java:

LoadPythonStuff(String modulePath, String moduleName)
{
    PySystemState state = new PySystemState();
    state.append(modulePath)

    PyObject importer = state.builtins.__getitem(Py.newString("__import__"));
    PyObject module = importer.__call__(Py.newString(moduleName));
}

LoadPythonStuff("/path/to/foo", "bar")
thrown ImportError module not found

jython console:

import sys
sys.append("/path/to/foo")
__import__ bar