jython-users

[Jython-users] Classpath/Classloader issue with Jython invoked via Tomcat/Velocity

[Travis B. <tb...@my...>]

I'm really puzzled by an issue I'm seeing running Jython.  I've 
compiled my scripts with jythonc into java class files.  These scripts 
import some classes from external jar files.  From the command line, 
everything runs just fine.  However, when I invoke the Jython scripts  
from inside Tomcat, they break because they can't locate any of the 
packages I try to import from.  The puzzling part is that other 
(non-Jython) code in my webapp imports the same pacakges just fine, and 
it's all running in the same VM.

Here is the Jython script Setup.py:

print "Entering Setup"

from org.jtmb.sql import DataEngine
from java.io import File

propsFile = File("conf/DataEngine.properties")
de = DataEngine.getStaticInstance(propsFile)
print de.getString("select version as name from branch")

Here is the code from the Velocity context where I statically invoke 
the jython script:

com.myrio.setup.Setup.main(new String[]{});

Here's an alternate effort in the Velocity context where I try to 
explicitly use the same classloader:

     ClassLoader loader = this.getClass().getClassLoader();
     Object setup = Class.forName("com.myrio.setup.Setup", true,
loader).newInstance();
     logger.fatal ("Attempting to load setup with custom classloader");
     ((com.myrio.setup.Setup) setup).main(new String[]{});


In both cases, I get the same result.  Here's the output in 
catalina.out.

Entering Setup
Traceback (innermost last):
   File "/home/travis/p4/3.5/qa/qas/code/jython/Setup.py", line 0, in 
main
ImportError: No module named jtmb



Thanks in advance -- this is my first effort at using classloaders, so 
I could easily be missing something.  I'm pretty sure I could get it to 
work by manually setting the classpath via system properties.  But that 
seems like a pretty broken approach.  Any help is appreciated!


-Travis

Re: [Jython-users] Classpath/Classloader issue with Jython invoked vi a Tomcat/Velocity

[Alexey N. S. <A.S...@md...>]

I think it indicates that your code is loaded by another (global?) class 
loader. Where do you have Jython jar installed?

- Alexey.

Travis Bear wrote:

>I'm really puzzled by an issue I'm seeing running Jython.  I've compiled
>my scripts with jythonc into java class files.  These scripts import
>some classes from external jar files.  From the command line, everything
>runs just fine.  However, when I invoke the Jython scripts  from inside
>Tomcat, they break because they can't locate any of the packages I try
>to import from.  The puzzling part is that other (non-Jython) code in my
>webapp imports the same pacakges just fine, and it's all running in the
>same VM. 
>
>Here is the Jython script Setup.py: 
>
>print "Entering Setup" 
>
>from org.jtmb.sql import DataEngine 
>from java.io import File 
>
>propsFile = File("conf/DataEngine.properties") 
>de = DataEngine.getStaticInstance(propsFile) 
>print de.getString("select version as name from branch") 
>
>Here is the code from the Velocity context where I statically invoke the
>jython script: 
>
>com.myrio.setup.Setup.main(new String[]{}); 
>
>Here's an alternate effort in the Velocity context where I try to
>explicitly use the same classloader: 
>
>    ClassLoader loader = this.getClass().getClassLoader(); 
>    Object setup = Class.forName("com.myrio.setup.Setup", true, 
>loader).newInstance(); 
>    logger.fatal ("Attempting to load setup with custom classloader"); 
>    ((com.myrio.setup.Setup) setup).main(new String[]{}); 
>
>
>In both cases, I get the same result.  Here's the output in
>catalina.out. 
>
>Entering Setup 
>Traceback (innermost last): 
>  File "/home/travis/p4/3.5/qa/qas/code/jython/Setup.py", line 0, in
>main 
>ImportError: No module named jtmb 
>
>
>
>Thanks in advance -- this is my first effort at using classloaders, so I
>could easily be missing something.  I'm pretty sure I could get it to
>work by manually setting the classpath via system properties.  But that
>seems like a pretty broken approach.  Any help is appreciated! 
>
>
>-Travis 
>
>  
>

-- 
------------------------------------------------------------------------
/ Alexey N. Solofnenko
home: http://trelony.cjb.net/
/

Re: [Jython-users] Classpath/Classloader issue with Jython invoked vi a Tomcat/Velocity

[Travis B. <tb...@my...>]

Alexey,

For this webapp, jython.jar is installed in 
$CATALINA_HOME/webapps/$WEBAPP_NAME/WEB-INF/lib/

If you are correct, is there a recommended way to override the 
classloader with one of my choosing?


Thanks!


-Travis


On Jan 31, 2005, at 2:55 PM, Alexey N. Solofnenko wrote:

>  I think it indicates that your code is loaded by another (global?) 
> class loader. Where do you have Jython jar installed?
>
>  - Alexey.
>
>  Travis Bear wrote:
> I'm really puzzled by an issue I'm seeing running Jython.  I've 
> compiled
> my scripts with jythonc into java class files.  These scripts import
> some classes from external jar files.  From the command line, 
> everything
> runs just fine.  However, when I invoke the Jython scripts  from inside
> Tomcat, they break because they can't locate any of the packages I try
> to import from.  The puzzling part is that other (non-Jython) code in 
> my
> webapp imports the same pacakges just fine, and it's all running in the
> same VM.
>
> Here is the Jython script Setup.py:
>
> print "Entering Setup"
>
> from org.jtmb.sql import DataEngine
> from java.io import File
>
> propsFile = File("conf/DataEngine.properties")
> de = DataEngine.getStaticInstance(propsFile)
> print de.getString("select version as name from branch")
>
> Here is the code from the Velocity context where I statically invoke 
> the
> jython script:
>
> com.myrio.setup.Setup.main(new String[]{});
>
> Here's an alternate effort in the Velocity context where I try to
> explicitly use the same classloader:
>
>     ClassLoader loader = this.getClass().getClassLoader();
>     Object setup = Class.forName("com.myrio.setup.Setup", true,
> loader).newInstance();
>     logger.fatal ("Attempting to load setup with custom classloader");
>     ((com.myrio.setup.Setup) setup).main(new String[]{});
>
>
> In both cases, I get the same result.  Here's the output in
> catalina.out.
>
> Entering Setup
> Traceback (innermost last):
>   File "/home/travis/p4/3.5/qa/qas/code/jython/Setup.py", line 0, in
> main
> ImportError: No module named jtmb
>
>
>
> Thanks in advance -- this is my first effort at using classloaders, so 
> I
> could easily be missing something.  I'm pretty sure I could get it to
> work by manually setting the classpath via system properties.  But that
> seems like a pretty broken approach.  Any help is appreciated!
>
>
> -Travis
>
>
>
>
>  --
>
>  Alexey N. Solofnenko
>  home: http://trelony.cjb.net/
>
>  _________________________________________________ Scanned on 31 Jan 
> 2005 22:57:33

Re: [Jython-users] Classpath/Classloader issue with Jython invoke d vi a Tomcat/Velocity

[Alexey N. S. <A.S...@md...>]

Tomcat handles all class loading. Please make sure that there is no 
jython.jar on a global classpath. Maybe your launcher (for example 
JBuilder) puts it onto Tomcat's classpath.

- Alexey.

Travis Bear wrote:

>Alexey, 
>
>For this webapp, jython.jar is installed in
>$CATALINA_HOME/webapps/$WEBAPP_NAME/WEB-INF/lib/ 
>
>If you are correct, is there a recommended way to override the
>classloader with one of my choosing? 
>
>
>Thanks! 
>
>
>-Travis 
>
>
>On Jan 31, 2005, at 2:55 PM, Alexey N. Solofnenko wrote: 
>
>
>  
>
>> I think it indicates that your code is loaded by another (global?)
>>class loader. Where do you have Jython jar installed? 
>>
>> - Alexey. 
>>
>> Travis Bear wrote: 
>>I'm really puzzled by an issue I'm seeing running Jython.  I've
>>compiled 
>>my scripts with jythonc into java class files.  These scripts import 
>>some classes from external jar files.  From the command line,
>>everything 
>>runs just fine.  However, when I invoke the Jython scripts  from
>>inside 
>>Tomcat, they break because they can't locate any of the packages I try
>>
>>to import from.  The puzzling part is that other (non-Jython) code in
>>my 
>>webapp imports the same pacakges just fine, and it's all running in
>>the 
>>same VM.  
>>
>>Here is the Jython script Setup.py:  
>>
>>print "Entering Setup"  
>>
>>from org.jtmb.sql import DataEngine  
>>from java.io import File  
>>
>>propsFile = File("conf/DataEngine.properties")  
>>de = DataEngine.getStaticInstance(propsFile)  
>>print de.getString("select version as name from branch")  
>>
>>Here is the code from the Velocity context where I statically invoke
>>the 
>>jython script:  
>>
>>com.myrio.setup.Setup.main(new String[]{});  
>>
>>Here's an alternate effort in the Velocity context where I try to 
>>explicitly use the same classloader:  
>>
>>    ClassLoader loader = this.getClass().getClassLoader();  
>>    Object setup = Class.forName("com.myrio.setup.Setup", true,  
>>loader).newInstance();  
>>    logger.fatal ("Attempting to load setup with custom classloader");
>>
>>    ((com.myrio.setup.Setup) setup).main(new String[]{});  
>>
>>
>>In both cases, I get the same result.  Here's the output in 
>>catalina.out.  
>>
>>Entering Setup  
>>Traceback (innermost last):  
>>  File "/home/travis/p4/3.5/qa/qas/code/jython/Setup.py", line 0, in 
>>main  
>>ImportError: No module named jtmb  
>>
>>
>>
>>Thanks in advance -- this is my first effort at using classloaders, so
>>I 
>>could easily be missing something.  I'm pretty sure I could get it to 
>>work by manually setting the classpath via system properties.  But
>>that 
>>seems like a pretty broken approach.  Any help is appreciated!  
>>
>>
>>-Travis  
>>
>>   
>>
>>
>> --  
>>
>> Alexey N. Solofnenko 
>> home: http://trelony.cjb.net/ 
>>  
>> _________________________________________________ Scanned on 31 Jan
>>2005 22:57:33
>>
>>    
>>