An Android application demonstrating localization, data-driven design patterns, lifecycle-aware components and modern Android development best practices. The app serves as a comprehensive travel guide to Toyama Prefecture, Japan, offering tourist information across three languages: English, Japanese, and Simplified Chinese.
| Home Screen | Travel View | Event Page |
|---|---|---|
 |
 |
 |
Instead of maintaining duplicate codebases for English (en), Japanese (ja), and Chinese (zh), the application implements the custom LocalizationManager which:
- Automatically detects the system default locale.
- Allows seamless switching between English, Japanese, and Chinese at runtime.
- Persists user preferences using
SharedPreferences. - Recreates application context using dynamic configuration locale override.
Instead of hardcoding layout details, sights are defined dynamically in localized JSON files (assets/kankou1jp.json, assets/kankou1en.json, etc.). Sights are categorized by:
- Attractions (観光地): Scenic spots across three key regions: Himi/Tonami area, Toyama City area, and Kurobe/Tateyama area.
- Food (食事): Local gourmet recommendations by region.
- Events (イベント): Festivals and local events.
- Culture (文化): Cultural workshops, museums, and historical activities.
- Etiquette (マナー): Travel manners and dining rules.
- Hot Springs (温泉): Hot spring baths and spa resorts.
- Transportation (電車): Transit routes and train systems.
- ViewModel Cache Layer: Sights data parsed from JSON is cached dynamically in
CategoryRepositoryusing a memory cache map. - Lifecycle Awareness: ViewModels handle data updates using
LiveDatato prevent visual bugs when rotating screens or moving across activities. - Fail-safe Fallbacks: Missing images or invalid resource references resolve gracefully to
ic_placeholder.xmlinstead of causing app crashes.
The project underwent a significant architectural overhaul, refactoring it from a code-duplicated prototype to a production-ready portfolio application.
| Metric | Before Refactoring | After Refactoring | Architectural Impact |
|---|---|---|---|
| Code Duplication | ~75% | <15% | Eliminates redundant classes and code maintenance overhead. |
| Activity Count | 27 Activities | 10 Activities | High maintainability, unified entry points, and dynamic loading. |
| Localization Method | 3x Parallel Code Branches (e.g. MainActivityJp, MainActivityEn, MainActivityCn) |
Locale-based Resource Resolution | Proper Android system resource qualifiers with standard system locale support. |
| Data Loading | Hardcoded JSON filenames inside Views | Repository Pattern with Caching | Centralized data logic, memory cache to avoid unnecessary asset parsing. |
| State Preservation | Reset on screen rotation | ViewModel & LiveData | State is preserved across configuration changes (e.g., orientation). |
| Accessibility (a11y) | Missing descriptions | Fully Accessible Views | Dynamic content descriptions and announcements for screen readers. |
- Language: Kotlin (100%)
- Architecture Pattern: MVVM (Model-View-ViewModel) + Repository Pattern
- UI & Views: ViewBinding, Material Design 3, Fragments,
RecyclerView - Data Serialization: Kotlinx Serialization (JSON Parsing)
- Localization: Dynamic runtime locale shifting, Android locale qualifiers (
values-ja/,values-zh/), and SharedPreferences persistence. - Tests: Local JUnit tests & Android Instrumentation tests (Espresso).
- Optimizations: ProGuard/R8 minification enabled for release builds.
├── app/
│ ├── src/
│ │ ├── main/
│ │ │ ├── java/com/example/travelapp/
│ │ │ │ ├── data/
│ │ │ │ │ ├── CategoryConstants.kt # Core identifiers & layout resource mapping
│ │ │ │ │ └── CategoryRepository.kt # Cached JSON parsing with error recovery fallbacks
│ │ │ │ ├── util/
│ │ │ │ │ └── LocalizationManager.kt # Singleton runtime locale switcher
│ │ │ │ ├── viewmodel/
│ │ │ │ │ ├── MainViewModel.kt # UI state for MainActivity
│ │ │ │ │ ├── ListViewModel.kt # UI state for ListFragment
│ │ │ │ │ └── DetailViewModel.kt # UI state for DetailFragment
│ │ │ │ ├── MainActivity.kt # Gateway dashboard screen
│ │ │ │ ├── ChooseActivity.kt # Regional filter screen (Himi, Toyama, Kurobe)
│ │ │ │ ├── ListActivity.kt # Dynamic listings host activity
│ │ │ │ ├── ListFragment.kt # Multi-region sights recycler list view
│ │ │ │ ├── DetailActivity.kt # Dynamic swipe detail host activity
│ │ │ │ ├── DetailFragment.kt # Individual tourist spot information view
│ │ │ │ ├── MannerActivity.kt # Etiquette guide activity
│ │ │ │ ├── SightAdapter.kt # RecyclerView list adapter with ViewBinding
│ │ │ │ └── Sight.kt # Kotlinx-Serializable data class representation
│ │ │ ├── assets/ # Multilingual JSON content databases
│ │ │ └── res/ # Localized string and theme resource qualifiers
│ │ └── test/ # Local unit testing suites
│ │ └── androidTest/ # UI & integration tests
│ └── build.gradle.kts # App build configuration & dependencies
└── settings.gradle.kts # Module definition
- JDK 17 or higher
- Android Studio Jellyfish / Koala (or newer)
- Gradle 8.13 (included via wrapper)
To build the application locally, use the following commands from the root directory:
# Clean the project build directories
./gradlew clean
# Build the debug APK
./gradlew assembleDebug
# Build and optimize release APK (with ProGuard/R8 shrinking enabled)
./gradlew assembleReleaseEnsure all behaviors are functional by running:
# Execute local unit tests (caching logic, parsing, utility classes)
./gradlew test
# Execute Android instrumentation/Espresso UI tests (running device or emulator needed)
./gradlew connectedAndroidTest