Java Encoder & Decoder

A simple Java-based Encoder and Decoder project for converting plain text into encoded format and decoding it back into readable text.

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Features

• Encode plain text into a secure format
• Decode encoded text back to original text
• Easy-to-use command-line interface
• Lightweight and beginner-friendly Java project
• Supports custom encoding logic

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Technologies Used

• Java
• OOP Concepts
• File Handling (optional)
• Command Line Interface

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Project Structure

EncoderDecoder/
│
├── src/
│   ├── Encoder.java
│   ├── Decoder.java
│   └── Main.java
│
├── README.md
└── LICENSE

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Requirements

Before running the project, make sure you have:

• Java JDK 8 or above
• Any Java IDE (IntelliJ IDEA, Eclipse, VS Code)
• Command Prompt / Terminal

Check Java installation:

java -version
javac -version

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How to Run

1. Clone the Repository

git clone https://github.com/your-username/EncoderDecoder.git
cd EncoderDecoder

2. Compile the Java Files

javac src/*.java

3. Run the Program

java src/Main

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Example

Input

Hello World

Encoded Output

Khoor Zruog

Decoded Output

Hello World

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Sample Encoder Logic

Example using Caesar Cipher:

public class Encoder {
    public static String encode(String text, int shift) {
        StringBuilder result = new StringBuilder();

        for (char ch : text.toCharArray()) {
            if (Character.isLetter(ch)) {
                char base = Character.isUpperCase(ch) ? 'A' : 'a';
                ch = (char) ((ch - base + shift) % 26 + base);
            }
            result.append(ch);
        }

        return result.toString();
    }
}

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Sample Decoder Logic

public class Decoder {
    public static String decode(String text, int shift) {
        return Encoder.encode(text, 26 - shift);
    }
}

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Future Improvements

• GUI support using Java Swing or JavaFX
• File encryption/decryption
• Password-protected encoding
• Base64 and AES support
• Web version using Spring Boot

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Contributing

Contributions are welcome.

1. Fork the repository
2. Create a new branch
3. Commit your changes
4. Push to your branch
5. Open a Pull Request

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License

This project is licensed under the MIT License.

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Author

Developed using Java for learning and practice purposes.