| name | jar-explorer |
| description | Explore contents of JAR files and decompile Java class files. Use when you need to understand the internal structure of a JAR, view its manifest, or read the source code of a compiled .class file. |
JAR Explorer Skill
This skill provides tools and procedures for exploring Java Archive (JAR) files and decompiling their contents into readable Java source code.
Key Features
- List JAR Contents: Enumerate all files and directories inside a JAR.
- View Manifest: Extract and display the
META-INF/MANIFEST.MF file.
- Decompile Class Files: Convert
.class files back to .java source code using the bundled CFR decompiler.
- Extract Resources: Extract any file from the JAR to the local filesystem.
Workflows
1. List Contents of a JAR
To see what's inside a JAR file, use the jar_explorer.py script:
python3 scripts/jar_explorer.py list <path_to_jar>
2. View the Manifest
The manifest file often contains metadata like the version and main class:
python3 scripts/jar_explorer.py manifest <path_to_jar>
3. Decompile a Class File
To decompile a specific class file into Java source, use the decompile.sh script. This requires Java (JRE) to be installed in the environment.
./scripts/decompile.sh <path_to_jar> <fully_qualified_class_name> [output_directory]
The script uses the CFR decompiler (assets/cfr-0.152.jar).
4. Extract a Specific File
If you need to pull a resource (e.g., a .properties or .xml file) out of the JAR:
python3 scripts/jar_explorer.py extract <path_to_jar> <file_path_in_jar>
Troubleshooting
- Java Not Found: The decompiler requires Java. If
java is not in your path, you will only be able to list and extract files.
- Class Not Found: When decompiling, ensure you use the fully qualified class name (e.g.,
com.example.Main) or the path inside the JAR (e.g., com/example/Main.class).
- Permissions: Ensure scripts in the
scripts/ directory have execution permissions (chmod +x scripts/decompile.sh).
Bundled Resources
- scripts/jar_explorer.py: Python script for listing, manifest viewing, and extraction.
- scripts/decompile.sh: Shell script wrapper for the CFR decompiler.
- assets/cfr-0.152.jar: The CFR Java decompiler.
