Thread: [Jython-users] how to: compiling jython class to java byte code (detailed)

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Sorry for posting twice but my fist mail wasn't detailed enough.

I want to use a Jython class in a Java class, so here is the source code
of the classes. The classes a not really useful they are only for
testing and get familiar with Jython.

=========== PyClass.py ==============
class PyClass:

    def echo(self, msg):
        "@sig public java.lang.String echo(java.lang.String msg)"

        ret = "selber: " + msg       
        return ret

========= JyUser.java =================

public class JyUser {
    public static void main(String[] args) {
        PyClass py = new PyClass();
        System.out.println(py.echo("echo"));
    }
}

The command jythonc PyClass.py produces the following error message:

=========================================================
Compiling .java to .class...
Compiling with args:
['C:\\Programme\\Java\\jdk1.5.0_01\\bin\\javac.exe', '-classpath',
'D:\\jython-2.1\\jython.jar;;.\\jpywork;;D:\\jython-2.1\\Tools\\jythonc;C:\\Dokumente
und
Einstellungen\\Robert\\Desktop\\jyc\\.;D:\\jython-2.1\\Lib;D:\\jython-2.1',
'.\\jpywork\\PyClass.java']
1  D:\jython-2.1\org\python\core\Py.java:989: as of release 1.4,
'assert' is a keyword, and may not be used as an identifier
(try -source 1.3 or lower to use 'assert' as an identifier)
    public static void assert(PyObject test, PyObject message) {
                       ^

D:\jython-2.1\org\python\core\Py.java:995: as of release 1.4, 'assert'
is a keyword, and may not be used as an identifier
(try -source 1.3 or lower to use 'assert' as an identifier)
    public static void assert(PyObject test) {
                       ^

D:\jython-2.1\org\python\core\Py.java:996: ')' expected
        assert(test, Py.None);
                   ^

D:\jython-2.1\org\python\parser\PythonGrammar.java:6739: as of release
1.5, 'enum' is a keyword, and may not be used as an identifier
(try -source 1.4 or lower to use 'enum' as an identifier)
      for (java.util.Enumeration enum = jj_expentries.elements();
enum.hasMoreElements();) {
                                 ^

D:\jython-2.1\org\python\parser\PythonGrammar.java:6739: as of release
1.5, 'enum' is a keyword, and may not be used as an identifier
(try -source 1.4 or lower to use 'enum' as an identifier)
      for (java.util.Enumeration enum = jj_expentries.elements();
enum.hasMoreElements();) {
                                                                  ^

D:\jython-2.1\org\python\parser\PythonGrammar.java:6740: as of release
1.5, 'enum' is a keyword, and may not be used as an identifier
(try -source 1.4 or lower to use 'enum' as an identifier)
        int[] oldentry = (int[])(enum.nextElement());
                                 ^

D:\jython-2.1\org\python\core\Py.java:996: incompatible types
found   : org.python.core.PyObject
required: boolean
        assert(test, Py.None);
               ^

D:\jython-2.1\org\python\core\PyBeanProperty.java:36: warning:
non-varargs call of varargs method with inexact argument type for last
parameter;
cast to java.lang.Object for a varargs call
cast to java.lang.Object[] for a non-varargs call and to suppress this
warning
            Object value = getMethod.invoke(iself, Py.EmptyObjects);
                                                     ^
=========================================================

Question 1:
I get it compiled with the command jythonc -J "-source 1.3" PyClass.py but I still get warnings. The 1.3 option is necessary because jythonc generates methodes named assert, which is a keyword since java 1.4 an I'm using jdk 1.5. So I wander if I made something wrong or Jython is only compatible with Java 1.3??? 

If I try to compile the java class file I get the following error message.

=========================================================

JyUser.java:4: cannot find symbol
symbol  : method echo(java.lang.String)
location: class PyClass
                System.out.println(py.echo("echo"));
                                     ^
1 error
=========================================================

Note that I already fixed the problem of finding the class (only a wrong classpath) but now I can't access the method of the Jython class also I used the @sig-docstring.

Question 2:
How to use Jython classes/methods from Java?

A general question on using this mailing list:
How to answer on mails? Replay to the sender or post a new message to the mailing list?

thanks
robert

Thread: [Jython-users] how to: compiling jython class to java byte code (detailed)

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