pyjnius/README.md

PyJNIus
=======

A Python module to access Java classes as Python classes using JNI.
Warning: the pypi name is now `pyjnius` instead of `jnius`.

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Installation
------------

Requirements: Cython

```
pip install Cython
pip install pyjnius
```

Quick overview
--------------

```python
>>> from jnius import autoclass
>>> autoclass('java.lang.System').out.println('Hello world')
Hello world

>>> Stack = autoclass('java.util.Stack')
>>> stack = Stack()
>>> stack.push('hello')
>>> stack.push('world')
>>> print stack.pop()
world
>>> print stack.pop()
hello
```

Usage on desktop
----------------

You need a Java Development Kit (JDK) installed (OpenJDK will do), `Cython` and
`make` to build it. Please ensure that your `JDK_HOME` or `JAVA_HOME`
environment variable points to the installed JDK root directory, and that the
JVM library (`jvm.so` or `jvm.dll`) is available from your `PATH` environment
variable. **Failure to do so may result in a failed install, or a successful
install but inability to use the PyJNIus library.**

```
make
```

That's it! You can ensure everything is running correctly using::

```
make tests
```

Usage with python-for-android
-----------------------------

* Get [http://github.com/kivy/python-for-android]()
* Compile a distribution with kivy (PyJNIus will be automatically added)

Then, you can do this kind of things:

```python
from time import sleep
from jnius import autoclass

Hardware = autoclass('org.renpy.android.Hardware')
print 'DPI is', Hardware.getDPI()

Hardware.accelerometerEnable(True)
for x in xrange(20):
    print Hardware.accelerometerReading()
    sleep(.1)
```

It will output something like:

```
I/python  ( 5983): Android kivy bootstrap done. __name__ is __main__
I/python  ( 5983): Run user program, change dir and execute main.py
I/python  ( 5983): DPI is 160
I/python  ( 5983): [0.0, 0.0, 0.0]
I/python  ( 5983): [-0.0095768067985773087, 9.3852710723876953, 2.2218191623687744]
I/python  ( 5983): [-0.0095768067985773087, 9.3948478698730469, 2.2218191623687744]
I/python  ( 5983): [-0.0095768067985773087, 9.3948478698730469, 2.2026655673980713]
I/python  ( 5983): [-0.028730420395731926, 9.4044246673583984, 2.2122423648834229]
I/python  ( 5983): [-0.019153613597154617, 9.3852710723876953, 2.2026655673980713]
I/python  ( 5983): [-0.028730420395731926, 9.3852710723876953, 2.2122423648834229]
I/python  ( 5983): [-0.0095768067985773087, 9.3852710723876953, 2.1835119724273682]
I/python  ( 5983): [-0.0095768067985773087, 9.3756942749023438, 2.1835119724273682]
I/python  ( 5983): [0.019153613597154617, 9.3948478698730469, 2.2122423648834229]
I/python  ( 5983): [0.038307227194309235, 9.3852710723876953, 2.2218191623687744]
I/python  ( 5983): [-0.028730420395731926, 9.3948478698730469, 2.2026655673980713]
I/python  ( 5983): [-0.028730420395731926, 9.3852710723876953, 2.2122423648834229]
I/python  ( 5983): [-0.038307227194309235, 9.3756942749023438, 2.2026655673980713]
I/python  ( 5983): [0.3926490843296051, 9.3086557388305664, 1.3311761617660522]
I/python  ( 5983): [-0.10534487664699554, 9.4331550598144531, 2.1068975925445557]
I/python  ( 5983): [0.26815059781074524, 9.3469638824462891, 2.3463177680969238]
I/python  ( 5983): [-0.1149216815829277, 9.3852710723876953, 2.31758713722229]
I/python  ( 5983): [-0.038307227194309235, 9.41400146484375, 1.8674772977828979]
I/python  ( 5983): [0.13407529890537262, 9.4235782623291016, 2.2026655673980713]
```

Advanced example
----------------

When you use `autoclass`, it will discover all the methods and fields of the
class and resolve them. You may want to declare and use only what you
need. The previous example can be done manually as follows:

```python
from time import sleep
from jnius import MetaJavaClass, JavaClass, JavaMethod, JavaStaticMethod

class Hardware(JavaClass):
    __metaclass__ = MetaJavaClass
    __javaclass__ = 'org/renpy/android/Hardware'
    vibrate = JavaStaticMethod('(D)V')
    accelerometerEnable = JavaStaticMethod('(Z)V')
    accelerometerReading = JavaStaticMethod('()[F')
    getDPI = JavaStaticMethod('()I')
    
# use that new class!
print 'DPI is', Hardware.getDPI()

Hardware.accelerometerEnable()
for x in xrange(20):
    print Hardware.accelerometerReading()
    sleep(.1)
```

Support
-------

If you need assistance, you can ask for help on our mailing list:

* User Group : https://groups.google.com/group/kivy-users
* Email      : kivy-users@googlegroups.com

We also have a Discord server:

[https://chat.kivy.org/](https://chat.kivy.org/)

Contributing
------------

We love pull requests and discussing novel ideas. Check out our
[contribution guide](http://kivy.org/docs/contribute.html) and
feel free to improve PyJNIus.

The following mailing list and IRC channel are used exclusively for
discussions about developing the Kivy framework and its sister projects:

* Dev Group : https://groups.google.com/group/kivy-dev
* Email     : kivy-dev@googlegroups.com

License
-------

PyJNIus is released under the terms of the MIT License. Please refer to the
LICENSE file for more information.


## Backers

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