[Jython-users] Newbie question

[James H. <jh...@pa...>]

Hi,

So far I think Jython is pretty cool... but I've got a problem/question...

First off, here's my sample code:

"MyMap.java"
===========================================
import java.io.Serializable;
import java.util.HashMap;

public
class MyMap
{
   private HashMap hash = new HashMap(10);

   public
   void MyMap()
   {
   }

   public
   void setAttribute(String key, Object attr)
   {
     hash.put(key, attr);
   }

   public
   Object getAtrribute(String key)
   {
     return hash.get(key);
   }

   public static
   void main(String[] args)
   {
     Properties props = new Properties();
     props.setProperty("jython.home", "/jython");
     PythonInterpreter.initialize(System.getProperties(),props,new String[0]);

     MyMap theMap = new MyMap();

     theMap.setAttribute("myAttr", "myAttr is cool");

     PythonInterpreter interp = new PythonInterpreter();
     interp.set("theMap", theMap);

     interp.exec("print theMap.getAtrribute(\"myAttr\")");
     interp.exec("theMap.setAttribute(\"crapKey\", \"crapVal\")");

     MyMap newMap = (MyMap)interp.get("theMap", MyMap.class);
     System.err.println("GotBack: " +  (String)newMap.getAtrribute("crapKey"));

   }
}

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

This works just fine, as intended by printing
the output:

	myAttr is cool
	GotBack: crapVal


My problem is that I really need the method

   void setAttribute(String key, Object attr)

to be this:

   void setAttribute(String key, Serializable attr)

But when I make that change, rather than the
expected output, I get:

	myAttr is cool
	Exception in thread "main" java.lang.ClassCastException: 
org.python.core.PyString
         		at com.partnet.prototypes.mops.unittest.MyMap.main(MyMap.java:72)


Can someone explain this to me? I really need
to restrict the input objects to be of type Serializable.

Thanks,
James