Re: [Jython-dev] Re: WEB-INF/classes & WEB-INF/lib/*.jar inaccessible in jython servlet

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

[finn]

> I have not yet look at this in depth, but I think the classes from lib &
> classes are available as classes, but not as jython package namespaces.
> You can test this by trying to load a class from withon the .py file
> with java.lang.Class.forName(). I guess this should work, but the normal
> jython import does not work.

[Brian Zhou]

>Unfortunately this (try load a <context>/WEB-INF/classes class from jython
>servlet with java.lang.Class.forName()) does not work.
>
>What I'm trying to do actually is putting XMLC (see http://xmlc.enhydra.org)
>compiled pages inside <context>.
>
>From within a jython servlet, "java.class.path" System property value does
>not include <context>/WEB-INF/classes at all. So basically jython servlet
>has no idea where to get these classes.
>
>Two observations, if I have testpkg.TestClass under
><context>/WEB-INF/classes:
>
>1. I happen to place org.python.util.PyServlet under tomcat_home/classes, if
>I add
>try {
>    Class.forName("testpkg.TestClass").newInstance();
>}
>catch (Exception ex) {
>    System.err.println(e.toString());
>}
>to PyServlet.java, class loading fails.

Right, but I'm not going to add any special support for this. The
PyServlet class (and the rest of jython.jar) should be placed under the
<context>/WEB-INF/lib.

>2. If I add the above code to a servlet within the same <context>, it loads
>okay.

Right, and it will load ok from within a jython script too.

>Which is reasonable, but also suggests that servlet class loading does
>something special when within a <context>. PyServlet need to borrow the same
>logic.

PyServlet will get the logic for free from the classloader that loaded
jython.jar (but only when jython.jar is loaded from
<context>/WEB-INF/lib). What we need to add is only the inspection of
classes and jars found on ../lib and ../classes. The actual classloading
magic is already handled by tomcat's servlet context logic.

> I didn't test JSP, but I believe it should be the same as servlet.

I have added this to PyServlet:

            props.setProperty("python.packages.directories",
                              "java.ext.dirs,pyservlet.lib");
            props.setProperty("pyservlet.lib",
                              rootPath + File.separator +
                              "WEB-INF" + File.separator +
                              "lib");

            props.setProperty("python.packages.paths",
                              "java.class.path,sun.boot.class.path,"+
                              "pyservlet.classes");
            props.setProperty("pyservlet.classes",
                              rootPath + File.separator +
                              "WEB-INF" + File.separator +
                              "classes");

It seems to work, but I think we should have some kind of direct API for
this purpose. 

  PySystemState.add_classpath(String directoryPath)
  PySystemState.add_extdirs(String directoryPath)

Any thoughs, Samuele?

regards,
finn