jdcli

jdcli is a lightweight command line interface tool to extract and decompile java classes in .jar files by using jd-core, the library behind JD-GUI.

This tool also supports extracting jar files with case-insensitive class name conflicts (which commonly occur in obfuscated jar files) on case-insensitive filesystems. It also does not stop when it fails to decompile a singular file, allowing complicated jar files crafted using different tools to still be analyzed.

Usage:

usage: jdcli <command> [arguments...]

valid commands:
  jdcli dj|decompile-jar <jar file> [output directory] [--verbose] [--skip-cleanup] - Decompile a jar file into a directory
  jdcli dcs|decompile-classes <directory> [--verbose] [--delete-class-files] - Decompile classes in a directory
  jdcli dc|decompile-class <base directory> <file> - Decompile a .class file
  jdcli cleanup <directory> - removes all .class files in a directory
  jdcli h|help - Show this menu
  jdcli v|version - Show version information

options:
  -v --verbose | Log additional debug information

Example: jdcli decompile-jar ./test.jar ./test.classes/

This can also be used with APK files by using a tool like dex2jar to convert it to a .jar file.

Installation

Installation requires Java/OpenJDK version >= 16. To install, download the latest jar file from the releases page.

If you use Linux or macOS, you may want to add alias jdcli="java -jar [jdcli jar location]" to your ~/.bashrc or ~/.zshrc so that you can invoke jdcli using just jdcli. Once you complete that and restart your terminal, you should be able to use jdcli. If you can't do this, you can always use java -jar [jdcli jar location] instead.

Commands

• jdcli dj|decompile-jar <jar file> [output directory] [--verbose] [--skip-cleanup]
  • Decompiles a .jar file into .java files
  • Arguments:
    • <jar file>: the .jar file to extract from
    • [output directory]: the directory to put the extracted files in (default: [jar path].classes/)
  • Options:
    • --verbose: adds heavy logging output (warning: it will spam your terminal), useful for debugging.
    • --skip-cleanup: skips removing .class files (this will use more storage per decompile)
• jdcli dcs|decompile-classes <directory> [--verbose] [--delete-class-files]
  • Recursively decompiles all .class files into .java files
  • Arguments:
    • <directory>: the target directory in which classes should be decompiled
  • Options:
    • --verbose: adds heavy logging output (warning: it will spam your terminal), useful for debugging.
    • --delete-class-files: deletes all .class files after decompiling is complete
• jdcli dc|decompile-class <base directory> <file>
  • Decompiles a specified .class file and shows any errors that occur
  • Arguments:
    • <base directory>: the directory that should be used as the base for the class (so it can identify packages)
    • <file>: the targeted .class file to decompile
• jdcli cleanup <directory>
  • Recursively removes all .class files in a directory
  • Arguments:
    • <directory>: the directory in which class files should be deleted
• jdcli h|help
  • Show the help menu
• jdcli v|version
  • Shows the version and a link to the releases page

Building

This project should be able to be imported into IntelliJ IDEA and have all dependencies installed using mvn install. To build, use mvn package. Note that the target version for jdcli is Java/OpenJDK 16.