pyjnius
A Python library for accessing access Java classes as using the Java Native Interface (JNI).
Decision gist · record as of 2026-08-14
Yes, if you need Python–Java interoperability. PyJNIus is actively maintained, MIT-licensed, widely used, has no known vulnerabilities, and ships pre-built wheels for modern Python versions. The main requirement is having a JDK installed and configured—a one-time setup cost. Install it if you're building a Kivy mobile app, integrating Python with Java libraries, or automating JVM-based systems.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- A Java Development Kit (JDK) must be installed and JAVA_HOME configured on Windows; on macOS and Linux, JDK is typically auto-detected.
- Medium install friction: the package ships pre-built wheels for Python 3.10, 3.11, 3.12, and 3.13 across macOS, Linux, Windows, and ARM platforms, but requires a Java Development Kit (JDK) to be installed and configured on your system.
- On Windows, JAVA_HOME must be set; on macOS and Linux it is usually auto-detected.
License · maintenance · safety
permissive license (permissive) — PyJNIus is MIT licensed (permissive), allowing free use, modification, and distribution with minimal restrictions—suitable for both open-source and commercial projects.
last release 2025-09-08 (340 days) · last repo commit 2026-08-12 · 1,482 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 295,263 downloads/mo, #7,927 on PyPI
Alternatives
Verify before relying
pip install pyjnius
from jnius import autoclass
Stack = autoclass('java.util.Stack')
stack = Stack()
stack.push('hello')
print(stack.pop())- Whether pre-built wheels include JNI headers or if compilation from source requires additional build tools.
- Performance overhead of the Python–Java bridge for high-frequency method calls.
- Compatibility with alternative JVM implementations beyond standard OpenJDK.
What it is and what it does
PyJNIus is a Python library that bridges Python and Java by exposing Java classes and methods to Python code via the Java Native Interface (JNI). It lets you instantiate Java objects, call methods, access fields, and work with Java data types directly from Python—all without writing native C code yourself. The library is managed by the Kivy team and works on desktop (macOS, Linux, Windows) and mobile (Android) platforms.
You can use it two ways: with autoclass() for dynamic discovery of all Java class members, or by manually declaring JavaClass subclasses with specific methods and fields for finer control. It's commonly used in Kivy mobile apps to access Android hardware and in desktop applications that need to leverage existing Java libraries or interact with the JVM.
Use it for
- Access Android hardware sensors and APIs from a Python mobile app built with Kivy.
- Call Java utility classes and data structures from Python without rewriting them.
- Integrate Python scripts with existing Java libraries or legacy Java codebases on desktop systems.
- Build cross-platform mobile apps where Python handles UI logic and Java handles platform-specific functionality.
- Prototype or automate Java applications by scripting them from Python.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes, if you need Python–Java interoperability.
PyJNIus is actively maintained, MIT-licensed, widely used, has no known vulnerabilities, and ships pre-built wheels for modern Python versions. The main requirement is having a JDK installed and configured—a one-time setup cost. Install it if you're building a Kivy mobile app, integrating Python with Java libraries, or automating JVM-based systems.
Install
pyjnius on PyPI
Before you install
Medium install friction: the package ships pre-built wheels for Python 3.10, 3.11, 3.12, and 3.13 across macOS, Linux, Windows, and ARM platforms, but requires a Java Development Kit (JDK) to be installed and configured on your system. On Windows, JAVA_HOME must be set; on macOS and Linux it is usually auto-detected. The project is actively maintained with recent activity.
A Java Development Kit (JDK) must be installed and JAVA_HOME configured on Windows; on macOS and Linux, JDK is typically auto-detected.
License in practice
PyJNIus is MIT licensed (permissive), allowing free use, modification, and distribution with minimal restrictions—suitable for both open-source and commercial projects.
Quickstart
pip install pyjnius
from jnius import autoclass
Stack = autoclass('java.util.Stack')
stack = Stack()
stack.push('hello')
print(stack.pop())Verify before relying
- Whether pre-built wheels include JNI headers or if compilation from source requires additional build tools.
- Performance overhead of the Python–Java bridge for high-frequency method calls.
- Compatibility with alternative JVM implementations beyond standard OpenJDK.
Package facts
| License | permissive license permissive |
| Python support | Not specified |
| Install friction | Medium. Platform-specific wheel |
| Runtime dependencies | None |
| Maintenance | Actively maintained 340 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 295,263 / month, #7,927 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 5 - Production/StableIntended Audience :: DevelopersLicense :: OSI Approved :: MIT LicenseNatural Language :: EnglishOperating System :: AndroidOperating System :: MacOSOperating System :: Microsoft :: WindowsOperating System :: POSIX :: LinuxProgramming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.9Topic :: Software Development :: Libraries :: Application Frameworks |
Evidence: pyjnius-1.7.0-cp310-cp310-macosx_10_9_universal2.whl; pyjnius-1.7.0-cp310-cp310-macosx_10_9_x86_64.whl; pyjnius-1.7.0-cp310-cp310-manylinux2014_aarch64.manylinux_2_17_aarch64.manylinux_2_28_aarch64.whl; pyjnius-1.7.0-cp310-cp310-manylinux2014_x86_64.manylinux_2_17_x86_64.manylinux_2_28_x86_64.whl; pyjnius-1.7.0-cp310-cp310-win32.whl; pyjnius-1.7.0-cp310-cp310-win_amd64.whl; pyjnius-1.7.0-cp311-cp311-macosx_10_9_universal2.whl; pyjnius-1.7.0-cp311-cp311-macosx_10_9_x86_64.whl; pyjnius-1.7.0-cp311-cp311-manylinux2014_aarch64.manylinux_2_17_aarch64.manylinux_2_28_aarch64.whl; pyjnius-1.7.0-cp311-cp311-manylinux2014_x86_64.manylinux_2_17_x86_64.manylinux_2_28_x86_64.whl; pyjnius-1.7.0-cp311-cp311-win32.whl; pyjnius-1.7.0-cp311-cp311-win_amd64.whl; pyjnius-1.7.0-cp312-cp312-macosx_10_13_universal2.whl; pyjnius-1.7.0-cp312-cp312-macosx_10_13_x86_64.whl; pyjnius-1.7.0-cp312-cp312-manylinux2014_aarch64.manylinux_2_17_aarch64.manylinux_2_28_aarch64.whl; pyjnius-1.7.0-cp312-cp312-manylinux2014_x86_64.manylinux_2_17_x86_64.manylinux_2_28_x86_64.whl; pyjnius-1.7.0-cp312-cp312-win32.whl; pyjnius-1.7.0-cp312-cp312-win_amd64.whl; pyjnius-1.7.0-cp313-cp313-macosx_10_13_universal2.whl; pyjnius-1.7.0-cp313-cp313-macosx_10_13_x86_64.whl
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