Re: [Jython-users] NullPointerException error when calling a python method

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Hi Robert,<br>
Thanks for the advice, <br>
<br>
&gt;There is a class naming problem.=A0 The class statement defines<br>
&gt;&quot;tryJythonSample&quot;, but the initializer tries to initialize
the<br>
&gt;class &quot;tryJython&quot; in its @sig string.<br>
<br>
ahaha, don't know how I was blind/dumb enough to miss something as simple
as that. Must have been half-asleep when I miss-typed that. Oh well.
:P<br>
<br>
&gt;&gt; import tryJythonSample.*;<br>
&gt;<br>
&gt;This import might be a problem.=A0 Unless you used the jythonc
--package<br>
&gt;(-p) option to specify the tryJythonSample package, you should just
use<br>
&gt;the following import:<br>
&gt;<br>
&gt;import tryJythonSample<br>
<br>
still having problems...<br>
<br>
tried the 'import tryJythonSample'&nbsp; (without using the jythonc
--package option)<br>
<br>
<font color=3D"#0000FF"><i>Exception in thread &quot;main&quot;
java.lang.NullPointerException<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
org.python.core.PyJavaClass.lookup(PyJavaClass.java:39)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
org.python.core.PyObject.&lt;init&gt;(PyObject.java:46)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
org.python.core.PySingleton.&lt;init&gt;(PySingleton.java:8)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
org.python.core.PyNone.&lt;init&gt;(PyNone.java:7)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
org.python.core.PySystemState.initStaticFields(PySystemState.java:341<br>
)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
org.python.core.PySystemState.initialize(PySystemState.java:320)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
org.python.core.Py.initProperties(Py.java:665)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
org.python.core.Py.initProxy(Py.java:709)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
tryJythonSample.&lt;init&gt;(tryJythonSample.java:105)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
tryJythonMain.main(tryJythonMain.java:8)<br>
<br>
</font></i><font color=3D"#000000">tried the 'import tryJythonSample.* when
using the jythonc --package option.<br>
got the error<br>
<br>
</font><font color=3D"#0000FF"><i>C:\Hubert\Work\Projects\tryJython\tryJytho=
nProject&gt;java
tryJythonMain<br>
Exception in thread &quot;main&quot; java.lang.NullPointerException<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
org.python.core.PyJavaClass.lookup(PyJavaClass.java:39)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
org.python.core.PyObject.&lt;init&gt;(PyObject.java:46)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
org.python.core.PySingleton.&lt;init&gt;(PySingleton.java:8)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
org.python.core.PyNone.&lt;init&gt;(PyNone.java:7)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
org.python.core.PySystemState.initStaticFields(PySystemState.java:341<br>
)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
org.python.core.PySystemState.initialize(PySystemState.java:320)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
org.python.core.Py.initProperties(Py.java:665)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
org.python.core.Py.initProxy(Py.java:709)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
tryJythonSample.tryJythonSample.&lt;init&gt;(tryJythonSample.java:107)<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; at
tryJythonMain.main(tryJythonMain.java:8)<br>
<br>
<br>
</font></i><font color=3D"#000000">error wise, unless I'm mistaken, it
seems to be running into the same problem each time <br>
Any ideas?<br>
<br>
Hubert<br>
<br>
<br>
(for others, here's the code...)<br>
<br>
import org.python.core.*;<br>
import tryJythonSample;<br>
<br>
public class tryJythonMain<br>
{<br>
 public static void main(String[] args)<br>
 {<br>
  tryJythonSample jySample =3D new tryJythonSample();<br>
  jySample.makeObject();<br>
=20
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbs=
p;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&n=
bsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;=
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbs=
p;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&n=
bsp;&nbsp;
<br>
 }<br>
}<br>
<br>
import java<br>
class tryJythonSample(java.lang.Object):<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; def __init__(self):<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
&quot;@sig public tryJythonSample()&quot;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; print
&quot;Constructor for tryJythonSample&quot;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; def makeObject(self):<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
&quot;@sig public void makeObject()&quot;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; print
&quot;I have just called a python method!!&quot;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br>
<br>
<br>
</font>
<BR>
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