CSV-to-Box

A Java-based utility that converts CSV files into separate Excel (.xlsx) files, grouped by customer name. This tool reads a semicolon-delimited CSV file and automatically splits the data into individual Excel workbooks based on the first column (customer name).

📋 Overview

CSV-to-Box processes large CSV files containing data for multiple customers and generates individual Excel files for each customer. This is particularly useful for:

• Distributing customer-specific reports
• Organizing data by client or entity
• Converting bulk CSV exports into manageable Excel files
• Automating report generation workflows

✨ Features

• Automatic Customer Grouping: Splits CSV data by customer name (first column)
• Excel Output: Generates .xlsx files using Apache POI
• Memory Efficient: Uses SXSSFWorkbook for streaming large datasets
• Header Preservation: Maintains CSV headers in each Excel file
• Semicolon Delimiter Support: Processes CSV files with semicolon (;) delimiters

🔧 Prerequisites

• Java: JDK 15 or higher
• Maven: For dependency management and building the project
• Apache POI: Automatically managed via Maven dependencies

📦 Installation

1. Clone the repository:

   git clone https://github.com/yourusername/CSV-to-Box.git
   cd CSV-to-Box/CsvToBox

2. Build the project with Maven:

   mvn clean install

3. Verify dependencies are installed: The pom.xml includes:

   • Apache POI 5.0.0
   • Apache POI OOXML 5.0.0

🚀 Usage

Basic Usage

1. Prepare your CSV file:

   • Ensure your CSV uses semicolon (;) as the delimiter
   • First column should contain customer names
   • First row should contain headers
   • Example format:

     CustomerName;Product;Quantity;Price
     ACME Corp;Widget A;100;50.00
     ACME Corp;Widget B;200;75.00
     TechCo;Gadget X;50;120.00
     

2. Update file paths in CSVtoExcel.java:

   // Input CSV file (line 19)
   new FileInputStream("C:\\Users\\willi\\Desktop\\test.csv")
   
   // Output directory (line 59)
   new FileOutputStream("C:\\Users\\willi\\Desktop\\Map\\test_" + name + ".xlsx")

3. Run the application:

   mvn exec:java -Dexec.mainClass="CSVtoExcel"

   Or compile and run directly:

   javac -cp "target/classes:target/dependency/*" src/main/java/CSVtoExcel.java
   java -cp "target/classes:target/dependency/*" CSVtoExcel

Output

The program will generate separate Excel files named:

• test_CustomerName1.xlsx
• test_CustomerName2.xlsx
• test_CustomerName3.xlsx
• etc.

Each file contains only the rows for that specific customer, with the original headers preserved.

📁 Project Structure

CSV-to-Box/
├── CsvToBox/
│   ├── src/
│   │   └── main/
│   │       └── java/
│   │           └── CSVtoExcel.java    # Main application logic
│   ├── pom.xml                         # Maven configuration
│   └── target/                         # Compiled classes and dependencies
└── README.md                           # This file

🔍 How It Works

1. Reading Phase:

   • Opens the CSV file and reads the header row
   • Reads data line by line
   • Groups consecutive rows with the same customer name

2. Grouping Logic:

   • Tracks the current customer name
   • Accumulates rows for each customer
   • When a new customer is encountered, writes the previous customer's data to Excel

3. Writing Phase:

   • Creates a new Excel workbook for each customer
   • Writes the header row
   • Populates data rows
   • Saves the file with the customer name in the filename

⚙️ Configuration

Changing the Delimiter

To use a different delimiter (e.g., comma instead of semicolon), modify the split pattern:

// Change from semicolon to comma
String[] values = scanner.nextLine().split(",");

Customizing Output Format

Modify the output path and filename pattern in the write() method:

workbook.write(new FileOutputStream("path/to/output/" + name + ".xlsx"));

🛠️ Technical Details

• Language: Java 15
• Build Tool: Maven
• Dependencies:
  • Apache POI 5.0.0 (Core Excel library)
  • Apache POI OOXML 5.0.0 (Excel 2007+ format support)
• Excel Format: XLSX (Office Open XML)
• Streaming: Uses SXSSFWorkbook for memory-efficient processing

⚠️ Known Limitations

• Hard-coded paths: Input and output file paths are currently hard-coded
• Delimiter: Only supports semicolon (;) delimiter
• Sorting requirement: CSV must be pre-sorted by customer name for optimal grouping
• Error handling: Limited exception handling for malformed CSV files

🔮 Future Improvements

• Add command-line arguments for input/output paths
• Support multiple delimiter types (comma, tab, pipe)
• Add configuration file support
• Implement proper logging
• Add progress indicators for large files
• Handle unsorted CSV files
• Add data validation and error reporting
• Support custom column selection for grouping
• Add unit tests

📝 License

This project is available for use under standard open-source practices.

🤝 Contributing

Contributions are welcome! Please feel free to submit issues or pull requests.

📧 Contact

For questions or support, please open an issue in the repository.

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Note: Remember to update the hard-coded file paths before running the application with your own data!