Accessing static java methods in Python through jython

Question

I am currently trying to access a static class in java, within python. I import as normal, then I try to get the class instance of the java class.

from com.exmaple.util import Foo

Foo. __class___.run_static_method()

This doesn't seem to work. suggestions? What am i doing wrong.

In Java, you would do this: `Foo.someStaticMethod()` Does that work for you or doesn't that work with jython? — thejh, Nov 25 '10 at 17:32
Please provide some more detail about what exactly is happening. Check that you are not using same method_name in caller and the called class.http://bugs.jython.org/issue1002 — Puspendu Banerjee, Nov 25 '10 at 17:39

score 2 · Answer 1 · answered Nov 25 '10 at 17:37

2

Try using

Foo.run_static_method()

answered Nov 25 '10 at 17:37

ThiefMaster

310,957
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score 1 · Answer 2 · edited May 23 '17 at 11:58

I ran into this with a class only holding static methods:

public class foo {
     public static void bar() {
         ...
     }
}

Adding a dummy constructor helped in my case. I guess this is because of pythons nature were classes are actually already objects (there is a long post about metaclasses giving some details about class understanding in python, its worthy a read eventhough it is a different topic), and jython trying to make the class an object before running the function eventhough it is static. I f this would be true that might be a bug report. (I am testing on jython2.5).

update: I don't consider my theroy for thecause to likely since I believe Java has some pure static classes as well. However the solution resolved the issue twice.

with dummy constructor:

public class foo {

     public foo() {}   //!This dummy constructor did the trick for me

     public static void bar() {
         ...
     }

}

score 1 · Answer 3 · answered Jun 18 '13 at 05:46

I ran into this problem, too. There's a gotcha that the other answerers are unaware of. If the Java class doesn't have the keyword public, then its static methods will not be available to Jython. This is confusing because it's independent of whether the methods themselves are public, and other ways of accessing the not-explicitly-public class work, such as instantiation. In summary, do this:

public class foo {
    public static void bar() { ... }
}

not this:

class foo {
    public static void bar() { ... }
}

score 1 · Answer 4 · answered Nov 25 '10 at 17:43

1

I suppose you create an instance of the class and just call the method on that.

from com.example.util import Foo

foo = Foo()
foo.run_static_method()

Assuming just doing Foo.run_static_method() doesn't work.

answered Nov 25 '10 at 17:43

Peter C

6,219
1
25
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score 1 · Answer 5 · answered Nov 25 '10 at 18:00

It works like this example:

Jython 2.5.1 (Release_2_5_1:6813, Sep 26 2009, 13:47:54) 
[Java HotSpot(TM) Client VM (Sun Microsystems Inc.)] on java1.6.0_22
Type "help", "copyright", "credits" or "license" for more information.
>>> import java.lang
>>> java.lang.System.getProperty('user.dir')
u'/home/vinay'

Note that getProperty is a static method of static class java.lang.System.

Accessing static java methods in Python through jython

5 Answers5