jython-users

[Jython-users] implementing an interface (multple inheritance)

[Eric F. <eri...@ny...>]

I would like to integrate some jython into a java source tree.  Some of my
python modules will need to import classes defined in this project, and in
at least one case, I need to implement a jython class with multiple
inheritance from a java class and a java interface.  How must I do this?

Finally, are jython objects serializable?

A demo sourcetree of a trival hybrid jython & java program would be VERY
helpful.

Many thanks, Eric

---
Eric Freudenthal // Courant Institute // New York University
office: 212-998-3345  // cell:917-279-6208
715 Broadway, Room 1011, New York, NY  10003
cell pager: eri...@fr... (100 char limit)

Re: [Jython-users] implementing an interface (multple inheritance)

[Ype K. <yk...@xs...>]

Eric,

>I would like to integrate some jython into a java source tree.  Some of my
>python modules will need to import classes defined in this project, and in
>at least one case, I need to implement a jython class with multiple
>inheritance from a java class and a java interface.  How must I do this?

Look under 'Interacting with java packages' at:
http://jython.sourceforge.net/docs/index.html

You cannot directly use multiple inheritance from java classes or
interfaces. The workaround is to wrap the java things in Jython first:

import pack1 # java packages on the class path when invoking jython.
import pack2

class wrapintf(pack1.someJavaInterface):
    pass
    # I don't know whether you actually have to implement the interface here.

class wrapcls(pack2.someJavaClass):
    pass

class whatYouAskedFor(wrapcls, wrapintf):
    pass

Off course you can add features to the wrappers before inheriting
from them.


>Finally, are jython objects serializable?

I have never done this, but there is a pickle module as in CPython, iirc.
In case you need Java serialisation: i don't know.

>
>A demo sourcetree of a trival hybrid jython & java program would be VERY
>helpful.

Have a look at Treedemo.py and Console.py in Demos/swing in the jython
distribution. Definitely worth a look for everyone who ever used swing.

Good luck,
Ype

Re: [Jython-users] implementing an interface (multple inheritance)

[<bc...@wo...>]

On Wed, 25 Apr 2001 20:30:50 +0100, you wrote:

>Eric,
>
>>I would like to integrate some jython into a java source tree.  Some of my
>>python modules will need to import classes defined in this project, and in
>>at least one case, I need to implement a jython class with multiple
>>inheritance from a java class and a java interface.  How must I do this?
>
>Look under 'Interacting with java packages' at:
>http://jython.sourceforge.net/docs/index.html
>
>You cannot directly use multiple inheritance from java classes or
>interfaces. The workaround is to wrap the java things in Jython first:
>
>import pack1 # java packages on the class path when invoking jython.
>import pack2
>
>class wrapintf(pack1.someJavaInterface):
>    pass
>    # I don't know whether you actually have to implement the interface here.
>
>class wrapcls(pack2.someJavaClass):
>    pass
>
>class whatYouAskedFor(wrapcls, wrapintf):
>    pass

You don't have to wrap the java classes/interfaces:

  class whatYouAskedFor(pack2.someJavaClass, pack1.someJavaInterface):
      def interface_method1(self):
         pass
      def interface_method2(self):
         pass

will work as well.

regards,
finn

Re: [Jython-users] implementing an interface (multple inheritance)

[<bc...@wo...>]

[Eric Freudenthal]

>I would like to integrate some jython into a java source tree.  Some of my
>python modules will need to import classes defined in this project, and in
>at least one case, I need to implement a jython class with multiple
>inheritance from a java class and a java interface.  How must I do this?

See other post in the thread.

>Finally, are jython objects serializable?

Yes, but when reading a serialized stream you must use the 

   org.python.util.PythonObjectInputStream

instead of the normal ObjectInputStream class. This utility class will
help when resolving python classes that subclass java classes.

regards,
finn