter.ofPattern("HH:mm")
     }
@@ -35,9 +26,9 @@ class JacksonConfig {
     @Bean
     fun objectMapper(): ObjectMapper = ObjectMapper()
         .registerModule(javaTimeModule())
-        .registerModule(dateTimeModule())
         .registerModule(kotlinModule())
         .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
+        .configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false)
 
     private fun javaTimeModule(): JavaTimeModule = JavaTimeModule()
         .addSerializer(
@@ -56,35 +47,4 @@ class JacksonConfig {
             LocalTime::class.java,
             LocalTimeDeserializer(LOCAL_TIME_FORMATTER)
         ) as JavaTimeModule
-
-    private fun dateTimeModule(): SimpleModule {
-        val simpleModule = SimpleModule()
-        simpleModule.addSerializer(LocalDateTime::class.java, LocalDateTimeSerializer())
-        simpleModule.addSerializer(OffsetDateTime::class.java, OffsetDateTimeSerializer())
-        return simpleModule
-    }
-
-    class LocalDateTimeSerializer : JsonSerializer<LocalDateTime>() {
-        override fun serialize(
-            value: LocalDateTime,
-            gen: JsonGenerator,
-            serializers: SerializerProvider
-        ) {
-            value.atZone(ZoneId.systemDefault())
-                .toOffsetDateTime()
-                .also {
-                    gen.writeString(it.format(ISO_OFFSET_DATE_TIME_FORMATTER))
-                }
-        }
-    }
-
-    class OffsetDateTimeSerializer : JsonSerializer<OffsetDateTime>() {
-        override fun serialize(
-            value: OffsetDateTime,
-            gen: JsonGenerator,
-            serializers: SerializerProvider
-        ) {
-            gen.writeString(value.format(ISO_OFFSET_DATE_TIME_FORMATTER))
-        }
-    }
 }

common/web/src/test/kotlin/com/sangdol/common/web/config/JacksonConfigTest.kt

@@ -7,10 +7,7 @@ import io.kotest.core.spec.style.FunSpec
 import io.kotest.matchers.shouldBe
 import io.kotest.matchers.string.shouldContain
 import java.time.LocalDate
-import java.time.LocalDateTime
 import java.time.LocalTime
-import java.time.OffsetDateTime
-import java.time.ZoneOffset
 
 class JacksonConfigTest : FunSpec({
 
@@ -55,38 +52,4 @@ class JacksonConfigTest : FunSpec({
             }.message shouldContain "Text '$hour:$minute:$sec' could not be parsed"
         }
     }
-
-    context("Long 타입은 문자열로 (역)직렬화된다.") {
-        val number = 1234567890L
-        val serialized: String = objectMapper.writeValueAsString(number)
-        val deserialized: Long = objectMapper.readValue(serialized, Long::class.java)
-
-        test("Long 직렬화") {
-            serialized shouldBe "$number"
-        }
-
-        test("Long 역직렬화") {
-            deserialized shouldBe number
-        }
-    }
-
-    context("OffsetDateTime은 ISO 8601 형식으로 직렬화된다.") {
-        val date = LocalDate.of(2025, 7, 14)
-        val time = LocalTime.of(12, 30, 0)
-        val dateTime = OffsetDateTime.of(date, time, ZoneOffset.ofHours(9))
-        val serialized: String = objectMapper.writeValueAsString(dateTime)
-
-        test("OffsetDateTime 직렬화") {
-            serialized shouldBe "\"2025-07-14T12:30:00+09:00\""
-        }
-    }
-
-    context("LocalDateTime은 ISO 8601 형식으로 직렬화된다.") {
-        val dateTime = LocalDateTime.of(2025, 7, 14, 12, 30, 0)
-        val serialized: String = objectMapper.writeValueAsString(dateTime)
-
-        test("LocalDateTime 직렬화") {
-            serialized shouldBe "\"2025-07-14T12:30:00+09:00\""
-        }
-    }
 })

frontend/src/pages/admin/AdminSchedulePage.tsx

@@ -1,5 +1,5 @@
-import { isLoginRequiredError } from '@_api/apiClient';
+import {isLoginRequiredError} from '@_api/apiClient';
-import type { AuditInfo } from '@_api/common/commonTypes';
+import type {AuditInfo} from '@_api/common/commonTypes';
 import {
     createSchedule,
     deleteSchedule,
@@ -7,15 +7,16 @@ import {
     fetchScheduleAudit,
     updateSchedule
 } from '@_api/schedule/scheduleAPI';
-import { type AdminScheduleSummaryResponse, ScheduleStatus, } from '@_api/schedule/scheduleTypes';
+import {type AdminScheduleSummaryResponse, ScheduleStatus,} from '@_api/schedule/scheduleTypes';
-import { getStores } from '@_api/store/storeAPI';
+import {getStores} from '@_api/store/storeAPI';
-import { type SimpleStoreResponse } from '@_api/store/storeTypes';
+import {type SimpleStoreResponse} from '@_api/store/storeTypes';
-import { fetchActiveThemes } from '@_api/theme/themeAPI';
+import {fetchActiveThemes} from '@_api/theme/themeAPI';
-import { DifficultyKoreanMap, type SimpleActiveThemeResponse, type ThemeInfoResponse } from '@_api/theme/themeTypes';
+import {DifficultyKoreanMap, type SimpleActiveThemeResponse, type ThemeInfoResponse} from '@_api/theme/themeTypes';
-import { useAdminAuth } from '@_context/AdminAuthContext';
+import {useAdminAuth} from '@_context/AdminAuthContext';
 import '@_css/admin-schedule-page.css';
-import React, { Fragment, useEffect, useState } from 'react';
+import {formatDisplayDateTime} from '@_util/DateTimeFormatter';
-import { useLocation, useNavigate } from 'react-router-dom';
+import React, {Fragment, useEffect, useState} from 'react';
+import {useLocation, useNavigate} from 'react-router-dom';
 
 const getScheduleStatusText = (status: ScheduleStatus): string => {
     switch (status) {
@@ -332,10 +333,10 @@ const AdminSchedulePage: React.FC = () => {
                                                             <h4 className="audit-title">감사 정보</h4>
                                                             <div className="audit-body">
                                                                 <p>
-                                                                    <strong>생성일:</strong> {new Date(detailedSchedules[schedule.id].audit!.createdAt).toLocaleString()}
+                                                                    <strong>생성일:</strong> {formatDisplayDateTime(detailedSchedules[schedule.id].audit!.createdAt)}
                                                                 </p>
                                                                 <p>
-                                                                    <strong>수정일:</strong> {new Date(detailedSchedules[schedule.id].audit!.updatedAt).toLocaleString()}
+                                                                    <strong>수정일:</strong> {formatDisplayDateTime(detailedSchedules[schedule.id].audit!.updatedAt)}
                                                                 </p>
                                                                 <p>
                                                                     <strong>생성자:</strong> {detailedSchedules[schedule.id].audit!.createdBy.name}({detailedSchedules[schedule.id].audit!.createdBy.id})

frontend/src/pages/admin/AdminStorePage.tsx

@@ -1,17 +1,18 @@
-import { isLoginRequiredError } from '@_api/apiClient';
+import {isLoginRequiredError} from '@_api/apiClient';
-import { fetchSidoList, fetchSigunguList } from '@_api/region/regionAPI';
+import {fetchSidoList, fetchSigunguList} from '@_api/region/regionAPI';
-import type { SidoResponse, SigunguResponse } from '@_api/region/regionTypes';
+import type {SidoResponse, SigunguResponse} from '@_api/region/regionTypes';
-import { createStore, deleteStore, getStoreDetail, getStores, updateStore } from '@_api/store/storeAPI';
+import {createStore, deleteStore, getStoreDetail, getStores, updateStore} from '@_api/store/storeAPI';
 import {
     type SimpleStoreResponse,
     type StoreDetailResponse,
     type StoreRegisterRequest,
     type UpdateStoreRequest
 } from '@_api/store/storeTypes';
-import { useAdminAuth } from '@_context/AdminAuthContext';
+import {useAdminAuth} from '@_context/AdminAuthContext';
 import '@_css/admin-store-page.css';
-import React, { Fragment, useEffect, useState } from 'react';
+import {formatDisplayDateTime} from '@_util/DateTimeFormatter';
-import { useLocation, useNavigate } from 'react-router-dom';
+import React, {Fragment, useEffect, useState} from 'react';
+import {useLocation, useNavigate} from 'react-router-dom';
 
 const AdminStorePage: React.FC = () => {
     const [stores, setStores] = useState<SimpleStoreResponse[]>([]);
@@ -297,10 +298,10 @@ const AdminStorePage: React.FC = () => {
                                                                         코드:</strong> {detailedStores[store.id].region.code}
                                                                     </p>
                                                                     <p>
-                                                                        <strong>생성일:</strong> {new Date(detailedStores[store.id].audit.createdAt).toLocaleString()}
+                                                                        <strong>생성일:</strong> {formatDisplayDateTime(detailedStores[store.id].audit.createdAt)}
                                                                     </p>
                                                                     <p>
-                                                                        <strong>수정일:</strong> {new Date(detailedStores[store.id].audit.updatedAt).toLocaleString()}
+                                                                        <strong>수정일:</strong> {formatDisplayDateTime(detailedStores[store.id].audit.updatedAt)}
                                                                     </p>
                                                                     <p>
                                                                         <strong>생성자:</strong> {detailedStores[store.id].audit.createdBy.name}({detailedStores[store.id].audit.createdBy.id})

frontend/src/pages/admin/AdminThemeEditPage.tsx

@@ -9,7 +9,8 @@ import {
 import React, {useEffect, useState} from 'react';
 import {useLocation, useNavigate, useParams} from 'react-router-dom';
 import '@_css/admin-theme-edit-page.css';
-import type { AuditInfo } from '@_api/common/commonTypes';
+import type {AuditInfo} from '@_api/common/commonTypes';
+import {formatDisplayDateTime} from '@_util/DateTimeFormatter';
 
 interface ThemeFormData {
     name: string;
@@ -256,8 +257,8 @@ const AdminThemeEditPage: React.FC = () => {
                     <div className="audit-info">
                         <h4 className="audit-title">감사 정보</h4>
                         <div className="audit-body">
-                            <p><strong>생성일:</strong> {new Date(auditInfo.createdAt).toLocaleString()}</p>
+                            <p><strong>생성일:</strong> {formatDisplayDateTime(auditInfo.createdAt)}</p>
-                            <p><strong>수정일:</strong> {new Date(auditInfo.updatedAt).toLocaleString()}</p>
+                            <p><strong>수정일:</strong> {formatDisplayDateTime(auditInfo.updatedAt)}</p>
                             <p><strong>생성자:</strong> {auditInfo.createdBy.name}</p>
                             <p><strong>수정자:</strong> {auditInfo.updatedBy.name}</p>
                         </div>