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  1. Application Security
  2. Modifying and Protecting Java Class Files
  3. Direct Bytecode Editing
  4. Steps to Directly Edit a Java Class File

Update: Java Bytecode Editing Tools

April 2025

Discover practical tools for Java bytecode editing tailored for modern needs. Check out CFR, Procyon, FernFlower, and Bytecode Viewer to simplify your decompiling and editing tasks, keeping things smooth and up-to-date for today’s Java versions.

1. CFR (Class File Reader):

  • Purpose: A modern Java decompiler capable of handling complex Java features, including lambdas and switch expressions.

  • Key Features: Supports up to Java 14, easily decompiles .class files into readable Java source code.

  • Download Link: CFR Download

  • Usage Example:

    bash

    java -jar cfr.jar path/to/ClassFile.class > DecompiledClass.java

2. Procyon:

  • Purpose: Designed to decompile Java bytecode into source code, excelling at reconstructing code involving synthetic constructs.

  • Key Features: Ideal for modern Java applications, supports Java features like lambdas and method references.

  • Download Link: Procyon GitHub Repository

3. FernFlower:

  • Purpose: A high-quality decompiler developed by JetBrains for accurately converting bytecode to human-readable source code.

  • Key Features: Handles complex bytecode structures seamlessly and is integrated into IntelliJ IDEA.

  • Download Link: FernFlower GitHub Page

4. Bytecode Viewer:

  • Purpose: A graphical user interface for analyzing, modifying, and decompiling Java bytecode.

  • Key Features: Combines multiple decompilers (CFR, FernFlower, Procyon), supports plugins, and can analyze Android APK/DEX files.

  • Download Link: Bytecode Viewer GitHub | SourceForge Mirror

These tools are highly capable and actively maintained, making them excellent choices for decompiling, analyzing, or editing Java bytecode effectively. Let me know if you need further details about any of these tools! 🚀

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