JPype is available either as a pre-compiled binary for Anaconda, or may be build from source though several methods.

Binary Install

JPype can be installed as pre-compiled binary if you are using the Anaconda Python stack. Binaries are available for Linux, OSX, ad windows are available on conda-forge.

  1. Ensure you have installed Anaconda/Miniconda. Instructions can be found here.

  2. Install from the conda-forge software channel:

    conda install -c conda-forge jpype1

Source Install

Installing from source requires

JPype works with CPython 2.6 or later including the 3 series. Both the runtime and the development package are required.
Either the Sun/Oracle JDK/JRE Variant or OpenJDK. Python 2.6+ (including Python 3+). JPype source distribution includes a copy of the Java JNI header and precompiled Java code, so the development kit is not required from the source distribution. JPype has been used with Java versions from Java 1.7 to Java 11.
A C++ compiler which matches the ABI used to build CPython.
Ant and JDK
(Optional) JPype contains sections of Java code. These sections are precompiled in the source distribution but must be build with installing from git directly.

Once these requirements have been met one can use pip to build either from the source distribution or directly from the repo. Specific requirements from different achitectures are shown below.

Build using pip

JPype may be build and installed with one easy step using pip.

To install the latest JPype using the source distribute use:

pip install JPype1

On some systems (e.g. Fedora Linux), this installation was found not to enable numpy support. If this happens, the following forces compilation and enables numpy support if it is available:

pip install --no-binary :all: JPype1

To install from the current github master use:

pip install git+

More details on installing from git can be found at Pip install. The git version does not include a prebuilt jar and thus both ant and JDK are required.

Build and install manually

JPype can be built entirely from source. Just follow these three easy steps.

1. Get the JPype source

Either from github or from PyPi.

2. Build the source with desired options

Compile JPype using the included script with:

python build

The setup script recognizes several arguments.

--ant Define the location of ant on your system using --ant=path. This option is useful when building when ant is not in the path.
 Force setup to recreate the jar from scratch.
 Build a verison of JPype with full logging to the console. This can be used to diagnose tricky JNI issues.
 Do not compile with numpy extenstions.

After building, JPype can be tested using the test bench. The test bench requires ant and JDK to build.

3. Test JPype with (optional):

python test

4. Install JPype with:

python install

If it fails…

This happens mostly due to the setup not being able to find your JAVA_HOME. In case this happens, please do two things:

  1. You can continue the installation by finding the JAVA_HOME on your own ( the place where the headers etc. are) and explicitly setting it for the installation:

    JAVA_HOME=/usr/lib/java/jdk1.8.0/ python install
  2. Please create an Issue on github and post all the information you have.

Specific requirements

JPype is known to work on Linx, OSX, Windows, and Cygwin. To make it easier to those who have not built CPython modules before here are some helpful tips for different machines.


Debian/Ubuntu users will have to install g++, python-dev, and ant (optional) Use:

sudo apt-get install g++ python-dev python3-dev ant


Windows users need a CPython installation and C++ compilers specificly for CPython:

  1. Install some version of Python (2.7 or higher), e.g., Anaconda is a good choice for users not yet familiar with the language
  2. For Python 2 series, Install Windows C++ Compiler
  3. For Python 3 series, Install Microsoft Visual Studio 2010 Redistributable Package (x64) and Microsoft Build Tools 2015 Update 3
  4. (optional) Install Apache Ant (tested using 1.9.13)

Netbeans ant can be used in place of Apache Ant. Netbeans ant is located in ${netbeans}/extide/ant/bin/ant.bat.

Due to differences in the C++ API, only the version specified will work to build CPython modules. The Build Tools 2015 is a pain to find. Microsoft really wants people to download the latest version. To get to it from the above URL, click on “Redistributables and Build Tools”, then select Microsoft Build Tools 2015 Update 3.

When building for windows you must use the Visual Studio developer command prompt.

Known Bugs/Limitations

  • Java classes outside of a package (in the <default>) cannot be imported.
  • Because of lack of JVM support, you cannot shutdown the JVM and then restart it.
  • Structural issues prevent managing objects from more than one JVM at a time.
  • Some methods rely on the “current” class/caller. Since calls coming directly from python code do not have a current class, these methods do not work. The User Guide lists all the known methods like that.
  • Mixing 64 bit Python with 32 bit Java and vice versa crashes on import jpype.