public T getAssembler()

in src/java/org/apache/turbine/services/assemblerbroker/util/python/PythonBaseFactory.java [71:156]
54 lines of code
5 McCabe index (conditional complexity)

    public T getAssembler(String subDirectory, String name)
            throws Exception
    {
        String path = conf.getString(PYTHON_PATH);

        if (StringUtils.isEmpty(path))
        {
            throw new Exception(
                "Python path not found - check your Properties");
        }

        log.debug("Screen name for JPython: {}", name);

        T assembler = null;

        String confName = path + "/" + PYTHON_CONFIG_FILE;

        // The filename of the Python script
        StringBuilder fName = new StringBuilder();

        fName.append(path);
        fName.append("/");
        fName.append(subDirectory);
        fName.append("/");
        fName.append(name.toLowerCase());
        fName.append(".py");

        File f = new File(fName.toString());

        if (f.exists())
        {
            // We try to open the Py Interpreter
            try (PythonInterpreter interp = new PythonInterpreter())
            {
                // Make sure the Py Interpreter use the right classloader
                // This is necessary for servlet engines generally has
                // their own classloader implementations and servlets aren't
                // loaded in the system classloader.  The python script will
                // load java package
                // org.apache.turbine.services.assemblerbroker.util.python;
                // the new classes to it as well.
                Py.getSystemState().setClassLoader(this.getClass().getClassLoader());

                // We import the Python SYS module. Now we don't need to do this
                // explicitly in the script.  We always use the sys module to
                // do stuff like loading java package
                // org.apache.turbine.services.assemblerbroker.util.python;
                interp.exec("import sys");

                // Now we try to load the script file
                interp.execfile(confName);
                interp.execfile(fName.toString());

                try
                {
                    // We create an instance of the screen class from the
                    // python script
                    interp.exec("scr = " + name + "()");
                }
                catch (Throwable e)
                {
                    throw new Exception(
                        "\nCannot create an instance of the python class.\n"
                        + "You probably gave your class the wrong name.\n"
                        + "Your class should have the same name as your "
                        + "filename.\nFilenames should be all lowercase and "
                        + "classnames should start with a capital.\n"
                        + "Expected class name: " + name + "\n");
                }

                // Here we convert the python screen instance to a java instance.
                @SuppressWarnings("unchecked") // Cast from Object necessary
				T t = (T) interp.get("scr", Assembler.class);
				assembler = t;
            }
            catch (Exception e)
            {
                // We log the error here because this code is not widely tested
                // yet. After we tested the code on a range of platforms this
                // won't be useful anymore.
                log.error("PYTHON SCRIPT SCREEN LOADER ERROR:", e);
                throw e;
            }
        }
        return assembler;
    }