⚡ Advanced Java Decompiler

Next-generation Java bytecode decompilation with intelligent code reconstruction

Features • Installation • Usage • Architecture • Contributing

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📋 Table of Contents

• Overview
• Features
• Installation
• Usage
• Architecture
• API Configuration
• Advanced Features
• Screenshots
• Contributing
• License

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🌟 Overview

Advanced Java Decompiler is a professional-grade tool designed to reconstruct readable Java source code from compiled .class files. Built with a modern JavaFX interface and powered by multiple decompilation backends, it offers unparalleled accuracy and flexibility.

Why Choose This Decompiler?

Feature	Traditional Decompilers	Advanced Java Decompiler
Multiple Backends	❌ Single engine	✅ Groq, Gemini, OpenRouter, Heuristic
Streaming Output	❌ Wait for completion	✅ Real-time streaming
Batch Processing	⚠️ Limited	✅ JARs, ZIPs, Folders
Dependency Graph	❌ Not available	✅ Interactive visualization
Auto-Refactoring	❌ Raw output	✅ Modern Java patterns
Plugin System	❌ Fixed	✅ Groovy-based extensibility
Token Management	❌ Manual limits	✅ Auto-truncation & routing

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🚀 Features

🔧 Core Decompilation

• Multi-Backend Support

  • Groq: Fast, free-tier Llama 3.3 70B with streaming
  • Gemini: Google's advanced models (2.0 Flash, 2.5 Pro)
  • OpenRouter: Unified API access
  • Heuristic: Instant offline ASM-based decompilation

• Smart Auto Mode

  • Automatically selects optimal backend based on:
    • Code complexity analysis
    • Token limit estimation
    • Available API quotas

• Token Limit Management

  • Automatic bytecode truncation for large classes
  • Pre-flight token estimation
  • Intelligent routing to avoid rate limits

🎨 User Interface

• Professional Dark Theme

  • VSCode/IntelliJ-inspired design
  • High-contrast syntax highlighting
  • Smooth animations and transitions

• Dual View Modes

  • Single View: Decompiled code only
  • Diff View: Side-by-side bytecode ↔ source comparison

• Drag & Drop Support

  • .class files
  • .jar archives
  • .zip archives
  • Entire folders

📊 Advanced Analysis

• Interactive Dependency Graph

  • Visual class relationship mapping
  • Color-coded node types:
    • 🔵 Main class (cyan)
    • 🟠 Custom dependencies (orange)
    • ⚪ Java standard library (gray)
  • Hover highlighting
  • Circular layout algorithm

• Batch Processing

  • Decompile entire JARs in one click
  • Process folders recursively
  • Aggregate results with class separators

🛡️ Security & Privacy

• Secure Mode

  • Automatic secret redaction
  • Pattern-based detection:
    • API keys
    • Passwords
    • Tokens
    • Connection strings

• Local Processing

  • Heuristic mode runs 100% offline
  • No data sent to external servers

🔌 Extensibility

• Plugin System

  • Groovy-based post-processing scripts
  • Located in plugins/ folder
  • Example: deobfuscate.groovy for name recovery

• Auto-Refactoring Suggestions

  • Modern Java patterns (Streams, Records, Switch Expressions)
  • Inline comments with recommendations
  • Toggle on/off per session

📦 Export Options

• Project Structure Export
  • Maven-compatible layout
  • Gradle-compatible layout
  • Preserves package hierarchy
  • Generates build files

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💻 Installation

Prerequisites

Requirement	Version	Download
Java	17+	Oracle JDK
Gradle	7+	Included (Wrapper)
API Keys	Optional	See API Configuration

Quick Start

# Clone the repository
git clone https://github.com/Muhib-Mehdi/Advanced-Java-Decompiler.git
cd Advanced-Java-Decompiler

# Build the project
./gradlew build

# Run the application
./gradlew run

Windows Users

# Use gradlew.bat instead
.\gradlew.bat build
.\gradlew.bat run

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🎯 Usage

Basic Workflow

graph LR
    A[Upload .class] --> B{Select Mode}
    B -->|Auto| C[Smart Routing]
    B -->|Groq| D[Fast Streaming]
    B -->|Gemini| E[High Quality]
    B -->|Heuristic| F[Instant Offline]
    C --> G[Decompiled Code]
    D --> G
    E --> G
    F --> G
    G --> H{Export?}
    H -->|Yes| I[Maven/Gradle Project]
    H -->|No| J[Done]

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Decompilation Modes

Mode	Speed	Quality	Requires API	Best For
Auto (Smart)	⚡⚡⚡	⭐⭐⭐⭐	Optional	General use
Heuristic	⚡⚡⚡⚡⚡	⭐⭐⭐	No	Quick inspection
Groq	⚡⚡⚡⚡	⭐⭐⭐⭐	Yes	Real-time streaming
Gemini	⚡⚡⚡	⭐⭐⭐⭐⭐	Yes	Complex classes
OpenRouter	⚡⚡⚡	⭐⭐⭐⭐	Yes	Unified access

Step-by-Step Guide

1. Launch Application

   ./gradlew run

2. Select Decompilation Mode

   • Choose from dropdown menu
   • Auto mode recommended for beginners

3. Upload File

   • Drag & drop .class, .jar, .zip, or folder
   • Or click "Upload" button

4. Configure Options

   • ☑️ Secure Mode: Redact secrets
   • ☑️ Show Refactoring Tips: Get modernization suggestions

5. View Results

   • Toggle Diff View for bytecode comparison
   • Click Dependency Graph for class relationships
   • Use Export for project structure

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🏗️ Architecture

System Pipeline

graph TD
    A[JavaFX UI] --> B[Decompiler Pipeline]
    B --> C{Mode Selection}
    C -->|Auto| D[Model Orchestrator]
    C -->|Manual| E[Direct Backend]
    D --> F{Token Check}
    F -->|Within Limit| G[Groq/Gemini]
    F -->|Too Large| H[Gemini Fallback]
    E --> I[Selected Backend]
    G --> J[Plugin System]
    H --> J
    I --> J
    J --> K[Refactoring Advisor]
    K --> L[Output]

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Component Breakdown

Component	Responsibility	Technology
UI Layer	User interaction, visualization	JavaFX 21
Pipeline	Orchestration, caching	Java 17
Backends	Code reconstruction	Groq, Gemini, OpenRouter
Analyzer	Bytecode parsing	ASM 9.7
Plugins	Post-processing	Groovy 4.0
Security	Secret redaction	Regex patterns

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🔑 API Configuration

Supported Providers

Groq (Recommended - Free Tier)

Features:

• ✅ Free tier available
• ✅ Real-time streaming
• ✅ Fast response times
• ⚠️ 12,000 token limit (auto-handled)

Setup:

1. Get API key: console.groq.com/keys
2. Add to .env:

   GROQ_API_KEY=gsk_...

Google Gemini (High Quality)

Features:

• ✅ Free tier available
• ✅ Multiple model options (2.0 Flash, 2.5 Pro)
• ✅ High accuracy
• ⚠️ Rate limits apply

Setup:

1. Get API key: aistudio.google.com/app/apikey
2. Add to .env:

   GEMINI_API_KEY_1=...

OpenRouter (Unified Access)

Features:

• ✅ Access to multiple models
• ✅ Unified billing
• ⚠️ Paid service

Setup:

1. Get API key: openrouter.ai/keys
2. Add to .env:

   OPENROUTER_API_KEY=sk-or-...

Environment File Example

Create .env in project root:

# Choose ONE or more providers

# Groq (Fast & Free)
GROQ_API_KEY=gsk_your_key_here

# Gemini (High Quality)
GEMINI_API_KEY_1=your_key_here

# OpenRouter (Unified)
OPENROUTER_API_KEY=sk-or-your_key_here

Note: The application works offline with Heuristic mode even without API keys.

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🎓 Advanced Features

Plugin Development

Create custom post-processing plugins in plugins/ folder:

// plugins/custom-formatter.groovy
def transform(String code) {
    // Your transformation logic
    return code.replaceAll("oldPattern", "newPattern")
}

return this

Feedback System

The application includes a RAG-enhanced feedback system:

1. Rate decompilation accuracy (1-5 stars)
2. Provide corrections
3. System learns from feedback
4. Stored in ~/.aidecompiler/feedback.json

Keyboard Shortcuts

Shortcut	Action
Ctrl+O	Open file
Ctrl+S	Save output
Ctrl+D	Toggle diff view
Ctrl+G	Show dependency graph
Ctrl+E	Export project

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📸 Screenshots

Note: Screenshots showcase the professional dark theme and key features.

Main Interface

Dependency Graph

Diff View

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🤝 Contributing

Contributions are welcome! Please follow these guidelines:

Development Setup

# Fork and clone
git clone https://github.com/YOUR_USERNAME/Advanced-Java-Decompiler.git

# Create feature branch
git checkout -b feature/amazing-feature

# Make changes and test
./gradlew test

# Commit with conventional commits
git commit -m "feat: add amazing feature"

# Push and create PR
git push origin feature/amazing-feature

Code Style

• Follow Java naming conventions
• Use 4-space indentation
• Add JavaDoc for public methods
• Keep methods under 50 lines

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📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

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🙏 Acknowledgments

• ASM Framework - Bytecode manipulation
• JavaFX - Modern UI framework
• Groq - Fast LLM inference
• Google Gemini - Advanced language models

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📞 Contact

Muhib Mehdi

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⭐ Star this repo if you find it useful!

Made with ❤️ by Muhib Mehdi