feat(java): set up backend scaffolding with basic CRUD

.gitattributes

@@ -0,0 +1,8 @@
+# Git Attributes for docs-sample-apps
+# Marks auto-generated files that are committed to version control
+# so they're collapsed in GitHub PR diffs and excluded from code review
+
+# Maven Wrapper - Auto-generated by Apache Maven (committed to git)
+# See: https://maven.apache.org/wrapper/
+server/java-spring/mvnw linguist-generated=true
+server/java-spring/mvnw.cmd linguist-generated=true

.gitignore

@@ -0,0 +1,54 @@
+# =============================================================================
+# Root .gitignore for MongoDB Sample Apps Monorepo
+# =============================================================================
+# This file contains patterns common to all projects in the monorepo.
+# Backend-specific patterns are defined in each backend's .gitignore file.
+# =============================================================================
+
+# Environment Variables (Global)
+.env
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+!.env.example
+
+# Operating System Files
+.DS_Store
+Thumbs.db
+
+# IDE and Editor Files (Global)
+.idea/
+.vscode/
+*.swp
+*.swo
+*.swn
+*.bak
+*.tmp
+*.iml
+.project
+.classpath
+.settings/
+*.sublime-project
+*.sublime-workspace
+
+# Logs (Global)
+logs/
+*.log
+
+# Temporary Files (Global)
+*.tmp
+*.temp
+.cache/
+
+# Node.js (Global - applies to all Node.js projects)
+node_modules/
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+.pnpm-debug.log*
+
+# Test Coverage (Global)
+coverage/
+*.lcov
+.nyc_output

server/express/.gitignore

@@ -23,4 +23,5 @@ coverage/
 .npm
 
 # macOS
-.DS_Store
+.DS_Store
+

server/java-spring/.env.example

@@ -0,0 +1,13 @@
+# MongoDB Connection
+# Replace with your MongoDB Atlas connection string or local MongoDB URI
+MONGODB_URI=mongodb+srv://username:password@cluster.mongodb.net/?retryWrites=true&w=majority
+
+# Server Configuration
+# Port on which the Spring Boot application will run
+PORT=3001
+
+# CORS Configuration
+# Allowed origin for cross-origin requests (frontend URL)
+# For multiple origins, separate with commas
+CORS_ORIGIN=http://localhost:3000
+

server/java-spring/.gitignore

@@ -0,0 +1,64 @@
+# Java/Spring Boot - Specific Ignores
+# Common patterns
+.env
+.DS_Store
+
+#Cache
+.cache/
+
+# Compiled Files
+*.class
+*.ctxt
+.mtj.tmp/
+
+# Package Files
+*.jar
+*.war
+*.nar
+*.ear
+
+# Crash Logs
+hs_err_pid*
+replay_pid*
+
+# Maven
+target/
+pom.xml.tag
+pom.xml.releaseBackup
+pom.xml.versionsBackup
+pom.xml.next
+release.properties
+dependency-reduced-pom.xml
+buildNumber.properties
+.mvn/timing.properties
+.mvn/wrapper/maven-wrapper.jar
+
+# IntelliJ IDEA
+*.iws
+*.iml
+*.ipr
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+# Eclipse
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+# NetBeans
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+# Spring Boot
+spring-boot-devtools.properties

server/java-spring/.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,13 @@
+# Maven Wrapper Configuration
+# Use ./mvnw instead of mvn to automatically download and use the specified Maven version.
+
+# Maven Wrapper version (not the Maven version itself)
+wrapperVersion=3.3.4
+
+# Download only Maven binaries (recommended for most projects)
+distributionType=only-script
+
+# Maven version to download - pins everyone to Maven 3.8.6 for consistent builds
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.8.6/apache-maven-3.8.6-bin.zip
+
+# Usage: ./mvnw clean install (Unix/macOS) or mvnw.cmd clean install (Windows)

server/java-spring/README.md

@@ -0,0 +1,201 @@
+# sample-app-java-mflix (INTERNAL)
+
+A Spring Boot REST API demonstrating MongoDB CRUD operations using Spring Data MongoDB with the sample_mflix database.
+
+## Overview
+
+This application provides a REST API for managing movie data from MongoDB's sample_mflix database. It demonstrates:
+
+- Spring Data MongoDB for simplified data access
+- CRUD operations (Create, Read, Update, Delete)
+- Text search functionality
+- Filtering, sorting, and pagination
+- Comprehensive error handling
+- API documentation with Swagger/OpenAPI
+- MongoTemplate for complex queries
+
+## Prerequisites
+
+- Java 21 or later
+- Maven 3.6 or later
+- MongoDB Atlas account or local MongoDB instance with sample_mflix database
+
+## Project Structure
+
+```
+server/java-spring/
+├── src/
+│   ├── main/
+│   │   ├── java/com/mongodb/samplemflix/
+│   │   │   ├── SampleMflixApplication.java    # Main application class
+│   │   │   ├── config/                         # Configuration classes
+│   │   │   │   ├── MongoConfig.java           # MongoDB client configuration
+│   │   │   │   ├── CorsConfig.java            # CORS configuration
+│   │   │   │   └── DatabaseVerification.java  # Startup database verification
+│   │   │   ├── controller/                     # REST controllers
+│   │   │   ├── service/                        # Business logic layer
+│   │   │   ├── repository/                     # Data access layer
+│   │   │   ├── model/                          # Domain models and DTOs
+│   │   │   ├── exception/                      # Custom exceptions
+│   │   │   └── util/                           # Utility classes
+│   │   └── resources/
+│   │       └── application.properties          # Application configuration
+│   └── test/                                   # Test classes
+├── pom.xml                                     # Maven dependencies
+└── README.md
+```
+
+## Setup Instructions
+
+### 1. Clone the Repository
+
+```bash
+git clone <repository-url>
+cd server/java-spring
+```
+
+### 2. Configure Environment Variables
+
+Copy the example environment file and update with your MongoDB connection details:
+
+```bash
+cp .env.example .env
+```
+
+Edit `.env` and set your MongoDB connection string:
+
+```properties
+MONGODB_URI=mongodb+srv://username:password@cluster.mongodb.net/?retryWrites=true&w=majority
+PORT=3001
+CORS_ORIGIN=http://localhost:3000
+```
+
+> **Note**: This project uses [spring-dotenv](https://github.com/paulschwarz/spring-dotenv) to automatically load `.env` files, similar to Node.js applications. The `.env` file will be loaded automatically when you run the application.
+
+### 3. Load Sample Data
+
+If you haven't already, load the `sample_mflix` database into your MongoDB instance:
+
+- **MongoDB Atlas**: Use the "Load Sample Dataset" option in your cluster
+- **Local MongoDB**: Follow the [MongoDB sample data documentation](https://www.mongodb.com/docs/atlas/sample-data/)
+
+### 4. Build the Project
+
+```bash
+mvn clean install
+```
+
+### 5. Run the Application
+
+```bash
+mvn spring-boot:run
+```
+
+The application will start on `http://localhost:3001` (or the port specified in your `.env` file).
+
+## API Documentation
+
+Once the application is running, you can access:
+
+- **Swagger UI**: http://localhost:3001/swagger-ui.html
+- **OpenAPI JSON**: http://localhost:3001/api-docs
+
+## API Endpoints
+
+### Movies (✅ Implemented)
+
+- `GET /api/movies` - Get all movies (with filtering, sorting, pagination)
+- `GET /api/movies/{id}` - Get a single movie by ID
+- `POST /api/movies` - Create a new movie
+- `POST /api/movies/batch` - Create multiple movies
+- `PUT /api/movies/{id}` - Update a movie
+- `PATCH /api/movies` - Update multiple movies
+- `DELETE /api/movies/{id}` - Delete a movie
+- `DELETE /api/movies` - Delete multiple movies
+- `DELETE /api/movies/{id}/find-and-delete` - Find and delete a movie
+
+## Development
+
+### Running Tests
+
+```bash
+# Run all tests
+mvn test
+
+# Run tests with coverage
+mvn test jacoco:report
+```
+
+### Building for Production
+
+```bash
+mvn clean package
+java -jar target/sample-mflix-spring-1.0.0.jar
+```
+
+## Implementation Status
+
+### Completed Features
+
+- **Movies CRUD API** - Full create, read, update, delete operations
+- **Spring Data MongoDB** - Repository pattern with MongoTemplate for complex queries
+- **Text Search** - Full-text search on movie titles, plots, and genres
+- **Filtering & Pagination** - Query parameters for filtering, sorting, and pagination
+- **Custom Exception Handling** - Global exception handler with proper HTTP status codes
+- **Type-Safe DTOs** - Specific response types instead of generic Maps
+- **Unit Tests** - 35 tests covering service and controller layers
+- **OpenAPI Documentation** - Swagger UI available at `/swagger-ui.html`
+- **Database Verification** - Startup checks for database connectivity and indexes
+
+
+## Technology Stack
+
+- **Framework**: Spring Boot 3.5.7
+- **Java Version**: 21
+- **MongoDB**: Spring Data MongoDB 4.5.5
+- **Build Tool**: Maven
+- **API Documentation**: SpringDoc OpenAPI 2.8.13
+- **Testing**: JUnit 5, Mockito, Spring Boot Test
+
+## Educational Purpose
+
+This application is designed as an educational sample to demonstrate:
+
+1. How to use Spring Data MongoDB for simplified data access
+2. Best practices for Spring Boot REST API development
+3. Proper separation of concerns (Controller → Service → Repository)
+4. MongoDB CRUD operations and query patterns
+5. Error handling and validation in Spring Boot
+6. Using MongoTemplate for complex queries alongside Spring Data repositories
+
+## Troubleshooting
+
+### Connection Issues
+
+If you encounter connection issues:
+
+1. Verify your `MONGODB_URI` is correct
+2. Check that your IP address is whitelisted in MongoDB Atlas
+3. Ensure the sample_mflix database exists and contains data
+4. Check the application logs for detailed error messages
+
+### Build Issues
+
+If Maven build fails:
+
+1. Ensure you have Java 21 or later installed: `java -version`
+2. Ensure Maven is installed: `mvn -version`
+3. Clear Maven cache: `mvn clean`
+4. Try rebuilding: `mvn clean install`
+
+## License
+
+[TBD]
+
+## Contributing
+
+[TBD]
+
+## Issues
+
+[TBD]