HuffmanZip

HuffmanZip is a Java program that implements Huffman Encoding and Decoding for text files. It compresses files to reduce storage space and allows lossless decompression back to the original file.

The project demonstrates:

• File I/O handling
• Tree data structures
• Bit-level operations
• Priority queue usage in Java

HuffmanZip is perfect for users who want to save storage space or experiment with data compression, while developers can explore Huffman Tree, BitStream, and file handling in Java.

Getting Started

Follow these instructions to run HuffmanZip program on your machine:

Prerequisites

You’ll need:

• Java JDK 11+ (includes both):

  • Compiler (javac) – to compile Java source files
  • Runtime (java) – to run compiled programs

• A terminal or command prompt (macOS/Linux or Command Prompt/PowerShell on Windows)

Check that Java JDK is installed:

java -version   # checks the Java runtime

and

javac -version  # checks the Java compiler

Installing

1. Clone this repository and Navigate to the project directory:

git clone https://github.com/soikat27/huffman-zip.git

cd huffman-zip

Running the program

Option 1: Compile and Run:

1. Create a folder for compiled classes:

mkdir bin

2. Compile all .java files:

javac -d bin src/huffman/*.java src/huffmanzip/*.java src/utils/*.java

3. Run the main program

   (a sample test file is provided in ./test/resource dir for program test):

• Encode:

java -cp bin huffmanzip.HuffmanZip -encode <your_file>

• Decode: **For decoding, <your_file> must be a .hz compressed file.

java -cp bin huffmanzip.HuffmanZip -decode <your_file>

** Replace <your_file> with your own file.

Option 2: Run with the Prebuilt JAR:

Not in a mood to compile manually? use the JAR located in dist/ !

• Encode:

java -jar dist/HuffmanZip.jar -encode <your_file>

• Decode: **must use .hz file

java -jar dist/HuffmanZip.jar -decode <your_file>

** Replace <your_file> with your own file.

Running Tests

JUnit tests are available in the test/ folder.

1. Compile JUnit tests:

javac -cp "bin:junit-4.13.2.jar:hamcrest-core-1.3.jar" -d bin test/huffman/*.java

2. Run JUnit test classes:

java -cp "bin:junit-4.13.2.jar:hamcrest-core-1.3.jar" org.junit.runner.JUnitCore huffman.HNodeTest

java -cp "bin:junit-4.13.2.jar:hamcrest-core-1.3.jar" org.junit.runner.JUnitCore huffman.HuffmanTreeTest

Deployment

There’s no special deployment needed. Use the ready-to-go Jar or Compile the program with Java and run it locally from the terminal as instructed above.

Built With

• Java 11+ – core language
• JUnit 4 – for automated testing
• BitInputStream / BitOutputStream – custom utilities for bit-level operations
• JavaDoc – documentation generated in doc/ (see doc/index.html)

Contributing

Contributions are welcome! You can:

• Submit bug reports or feature requests via GitHub Issues

• Fork the repository and submit pull requests for improvements

Author

• Soikat Saha – initial development

License

This project is licensed under the Apache 2.0 License - see the LICENSE file for details

Acknowledgments

• Inspired by Huffman Coding Algorithm – David A. Huffman
• Special thanks to Professor Ilinkin for guidance on data structures
• Utility functions provided in BitInputStream & BitOutputStream
• Thanks to the Java open-source community for helpful resources