How to Use Quiltflower, a Modern Java Decompiler

Do you want to decompile Java bytecode into readable source code? Do you want to learn how a library or a framework works, or fix a bug in a legacy application??If yes, then you need Quiltflower, a modern Java decompiler that is accurate, fast, and user-friendly.

Here are some bullet points for why you should use Quiltflower:

• It supports new language features like try with resources, switch expressions, pattern matching, and more
• It generates better control flow for loops, try-catch, switch, etc
• It can be used as an Intellij IDEA plugin, or from the command line
• It is open source and licensed under the Apache Licence Version 2.0
• It is actively developed and welcomes contributions and feedback

In this article, I will show you how to use Quiltflower from the command line and as an Intellij IDEA plugin. I will also show you some examples of how Quiltflower decompiles a simple hello world program.

How to Use Quiltflower from the Command Line

To use Quiltflower from the command line, you need to download the latest release from the GitHub repository?and run it with some options and arguments. Here is the basic syntax:

java -jar quiltflower.jar [-<option>=<value>]* [<source>]+ <destination>

Here is an example of how to use Quiltflower from the command line to decompile a hello world program:

java -jar quiltflower.jar c:\Temp\binary\HelloWorld.class c:\Temp\source\

This command will decompile the?HelloWorld.class?file and save it in the?c:\Temp\source\?directory.

Here is the original source code of the hello world program:

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello World!");
    }
}        

And here is the decompiled source code by Quiltflower:

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello World!");
    }
}        

As you can see, Quiltflower preserves the original structure and formatting of the code.

How to Use Quiltflower as an Intellij IDEA Plugin

To use Quiltflower as an Intellij IDEA plugin, you need to download it from the JetBrains Marketplace?or from within your IDE (File -> Settings -> Plugins -> Marketplace -> Search for “Quiltflower”). After installing it, you need to restart your IDE.

To use Quiltflower as an Intellij IDEA plugin, you just need to right-click on any class file in your project or in an external library and select “Show Bytecode With Quiltflower”. This will open a new tab with the decompiled source code of the class. You can also double-click on any method or field in the bytecode view to jump to its definition in the source code view.

To modify the settings of Quiltflower from Intellij IDEA, you need to go to File -> Settings -> Editor -> File Types -> Quiltflower Decompiler. Here you can change various options such as indentation, line numbers, renaming, etc.

Conclusion

Quiltflower is a great tool for reverse engineering Java classes and learning how they work. If you want to learn more about Quiltflower, you can visit the GitHub repository, where you can find the source code, documentation, and issues. Happy decompiling! ??