ByteArray values over 127 (0x7f) causes OverFlow error

[trinidadestrada]

When using python to pass a list as a byte array, an OverFlow error will occur if values greater than 127 (0x7f) are passed.

I came across this using my android device.

Below is a simple (not practical) example which can be used to cause this error:

from jnius import autoclass

OutputStream = autoclass('java.io.OutputStream')
FileOutputStream = autoclass('java.io.FileOutputStream')
BufferedOutputStream = autoclass('java.io.BufferedOutputStream')
outstream = BufferedOutputStream(FileOutputStream('/path/to/test.txt'))
outstream.write([ 0x6f, 0x7a, 0x7f])
outstream.write([ 0x80 ])
outstream.flush()

The app crash should occur at the line containing outstream.write([ 0x80 ]) as demonstrated by my trace log:

I/python  ( 1631):  Traceback (most recent call last):
I/python  ( 1631):    File "main.py", line 61, in <module>
I/python  ( 1631):      main()
I/python  ( 1631):    File "main.py", line 58, in main
I/python  ( 1631):      run_app()
I/python  ( 1631):    File "main.py", line 53, in run_app
I/python  ( 1631):      shell.run()
I/python  ( 1631):    File "/home/joe/projects/shell/build/python-for-android/build/python-install/lib/python2.7/site-packages/kivy/app.py", line 600, in run
I/python  ( 1631):    File "/home/joe/projects/shell/build/python-for-android/build/python-install/lib/python2.7/site-packages/kivy/base.py", line 454, in runTouchApp
I/python  ( 1631):    File "/home/joe/projects/shell/build/python-for-android/build/python-install/lib/python2.7/site-packages/kivy/core/window/window_pygame.py", line 325, in mainloop
I/python  ( 1631):    File "/home/joe/projects/shell/build/python-for-android/build/python-install/lib/python2.7/site-packages/kivy/core/window/window_pygame.py", line 231, in _mainloop
I/python  ( 1631):    File "/home/joe/projects/shell/build/python-for-android/build/python-install/lib/python2.7/site-packages/kivy/base.py", line 294, in idle
I/python  ( 1631):    File "/home/joe/projects/shell/build/python-for-android/build/python-install/lib/python2.7/site-packages/kivy/clock.py", line 370, in tick
I/python  ( 1631):    File "/home/joe/projects/shell/build/python-for-android/build/python-install/lib/python2.7/site-packages/kivy/clock.py", line 481, in _process_events
I/python  ( 1631):    File "/home/joe/projects/shell/build/python-for-android/build/python-install/lib/python2.7/site-packages/kivy/clock.py", line 280, in tick
I/python  ( 1631):    File "/mnt/sdcard/com.test.shell.app4/view/screens.py", line 86, in start_cb
I/python  ( 1631):      control.splash.load(manager)
I/python  ( 1631):    File "/mnt/sdcard/com.test.shell.app4/control/splash.py", line 3, in load
I/python  ( 1631):      screen_manager.switch_screen("home")
I/python  ( 1631):    File "/mnt/sdcard/com.test.shell.app4/view/screens.py", line 177, in switch_screen
I/python  ( 1631):      self.push(screen_type, *args, **kwargs)
I/python  ( 1631):    File "/mnt/sdcard/com.test.shell.app4/view/screens.py", line 129, in push
I/python  ( 1631):      s = screen_class(*args, **kwargs)
I/python  ( 1631):    File "/mnt/sdcard/com.test.shell.app4/view/screens.py", line 39, in __init__
I/python  ( 1631):      layout = home.build_home_screen()
I/python  ( 1631):    File "/mnt/sdcard/com.test.shell.app4/view/home.py", line 98, in build_home_screen
I/python  ( 1631):      test_out_stream()
I/python  ( 1631):    File "/mnt/sdcard/com.test.shell.app4/view/home.py", line 65, in test_out_stream
I/python  ( 1631):      outstream.write([ 0x80 ])
I/python  ( 1631):    File "jnius_export_class.pxi", line 830, in jnius.jnius.JavaMultipleMethod.__call__ (jnius/jnius.c:20536)
I/python  ( 1631):    File "jnius_export_class.pxi", line 556, in jnius.jnius.JavaMethod.__call__ (jnius/jnius.c:17394)
I/python  ( 1631):    File "jnius_conversion.pxi", line 96, in jnius.jnius.populate_args (jnius/jnius.c:5899)
I/python  ( 1631):    File "jnius_conversion.pxi", line 448, in jnius.jnius.convert_pyarray_to_java (jnius/jnius.c:8966)
I/python  ( 1631):  OverflowError: value too large to convert to signed char
I/python  ( 1631): Python for android ended.

[jiangjianxiao]

I have the same problem, can fix it?

from jnius import autoclass
ByteArrayInputStream = autoclass('java.io.ByteArrayInputStream')
v = open('xxx.xls', 'rb').read()

ms = ByteArrayInputStream(v)

raise OverflowError: value too large to convert to jbyte

[ccdavid]

Same problem here. Any news about this?

[vilasmaciel]

Same here, any workaround?

[ccdavid]

I was able to work around it by converting the characters to integers between -127 and 126. Like this:

[ord(b) if ord(b) <= 127 else ord(b)-256 for b in bstr]

The problem is caused because java uses sign bytes as chars.

[ccdavid]

I meant from -128 to 127.

[limodou]

This problem seems still existed.

[limodou]

I made mistake, the bug has been fiexed.